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coral / busybox / f2b846e27718624e697cd87e9f4025826dea9ff2 / . / shell / hush.c
blob: 032482c6d9f12d0bda1a70381ea838ed49f772de [file] [log] [blame]
/* vi: set sw=4 ts=4: */
/*
* sh.c -- a prototype Bourne shell grammar parser
* Intended to follow the original Thompson and Ritchie
* "small and simple is beautiful" philosophy, which
* incidentally is a good match to today's BusyBox.
*
* Copyright (C) 2000,2001 Larry Doolittle <larry@doolittle.boa.org>
*
* Credits:
* The parser routines proper are all original material, first
* written Dec 2000 and Jan 2001 by Larry Doolittle. The
* execution engine, the builtins, and much of the underlying
* support has been adapted from busybox-0.49pre's lash, which is
* Copyright (C) 1999-2004 by Erik Andersen <andersen@codepoet.org>
* written by Erik Andersen <andersen@codepoet.org>. That, in turn,
* is based in part on ladsh.c, by Michael K. Johnson and Erik W.
* Troan, which they placed in the public domain. I don't know
* how much of the Johnson/Troan code has survived the repeated
* rewrites.
*
* Other credits:
* o_addchr() derived from similar w_addchar function in glibc-2.2.
* setup_redirect(), redirect_opt_num(), and big chunks of main()
* and many builtins derived from contributions by Erik Andersen
* miscellaneous bugfixes from Matt Kraai.
*
* There are two big (and related) architecture differences between
* this parser and the lash parser. One is that this version is
* actually designed from the ground up to understand nearly all
* of the Bourne grammar. The second, consequential change is that
* the parser and input reader have been turned inside out. Now,
* the parser is in control, and asks for input as needed. The old
* way had the input reader in control, and it asked for parsing to
* take place as needed. The new way makes it much easier to properly
* handle the recursion implicit in the various substitutions, especially
* across continuation lines.
*
* Bash grammar not implemented: (how many of these were in original sh?)
* $_
* &> and >& redirection of stdout+stderr
* Brace Expansion
* Tilde Expansion
* fancy forms of Parameter Expansion
* aliases
* Arithmetic Expansion
* <(list) and >(list) Process Substitution
* reserved words: case, esac, select, function
* Here Documents ( << word )
* Functions
* Major bugs:
* job handling woefully incomplete and buggy (improved --vda)
* reserved word execution woefully incomplete and buggy
* to-do:
* port selected bugfixes from post-0.49 busybox lash - done?
* change { and } from special chars to reserved words
* builtins: break, continue, eval, return, set, trap, ulimit
* test magic exec
* check setting of global_argc and global_argv
* follow IFS rules more precisely, including update semantics
* figure out what to do with backslash-newline
* propagate syntax errors, die on resource errors?
* continuation lines, both explicit and implicit - done?
* memory leak finding and plugging - done?
* maybe change charmap[] to use 2-bit entries
*
* Licensed under the GPL v2 or later, see the file LICENSE in this tarball.
*/
#include <glob.h> /* glob, of course */
/* #include <dmalloc.h> */
#include "busybox.h" /* for APPLET_IS_NOFORK/NOEXEC */
#if !BB_MMU && ENABLE_HUSH_TICK
//#undef ENABLE_HUSH_TICK
//#define ENABLE_HUSH_TICK 0
#warning On NOMMU, hush command substitution is dangerous.
#warning Dont use it for commands which produce lots of output.
#warning For more info see shell/hush.c, generate_stream_from_list().
#endif
#if !BB_MMU && ENABLE_HUSH_JOB
#undef ENABLE_HUSH_JOB
#define ENABLE_HUSH_JOB 0
#endif
#if !ENABLE_HUSH_INTERACTIVE
#undef ENABLE_FEATURE_EDITING
#define ENABLE_FEATURE_EDITING 0
#undef ENABLE_FEATURE_EDITING_FANCY_PROMPT
#define ENABLE_FEATURE_EDITING_FANCY_PROMPT 0
#endif
/* If you comment out one of these below, it will be #defined later
* to perform debug printfs to stderr: */
#define debug_printf(...) do {} while (0)
/* Finer-grained debug switches */
#define debug_printf_parse(...) do {} while (0)
#define debug_print_tree(a, b) do {} while (0)
#define debug_printf_exec(...) do {} while (0)
#define debug_printf_jobs(...) do {} while (0)
#define debug_printf_expand(...) do {} while (0)
#define debug_printf_glob(...) do {} while (0)
#define debug_printf_list(...) do {} while (0)
#define debug_printf_subst(...) do {} while (0)
#define debug_printf_clean(...) do {} while (0)
#ifndef debug_printf
#define debug_printf(...) fprintf(stderr, __VA_ARGS__)
#endif
#ifndef debug_printf_parse
#define debug_printf_parse(...) fprintf(stderr, __VA_ARGS__)
#endif
#ifndef debug_printf_exec
#define debug_printf_exec(...) fprintf(stderr, __VA_ARGS__)
#endif
#ifndef debug_printf_jobs
#define debug_printf_jobs(...) fprintf(stderr, __VA_ARGS__)
#define DEBUG_JOBS 1
#else
#define DEBUG_JOBS 0
#endif
#ifndef debug_printf_expand
#define debug_printf_expand(...) fprintf(stderr, __VA_ARGS__)
#define DEBUG_EXPAND 1
#else
#define DEBUG_EXPAND 0
#endif
#ifndef debug_printf_glob
#define debug_printf_glob(...) fprintf(stderr, __VA_ARGS__)
#define DEBUG_GLOB 1
#else
#define DEBUG_GLOB 0
#endif
#ifndef debug_printf_list
#define debug_printf_list(...) fprintf(stderr, __VA_ARGS__)
#endif
#ifndef debug_printf_subst
#define debug_printf_subst(...) fprintf(stderr, __VA_ARGS__)
#endif
#ifndef debug_printf_clean
/* broken, of course, but OK for testing */
static const char *indenter(int i)
{
static const char blanks[] ALIGN1 =
" ";
return &blanks[sizeof(blanks) - i - 1];
}
#define debug_printf_clean(...) fprintf(stderr, __VA_ARGS__)
#define DEBUG_CLEAN 1
#endif
#if DEBUG_EXPAND
static void debug_print_strings(const char *prefix, char **vv)
{
fprintf(stderr, "%s:\n", prefix);
while (*vv)
fprintf(stderr, " '%s'\n", *vv++);
}
#else
#define debug_print_strings(prefix, vv) ((void)0)
#endif
/*
* Leak hunting. Use hush_leaktool.sh for post-processing.
*/
#ifdef FOR_HUSH_LEAKTOOL
/* suppress "warning: no previous prototype..." */
void *xxmalloc(int lineno, size_t size);
void *xxrealloc(int lineno, void *ptr, size_t size);
char *xxstrdup(int lineno, const char *str);
void xxfree(void *ptr);
void *xxmalloc(int lineno, size_t size)
{
void *ptr = xmalloc((size + 0xff) & ~0xff);
fprintf(stderr, "line %d: malloc %p\n", lineno, ptr);
return ptr;
}
void *xxrealloc(int lineno, void *ptr, size_t size)
{
ptr = xrealloc(ptr, (size + 0xff) & ~0xff);
fprintf(stderr, "line %d: realloc %p\n", lineno, ptr);
return ptr;
}
char *xxstrdup(int lineno, const char *str)
{
char *ptr = xstrdup(str);
fprintf(stderr, "line %d: strdup %p\n", lineno, ptr);
return ptr;
}
void xxfree(void *ptr)
{
fprintf(stderr, "free %p\n", ptr);
free(ptr);
}
#define xmalloc(s) xxmalloc(__LINE__, s)
#define xrealloc(p, s) xxrealloc(__LINE__, p, s)
#define xstrdup(s) xxstrdup(__LINE__, s)
#define free(p) xxfree(p)
#endif
/* Keep unconditionally on for now */
#define HUSH_DEBUG 1
/* Do we support ANY keywords? */
#if ENABLE_HUSH_IF || ENABLE_HUSH_LOOPS
#define HAS_KEYWORDS 1
#define IF_HAS_KEYWORDS(...) __VA_ARGS__
#define IF_HAS_NO_KEYWORDS(...)
#else
#define HAS_KEYWORDS 0
#define IF_HAS_KEYWORDS(...)
#define IF_HAS_NO_KEYWORDS(...) __VA_ARGS__
#endif
#define SPECIAL_VAR_SYMBOL 3
#define PARSEFLAG_EXIT_FROM_LOOP 1
typedef enum {
REDIRECT_INPUT = 1,
REDIRECT_OVERWRITE = 2,
REDIRECT_APPEND = 3,
REDIRECT_HEREIS = 4,
REDIRECT_IO = 5
} redir_type;
/* The descrip member of this structure is only used to make
* debugging output pretty */
static const struct {
int mode;
signed char default_fd;
char descrip[3];
} redir_table[] = {
{ 0, 0, "()" },
{ O_RDONLY, 0, "<" },
{ O_CREAT|O_TRUNC|O_WRONLY, 1, ">" },
{ O_CREAT|O_APPEND|O_WRONLY, 1, ">>" },
{ O_RDONLY, -1, "<<" },
{ O_RDWR, 1, "<>" }
};
typedef enum {
PIPE_SEQ = 1,
PIPE_AND = 2,
PIPE_OR = 3,
PIPE_BG = 4,
} pipe_style;
typedef enum {
RES_NONE = 0,
#if ENABLE_HUSH_IF
RES_IF = 1,
RES_THEN = 2,
RES_ELIF = 3,
RES_ELSE = 4,
RES_FI = 5,
#endif
#if ENABLE_HUSH_LOOPS
RES_FOR = 6,
RES_WHILE = 7,
RES_UNTIL = 8,
RES_DO = 9,
RES_DONE = 10,
RES_IN = 11,
#endif
RES_XXXX = 12,
RES_SNTX = 13
} reserved_style;
/* This holds pointers to the various results of parsing */
struct p_context {
struct child_prog *child;
struct pipe *list_head;
struct pipe *pipe;
struct redir_struct *pending_redirect;
#if HAS_KEYWORDS
smallint ctx_res_w;
smallint ctx_inverted; /* "! cmd | cmd" */
int old_flag; /* bitmask of FLAG_xxx, for figuring out valid reserved words */
struct p_context *stack;
#endif
};
struct redir_struct {
struct redir_struct *next;
char *rd_filename; /* filename */
int fd; /* file descriptor being redirected */
int dup; /* -1, or file descriptor being duplicated */
smallint /*enum redir_type*/ rd_type;
};
struct child_prog {
pid_t pid; /* 0 if exited */
smallint is_stopped; /* is the program currently running? */
smallint subshell; /* flag, non-zero if group must be forked */
char **argv; /* program name and arguments */
struct pipe *group; /* if non-NULL, first in group or subshell */
struct redir_struct *redirects; /* I/O redirections */
struct pipe *family; /* pointer back to the child's parent pipe */
};
/* argv vector may contain variable references (^Cvar^C, ^C0^C etc)
* and on execution these are substituted with their values.
* Substitution can make _several_ words out of one argv[n]!
* Example: argv[0]=='.^C*^C.' here: echo .$*.
* References of the form ^C`cmd arg^C are `cmd arg` substitutions.
*/
struct pipe {
struct pipe *next;
int num_progs; /* total number of programs in job */
int alive_progs; /* number of programs running (not exited) */
int stopped_progs; /* number of programs alive, but stopped */
#if ENABLE_HUSH_JOB
int jobid; /* job number */
pid_t pgrp; /* process group ID for the job */
char *cmdtext; /* name of job */
#endif
struct child_prog *progs; /* array of commands in pipe */
smallint followup; /* PIPE_BG, PIPE_SEQ, PIPE_OR, PIPE_AND */
IF_HAS_KEYWORDS(smallint pi_inverted;) /* "! cmd | cmd" */
IF_HAS_KEYWORDS(smallint res_word;) /* needed for if, for, while, until... */
};
/* On program start, environ points to initial environment.
* putenv adds new pointers into it, unsetenv removes them.
* Neither of these (de)allocates the strings.
* setenv allocates new strings in malloc space and does putenv,
* and thus setenv is unusable (leaky) for shell's purposes */
#define setenv(...) setenv_is_leaky_dont_use()
struct variable {
struct variable *next;
char *varstr; /* points to "name=" portion */
int max_len; /* if > 0, name is part of initial env; else name is malloced */
smallint flg_export; /* putenv should be done on this var */
smallint flg_read_only;
};
typedef struct {
char *data;
int length;
int maxlen;
/* Misnomer! it's not "quoting", it's "protection against globbing"!
* (by prepending \ to *, ?, [ and to \ too) */
smallint o_quote;
smallint o_glob;
smallint nonnull;
smallint has_empty_slot;
smallint o_assignment; /* 0:maybe, 1:yes, 2:no */
} o_string;
enum {
MAYBE_ASSIGNMENT = 0,
DEFINITELY_ASSIGNMENT = 1,
NOT_ASSIGNMENT = 2,
};
/* Used for initialization: o_string foo = NULL_O_STRING; */
#define NULL_O_STRING { NULL }
/* I can almost use ordinary FILE *. Is open_memstream() universally
* available? Where is it documented? */
struct in_str {
const char *p;
/* eof_flag=1: last char in ->p is really an EOF */
char eof_flag; /* meaningless if ->p == NULL */
char peek_buf[2];
#if ENABLE_HUSH_INTERACTIVE
smallint promptme;
smallint promptmode; /* 0: PS1, 1: PS2 */
#endif
FILE *file;
int (*get) (struct in_str *);
int (*peek) (struct in_str *);
};
#define i_getch(input) ((input)->get(input))
#define i_peek(input) ((input)->peek(input))
enum {
CHAR_ORDINARY = 0,
CHAR_ORDINARY_IF_QUOTED = 1, /* example: *, # */
CHAR_IFS = 2, /* treated as ordinary if quoted */
CHAR_SPECIAL = 3, /* example: $ */
};
#define HUSH_VER_STR "0.02"
/* "Globals" within this file */
/* Sorted roughly by size (smaller offsets == smaller code) */
struct globals {
#if ENABLE_HUSH_INTERACTIVE
/* 'interactive_fd' is a fd# open to ctty, if we have one
* _AND_ if we decided to act interactively */
int interactive_fd;
const char *PS1;
const char *PS2;
#endif
#if ENABLE_FEATURE_EDITING
line_input_t *line_input_state;
#endif
pid_t root_pid;
#if ENABLE_HUSH_JOB
int run_list_level;
pid_t saved_task_pgrp;
pid_t saved_tty_pgrp;
int last_jobid;
struct pipe *job_list;
struct pipe *toplevel_list;
smallint ctrl_z_flag;
#endif
smallint fake_mode;
/* these three support $?, $#, and $1 */
char **global_argv;
int global_argc;
int last_return_code;
const char *ifs;
const char *cwd;
unsigned last_bg_pid;
struct variable *top_var; /* = &shell_ver (set in main()) */
struct variable shell_ver;
#if ENABLE_FEATURE_SH_STANDALONE
struct nofork_save_area nofork_save;
#endif
#if ENABLE_HUSH_JOB
sigjmp_buf toplevel_jb;
#endif
unsigned char charmap[256];
char user_input_buf[ENABLE_FEATURE_EDITING ? BUFSIZ : 2];
};
#define G (*ptr_to_globals)
#if !ENABLE_HUSH_INTERACTIVE
enum { interactive_fd = 0 };
#endif
#if !ENABLE_HUSH_JOB
enum { run_list_level = 0 };
#endif
#if ENABLE_HUSH_INTERACTIVE
#define interactive_fd (G.interactive_fd )
#define PS1 (G.PS1 )
#define PS2 (G.PS2 )
#endif
#if ENABLE_FEATURE_EDITING
#define line_input_state (G.line_input_state)
#endif
#define root_pid (G.root_pid )
#if ENABLE_HUSH_JOB
#define run_list_level (G.run_list_level )
#define saved_task_pgrp (G.saved_task_pgrp )
#define saved_tty_pgrp (G.saved_tty_pgrp )
#define last_jobid (G.last_jobid )
#define job_list (G.job_list )
#define toplevel_list (G.toplevel_list )
#define toplevel_jb (G.toplevel_jb )
#define ctrl_z_flag (G.ctrl_z_flag )
#endif /* JOB */
#define global_argv (G.global_argv )
#define global_argc (G.global_argc )
#define last_return_code (G.last_return_code)
#define ifs (G.ifs )
#define fake_mode (G.fake_mode )
#define cwd (G.cwd )
#define last_bg_pid (G.last_bg_pid )
#define top_var (G.top_var )
#define shell_ver (G.shell_ver )
#if ENABLE_FEATURE_SH_STANDALONE
#define nofork_save (G.nofork_save )
#endif
#if ENABLE_HUSH_JOB
#define toplevel_jb (G.toplevel_jb )
#endif
#define charmap (G.charmap )
#define user_input_buf (G.user_input_buf )
#define INIT_G() do { \
SET_PTR_TO_GLOBALS(xzalloc(sizeof(G))); \
} while (0)
#define JOB_STATUS_FORMAT "[%d] %-22s %.40s\n"
#if 1
/* Normal */
static void syntax(const char *msg)
{
/* Was using fancy stuff:
* (interactive_fd ? bb_error_msg : bb_error_msg_and_die)(...params...)
* but it SEGVs. ?! Oh well... explicit temp ptr works around that */
void (*fp)(const char *s, ...);
fp = (interactive_fd ? bb_error_msg : bb_error_msg_and_die);
fp(msg ? "%s: %s" : "syntax error", "syntax error", msg);
}
#else
/* Debug */
static void syntax_lineno(int line)
{
void (*fp)(const char *s, ...);
fp = (interactive_fd ? bb_error_msg : bb_error_msg_and_die);
fp("syntax error hush.c:%d", line);
}
#define syntax(str) syntax_lineno(__LINE__)
#endif
/* Index of subroutines: */
/* in_str manipulations: */
static int static_get(struct in_str *i);
static int static_peek(struct in_str *i);
static int file_get(struct in_str *i);
static int file_peek(struct in_str *i);
static void setup_file_in_str(struct in_str *i, FILE *f);
static void setup_string_in_str(struct in_str *i, const char *s);
/* "run" the final data structures: */
#if !defined(DEBUG_CLEAN)
#define free_pipe_list(head, indent) free_pipe_list(head)
#define free_pipe(pi, indent) free_pipe(pi)
#endif
static int free_pipe_list(struct pipe *head, int indent);
static int free_pipe(struct pipe *pi, int indent);
/* really run the final data structures: */
static int setup_redirects(struct child_prog *prog, int squirrel[]);
static int run_list(struct pipe *pi);
#if BB_MMU
#define pseudo_exec_argv(ptrs2free, argv) pseudo_exec_argv(argv)
#define pseudo_exec(ptrs2free, child) pseudo_exec(child)
#endif
static void pseudo_exec_argv(char **ptrs2free, char **argv) ATTRIBUTE_NORETURN;
static void pseudo_exec(char **ptrs2free, struct child_prog *child) ATTRIBUTE_NORETURN;
static int run_pipe(struct pipe *pi);
/* data structure manipulation: */
static int setup_redirect(struct p_context *ctx, int fd, redir_type style, struct in_str *input);
static void initialize_context(struct p_context *ctx);
static int done_word(o_string *dest, struct p_context *ctx);
static int done_command(struct p_context *ctx);
static void done_pipe(struct p_context *ctx, pipe_style type);
/* primary string parsing: */
static int redirect_dup_num(struct in_str *input);
static int redirect_opt_num(o_string *o);
#if ENABLE_HUSH_TICK
static int process_command_subs(o_string *dest,
struct in_str *input, const char *subst_end);
#endif
static int parse_group(o_string *dest, struct p_context *ctx, struct in_str *input, int ch);
static const char *lookup_param(const char *src);
static int handle_dollar(o_string *dest,
struct in_str *input);
static int parse_stream(o_string *dest, struct p_context *ctx, struct in_str *input0, const char *end_trigger);
/* setup: */
static int parse_and_run_stream(struct in_str *inp, int parse_flag);
static int parse_and_run_string(const char *s, int parse_flag);
static int parse_and_run_file(FILE *f);
/* job management: */
static int checkjobs(struct pipe* fg_pipe);
#if ENABLE_HUSH_JOB
static int checkjobs_and_fg_shell(struct pipe* fg_pipe);
static void insert_bg_job(struct pipe *pi);
static void remove_bg_job(struct pipe *pi);
static void delete_finished_bg_job(struct pipe *pi);
#else
int checkjobs_and_fg_shell(struct pipe* fg_pipe); /* never called */
#endif
/* local variable support */
static char **expand_strvec_to_strvec(char **argv);
/* used for eval */
static char *expand_strvec_to_string(char **argv);
/* used for expansion of right hand of assignments */
static char *expand_string_to_string(const char *str);
static struct variable *get_local_var(const char *name);
static int set_local_var(char *str, int flg_export);
static void unset_local_var(const char *name);
static int glob_needed(const char *s)
{
while (*s) {
if (*s == '\\')
s++;
if (*s == '*' || *s == '[' || *s == '?')
return 1;
s++;
}
return 0;
}
static int is_assignment(const char *s)
{
if (!s || !isalpha(*s))
return 0;
s++;
while (isalnum(*s) || *s == '_')
s++;
return *s == '=';
}
/* Replace each \x with x in place, return ptr past NUL. */
static char *unbackslash(char *src)
{
char *dst = src;
while (1) {
if (*src == '\\')
src++;
if ((*dst++ = *src++) == '\0')
break;
}
return dst;
}
static char **add_malloced_strings_to_strings(char **strings, char **add)
{
int i;
unsigned count1;
unsigned count2;
char **v;
v = strings;
count1 = 0;
if (v) {
while (*v) {
count1++;
v++;
}
}
count2 = 0;
v = add;
while (*v) {
count2++;
v++;
}
v = xrealloc(strings, (count1 + count2 + 1) * sizeof(char*));
v[count1 + count2] = NULL;
i = count2;
while (--i >= 0)
v[count1 + i] = add[i];
return v;
}
static char **add_malloced_string_to_strings(char **strings, char *add)
{
char *v[2];
v[0] = add;
v[1] = NULL;
return add_malloced_strings_to_strings(strings, v);
}
static void free_strings(char **strings)
{
if (strings) {
char **v = strings;
while (*v)
free(*v++);
free(strings);
}
}
#if !BB_MMU
#define EXTRA_PTRS 5 /* 1 for NULL, 1 for args, 3 for paranoid reasons */
static char **alloc_ptrs(char **argv)
{
char **v = argv;
while (*v)
v++;
return xzalloc((v - argv + EXTRA_PTRS) * sizeof(v[0]));
}
#endif
/* Function prototypes for builtins */
static int builtin_cd(char **argv);
static int builtin_echo(char **argv);
static int builtin_eval(char **argv);
static int builtin_exec(char **argv);
static int builtin_exit(char **argv);
static int builtin_export(char **argv);
#if ENABLE_HUSH_JOB
static int builtin_fg_bg(char **argv);
static int builtin_jobs(char **argv);
#endif
#if ENABLE_HUSH_HELP
static int builtin_help(char **argv);
#endif
static int builtin_pwd(char **argv);
static int builtin_read(char **argv);
static int builtin_test(char **argv);
static int builtin_true(char **argv);
static int builtin_set(char **argv);
static int builtin_shift(char **argv);
static int builtin_source(char **argv);
static int builtin_umask(char **argv);
static int builtin_unset(char **argv);
//static int builtin_not_written(char **argv);
/* Table of built-in functions. They can be forked or not, depending on
* context: within pipes, they fork. As simple commands, they do not.
* When used in non-forking context, they can change global variables
* in the parent shell process. If forked, of course they cannot.
* For example, 'unset foo | whatever' will parse and run, but foo will
* still be set at the end. */
struct built_in_command {
const char *cmd;
int (*function)(char **argv);
#if ENABLE_HUSH_HELP
const char *descr;
#define BLTIN(cmd, func, help) { cmd, func, help }
#else
#define BLTIN(cmd, func, help) { cmd, func }
#endif
};
/* For now, echo and test are unconditionally enabled.
* Maybe make it configurable? */
static const struct built_in_command bltins[] = {
BLTIN("." , builtin_source, "Run commands in a file"),
BLTIN(":" , builtin_true, "No-op"),
BLTIN("[" , builtin_test, "Test condition"),
BLTIN("[[" , builtin_test, "Test condition"),
#if ENABLE_HUSH_JOB
BLTIN("bg" , builtin_fg_bg, "Resume a job in the background"),
#endif
// BLTIN("break" , builtin_not_written, "Exit for, while or until loop"),
BLTIN("cd" , builtin_cd, "Change directory"),
// BLTIN("continue", builtin_not_written, "Continue for, while or until loop"),
BLTIN("echo" , builtin_echo, "Write strings to stdout"),
BLTIN("eval" , builtin_eval, "Construct and run shell command"),
BLTIN("exec" , builtin_exec, "Execute command, don't return to shell"),
BLTIN("exit" , builtin_exit, "Exit"),
BLTIN("export", builtin_export, "Set environment variable"),
#if ENABLE_HUSH_JOB
BLTIN("fg" , builtin_fg_bg, "Bring job into the foreground"),
BLTIN("jobs" , builtin_jobs, "List active jobs"),
#endif
BLTIN("pwd" , builtin_pwd, "Print current directory"),
BLTIN("read" , builtin_read, "Input environment variable"),
// BLTIN("return", builtin_not_written, "Return from a function"),
BLTIN("set" , builtin_set, "Set/unset shell local variables"),
BLTIN("shift" , builtin_shift, "Shift positional parameters"),
// BLTIN("trap" , builtin_not_written, "Trap signals"),
BLTIN("test" , builtin_test, "Test condition"),
// BLTIN("ulimit", builtin_not_written, "Control resource limits"),
BLTIN("umask" , builtin_umask, "Set file creation mask"),
BLTIN("unset" , builtin_unset, "Unset environment variable"),
#if ENABLE_HUSH_HELP
BLTIN("help" , builtin_help, "List shell built-in commands"),
#endif
};
/* Signals are grouped, we handle them in batches */
static void set_misc_sighandler(void (*handler)(int))
{
bb_signals(0
+ (1 << SIGINT)
+ (1 << SIGQUIT)
+ (1 << SIGTERM)
, handler);
}
#if ENABLE_HUSH_JOB
static void set_fatal_sighandler(void (*handler)(int))
{
bb_signals(0
+ (1 << SIGILL)
+ (1 << SIGTRAP)
+ (1 << SIGABRT)
+ (1 << SIGFPE)
+ (1 << SIGBUS)
+ (1 << SIGSEGV)
/* bash 3.2 seems to handle these just like 'fatal' ones */
+ (1 << SIGHUP)
+ (1 << SIGPIPE)
+ (1 << SIGALRM)
, handler);
}
static void set_jobctrl_sighandler(void (*handler)(int))
{
bb_signals(0
+ (1 << SIGTSTP)
+ (1 << SIGTTIN)
+ (1 << SIGTTOU)
, handler);
}
/* SIGCHLD is special and handled separately */
static void set_every_sighandler(void (*handler)(int))
{
set_fatal_sighandler(handler);
set_jobctrl_sighandler(handler);
set_misc_sighandler(handler);
signal(SIGCHLD, handler);
}
static void handler_ctrl_c(int sig ATTRIBUTE_UNUSED)
{
debug_printf_jobs("got sig %d\n", sig);
// as usual we can have all kinds of nasty problems with leaked malloc data here
siglongjmp(toplevel_jb, 1);
}
static void handler_ctrl_z(int sig ATTRIBUTE_UNUSED)
{
pid_t pid;
debug_printf_jobs("got tty sig %d in pid %d\n", sig, getpid());
pid = fork();
if (pid < 0) /* can't fork. Pretend there was no ctrl-Z */
return;
ctrl_z_flag = 1;
if (!pid) { /* child */
if (ENABLE_HUSH_JOB)
die_sleep = 0; /* let nofork's xfuncs die */
setpgrp();
debug_printf_jobs("set pgrp for child %d ok\n", getpid());
set_every_sighandler(SIG_DFL);
raise(SIGTSTP); /* resend TSTP so that child will be stopped */
debug_printf_jobs("returning in child\n");
/* return to nofork, it will eventually exit now,
* not return back to shell */
return;
}
/* parent */
/* finish filling up pipe info */
toplevel_list->pgrp = pid; /* child is in its own pgrp */
toplevel_list->progs[0].pid = pid;
/* parent needs to longjmp out of running nofork.
* we will "return" exitcode 0, with child put in background */
// as usual we can have all kinds of nasty problems with leaked malloc data here
debug_printf_jobs("siglongjmp in parent\n");
siglongjmp(toplevel_jb, 1);
}
/* Restores tty foreground process group, and exits.
* May be called as signal handler for fatal signal
* (will faithfully resend signal to itself, producing correct exit state)
* or called directly with -EXITCODE.
* We also call it if xfunc is exiting. */
static void sigexit(int sig) ATTRIBUTE_NORETURN;
static void sigexit(int sig)
{
/* Disable all signals: job control, SIGPIPE, etc. */
sigprocmask_allsigs(SIG_BLOCK);
if (interactive_fd)
tcsetpgrp(interactive_fd, saved_tty_pgrp);
/* Not a signal, just exit */
if (sig <= 0)
_exit(- sig);
kill_myself_with_sig(sig); /* does not return */
}
/* Restores tty foreground process group, and exits. */
static void hush_exit(int exitcode) ATTRIBUTE_NORETURN;
static void hush_exit(int exitcode)
{
fflush(NULL); /* flush all streams */
sigexit(- (exitcode & 0xff));
}
#else /* !JOB */
#define set_fatal_sighandler(handler) ((void)0)
#define set_jobctrl_sighandler(handler) ((void)0)
#define hush_exit(e) exit(e)
#endif /* JOB */
static const char *set_cwd(void)
{
if (cwd == bb_msg_unknown)
cwd = NULL; /* xrealloc_getcwd_or_warn(arg) calls free(arg)! */
cwd = xrealloc_getcwd_or_warn((char *)cwd);
if (!cwd)
cwd = bb_msg_unknown;
return cwd;
}
/*
* o_string support
*/
#define B_CHUNK (32 * sizeof(char*))
static void o_reset(o_string *o)
{
o->length = 0;
o->nonnull = 0;
if (o->data)
o->data[0] = '\0';
}
static void o_free(o_string *o)
{
free(o->data);
memset(o, 0, sizeof(*o));
}
static void o_grow_by(o_string *o, int len)
{
if (o->length + len > o->maxlen) {
o->maxlen += (2*len > B_CHUNK ? 2*len : B_CHUNK);
o->data = xrealloc(o->data, 1 + o->maxlen);
}
}
static void o_addchr(o_string *o, int ch)
{
debug_printf("o_addchr: '%c' o->length=%d o=%p\n", ch, o->length, o);
o_grow_by(o, 1);
o->data[o->length] = ch;
o->length++;
o->data[o->length] = '\0';
}
static void o_addstr(o_string *o, const char *str, int len)
{
o_grow_by(o, len);
memcpy(&o->data[o->length], str, len);
o->length += len;
o->data[o->length] = '\0';
}
static void o_addstr_duplicate_backslash(o_string *o, const char *str, int len)
{
while (len) {
o_addchr(o, *str);
if (*str++ == '\\'
&& (*str != '*' && *str != '?' && *str != '[')
) {
o_addchr(o, '\\');
}
len--;
}
}
/* My analysis of quoting semantics tells me that state information
* is associated with a destination, not a source.
*/
static void o_addqchr(o_string *o, int ch)
{
int sz = 1;
if (strchr("*?[\\", ch)) {
sz++;
o->data[o->length] = '\\';
o->length++;
}
o_grow_by(o, sz);
o->data[o->length] = ch;
o->length++;
o->data[o->length] = '\0';
}
static void o_addQchr(o_string *o, int ch)
{
int sz = 1;
if (o->o_quote && strchr("*?[\\", ch)) {
sz++;
o->data[o->length] = '\\';
o->length++;
}
o_grow_by(o, sz);
o->data[o->length] = ch;
o->length++;
o->data[o->length] = '\0';
}
static void o_addQstr(o_string *o, const char *str, int len)
{
if (!o->o_quote) {
o_addstr(o, str, len);
return;
}
while (len) {
char ch;
int sz;
int ordinary_cnt = strcspn(str, "*?[\\");
if (ordinary_cnt > len) /* paranoia */
ordinary_cnt = len;
o_addstr(o, str, ordinary_cnt);
if (ordinary_cnt == len)
return;
str += ordinary_cnt;
len -= ordinary_cnt + 1; /* we are processing + 1 char below */
ch = *str++;
sz = 1;
if (ch) { /* it is necessarily one of "*?[\\" */
sz++;
o->data[o->length] = '\\';
o->length++;
}
o_grow_by(o, sz);
o->data[o->length] = ch;
o->length++;
o->data[o->length] = '\0';
}
}
/* A special kind of o_string for $VAR and `cmd` expansion.
* It contains char* list[] at the beginning, which is grown in 16 element
* increments. Actual string data starts at the next multiple of 16 * (char*).
* list[i] contains an INDEX (int!) into this string data.
* It means that if list[] needs to grow, data needs to be moved higher up
* but list[i]'s need not be modified.
* NB: remembering how many list[i]'s you have there is crucial.
* o_finalize_list() operation post-processes this structure - calculates
* and stores actual char* ptrs in list[]. Oh, it NULL terminates it as well.
*/
#if DEBUG_EXPAND || DEBUG_GLOB
static void debug_print_list(const char *prefix, o_string *o, int n)
{
char **list = (char**)o->data;
int string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
int i = 0;
fprintf(stderr, "%s: list:%p n:%d string_start:%d length:%d maxlen:%d\n",
prefix, list, n, string_start, o->length, o->maxlen);
while (i < n) {
fprintf(stderr, " list[%d]=%d '%s' %p\n", i, (int)list[i],
o->data + (int)list[i] + string_start,
o->data + (int)list[i] + string_start);
i++;
}
if (n) {
const char *p = o->data + (int)list[n - 1] + string_start;
fprintf(stderr, " total_sz:%d\n", (p + strlen(p) + 1) - o->data);
}
}
#else
#define debug_print_list(prefix, o, n) ((void)0)
#endif
/* n = o_save_ptr_helper(str, n) "starts new string" by storing an index value
* in list[n] so that it points past last stored byte so far.
* It returns n+1. */
static int o_save_ptr_helper(o_string *o, int n)
{
char **list = (char**)o->data;
int string_start;
int string_len;
if (!o->has_empty_slot) {
string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
string_len = o->length - string_start;
if (!(n & 0xf)) { /* 0, 0x10, 0x20...? */
debug_printf_list("list[%d]=%d string_start=%d (growing)\n", n, string_len, string_start);
/* list[n] points to string_start, make space for 16 more pointers */
o->maxlen += 0x10 * sizeof(list[0]);
o->data = xrealloc(o->data, o->maxlen + 1);
list = (char**)o->data;
memmove(list + n + 0x10, list + n, string_len);
o->length += 0x10 * sizeof(list[0]);
} else
debug_printf_list("list[%d]=%d string_start=%d\n", n, string_len, string_start);
} else {
/* We have empty slot at list[n], reuse without growth */
string_start = ((n+1 + 0xf) & ~0xf) * sizeof(list[0]); /* NB: n+1! */
string_len = o->length - string_start;
debug_printf_list("list[%d]=%d string_start=%d (empty slot)\n", n, string_len, string_start);
o->has_empty_slot = 0;
}
list[n] = (char*)(ptrdiff_t)string_len;
return n + 1;
}
/* "What was our last o_save_ptr'ed position (byte offset relative o->data)?" */
static int o_get_last_ptr(o_string *o, int n)
{
char **list = (char**)o->data;
int string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
return ((int)(ptrdiff_t)list[n-1]) + string_start;
}
/* o_glob performs globbing on last list[], saving each result
* as a new list[]. */
static int o_glob(o_string *o, int n)
{
glob_t globdata;
int gr;
char *pattern;
debug_printf_glob("start o_glob: n:%d o->data:%p\n", n, o->data);
if (!o->data)
return o_save_ptr_helper(o, n);
pattern = o->data + o_get_last_ptr(o, n);
debug_printf_glob("glob pattern '%s'\n", pattern);
if (!glob_needed(pattern)) {
literal:
o->length = unbackslash(pattern) - o->data;
debug_printf_glob("glob pattern '%s' is literal\n", pattern);
return o_save_ptr_helper(o, n);
}
memset(&globdata, 0, sizeof(globdata));
gr = glob(pattern, 0, NULL, &globdata);
debug_printf_glob("glob('%s'):%d\n", pattern, gr);
if (gr == GLOB_NOSPACE)
bb_error_msg_and_die("out of memory during glob");
if (gr == GLOB_NOMATCH) {
globfree(&globdata);
goto literal;
}
if (gr != 0) { /* GLOB_ABORTED ? */
//TODO: testcase for bad glob pattern behavior
bb_error_msg("glob(3) error %d on '%s'", gr, pattern);
}
if (globdata.gl_pathv && globdata.gl_pathv[0]) {
char **argv = globdata.gl_pathv;
o->length = pattern - o->data; /* "forget" pattern */
while (1) {
o_addstr(o, *argv, strlen(*argv) + 1);
n = o_save_ptr_helper(o, n);
argv++;
if (!*argv)
break;
}
}
globfree(&globdata);
if (DEBUG_GLOB)
debug_print_list("o_glob returning", o, n);
return n;
}
/* If o->o_glob == 1, glob the string so far remembered.
* Otherwise, just finish current list[] and start new */
static int o_save_ptr(o_string *o, int n)
{
if (o->o_glob)
return o_glob(o, n); /* o_save_ptr_helper is inside */
return o_save_ptr_helper(o, n);
}
/* "Please convert list[n] to real char* ptrs, and NULL terminate it." */
static char **o_finalize_list(o_string *o, int n)
{
char **list;
int string_start;
n = o_save_ptr(o, n); /* force growth for list[n] if necessary */
if (DEBUG_EXPAND)
debug_print_list("finalized", o, n);
debug_printf_expand("finalized n:%d\n", n);
list = (char**)o->data;
string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
list[--n] = NULL;
while (n) {
n--;
list[n] = o->data + (int)(ptrdiff_t)list[n] + string_start;
}
return list;
}
/*
* in_str support
*/
static int static_get(struct in_str *i)
{
int ch = *i->p++;
if (ch == '\0') return EOF;
return ch;
}
static int static_peek(struct in_str *i)
{
return *i->p;
}
#if ENABLE_HUSH_INTERACTIVE
#if ENABLE_FEATURE_EDITING
static void cmdedit_set_initial_prompt(void)
{
#if !ENABLE_FEATURE_EDITING_FANCY_PROMPT
PS1 = NULL;
#else
PS1 = getenv("PS1");
if (PS1 == NULL)
PS1 = "\\w \\$ ";
#endif
}
#endif /* EDITING */
static const char* setup_prompt_string(int promptmode)
{
const char *prompt_str;
debug_printf("setup_prompt_string %d ", promptmode);
#if !ENABLE_FEATURE_EDITING_FANCY_PROMPT
/* Set up the prompt */
if (promptmode == 0) { /* PS1 */
free((char*)PS1);
PS1 = xasprintf("%s %c ", cwd, (geteuid() != 0) ? '$' : '#');
prompt_str = PS1;
} else {
prompt_str = PS2;
}
#else
prompt_str = (promptmode == 0) ? PS1 : PS2;
#endif
debug_printf("result '%s'\n", prompt_str);
return prompt_str;
}
static void get_user_input(struct in_str *i)
{
int r;
const char *prompt_str;
prompt_str = setup_prompt_string(i->promptmode);
#if ENABLE_FEATURE_EDITING
/* Enable command line editing only while a command line
* is actually being read */
do {
r = read_line_input(prompt_str, user_input_buf, BUFSIZ-1, line_input_state);
} while (r == 0); /* repeat if Ctrl-C */
i->eof_flag = (r < 0);
if (i->eof_flag) { /* EOF/error detected */
user_input_buf[0] = EOF; /* yes, it will be truncated, it's ok */
user_input_buf[1] = '\0';
}
#else
fputs(prompt_str, stdout);
fflush(stdout);
user_input_buf[0] = r = fgetc(i->file);
/*user_input_buf[1] = '\0'; - already is and never changed */
i->eof_flag = (r == EOF);
#endif
i->p = user_input_buf;
}
#endif /* INTERACTIVE */
/* This is the magic location that prints prompts
* and gets data back from the user */
static int file_get(struct in_str *i)
{
int ch;
/* If there is data waiting, eat it up */
if (i->p && *i->p) {
#if ENABLE_HUSH_INTERACTIVE
take_cached:
#endif
ch = *i->p++;
if (i->eof_flag && !*i->p)
ch = EOF;
} else {
/* need to double check i->file because we might be doing something
* more complicated by now, like sourcing or substituting. */
#if ENABLE_HUSH_INTERACTIVE
if (interactive_fd && i->promptme && i->file == stdin) {
do {
get_user_input(i);
} while (!*i->p); /* need non-empty line */
i->promptmode = 1; /* PS2 */
i->promptme = 0;
goto take_cached;
}
#endif
ch = fgetc(i->file);
}
debug_printf("file_get: got a '%c' %d\n", ch, ch);
#if ENABLE_HUSH_INTERACTIVE
if (ch == '\n')
i->promptme = 1;
#endif
return ch;
}
/* All the callers guarantee this routine will never be
* used right after a newline, so prompting is not needed.
*/
static int file_peek(struct in_str *i)
{
int ch;
if (i->p && *i->p) {
if (i->eof_flag && !i->p[1])
return EOF;
return *i->p;
}
ch = fgetc(i->file);
i->eof_flag = (ch == EOF);
i->peek_buf[0] = ch;
i->peek_buf[1] = '\0';
i->p = i->peek_buf;
debug_printf("file_peek: got a '%c' %d\n", *i->p, *i->p);
return ch;
}
static void setup_file_in_str(struct in_str *i, FILE *f)
{
i->peek = file_peek;
i->get = file_get;
#if ENABLE_HUSH_INTERACTIVE
i->promptme = 1;
i->promptmode = 0; /* PS1 */
#endif
i->file = f;
i->p = NULL;
}
static void setup_string_in_str(struct in_str *i, const char *s)
{
i->peek = static_peek;
i->get = static_get;
#if ENABLE_HUSH_INTERACTIVE
i->promptme = 1;
i->promptmode = 0; /* PS1 */
#endif
i->p = s;
i->eof_flag = 0;
}
/* squirrel != NULL means we squirrel away copies of stdin, stdout,
* and stderr if they are redirected. */
static int setup_redirects(struct child_prog *prog, int squirrel[])
{
int openfd, mode;
struct redir_struct *redir;
for (redir = prog->redirects; redir; redir = redir->next) {
if (redir->dup == -1 && redir->rd_filename == NULL) {
/* something went wrong in the parse. Pretend it didn't happen */
continue;
}
if (redir->dup == -1) {
char *p;
mode = redir_table[redir->rd_type].mode;
//TODO: check redir to names like '\\'
p = expand_string_to_string(redir->rd_filename);
openfd = open_or_warn(p, mode);
free(p);
if (openfd < 0) {
/* this could get lost if stderr has been redirected, but
bash and ash both lose it as well (though zsh doesn't!) */
return 1;
}
} else {
openfd = redir->dup;
}
if (openfd != redir->fd) {
if (squirrel && redir->fd < 3) {
squirrel[redir->fd] = dup(redir->fd);
}
if (openfd == -3) {
//close(openfd); // close(-3) ??!
} else {
dup2(openfd, redir->fd);
if (redir->dup == -1)
close(openfd);
}
}
}
return 0;
}
static void restore_redirects(int squirrel[])
{
int i, fd;
for (i = 0; i < 3; i++) {
fd = squirrel[i];
if (fd != -1) {
/* We simply die on error */
xmove_fd(fd, i);
}
}
}
/* Called after [v]fork() in run_pipe(), or from builtin_exec().
* Never returns.
* XXX no exit() here. If you don't exec, use _exit instead.
* The at_exit handlers apparently confuse the calling process,
* in particular stdin handling. Not sure why? -- because of vfork! (vda) */
static void pseudo_exec_argv(char **ptrs2free, char **argv)
{
int i, rcode;
char *p;
const struct built_in_command *x;
for (i = 0; is_assignment(argv[i]); i++) {
debug_printf_exec("pid %d environment modification: %s\n",
getpid(), argv[i]);
p = expand_string_to_string(argv[i]);
#if !BB_MMU
*ptrs2free++ = p;
#endif
putenv(p);
}
argv += i;
/* If a variable is assigned in a forest, and nobody listens,
* was it ever really set?
*/
if (!argv[0])
_exit(EXIT_SUCCESS);
argv = expand_strvec_to_strvec(argv);
#if !BB_MMU
*ptrs2free++ = (char*) argv;
#endif
/*
* Check if the command matches any of the builtins.
* Depending on context, this might be redundant. But it's
* easier to waste a few CPU cycles than it is to figure out
* if this is one of those cases.
*/
for (x = bltins; x != &bltins[ARRAY_SIZE(bltins)]; x++) {
if (strcmp(argv[0], x->cmd) == 0) {
debug_printf_exec("running builtin '%s'\n", argv[0]);
rcode = x->function(argv);
fflush(stdout);
_exit(rcode);
}
}
/* Check if the command matches any busybox applets */
#if ENABLE_FEATURE_SH_STANDALONE
if (strchr(argv[0], '/') == NULL) {
int a = find_applet_by_name(argv[0]);
if (a >= 0) {
if (APPLET_IS_NOEXEC(a)) {
debug_printf_exec("running applet '%s'\n", argv[0]);
// is it ok that run_applet_no_and_exit() does exit(), not _exit()?
run_applet_no_and_exit(a, argv);
}
/* re-exec ourselves with the new arguments */
debug_printf_exec("re-execing applet '%s'\n", argv[0]);
execvp(bb_busybox_exec_path, argv);
/* If they called chroot or otherwise made the binary no longer
* executable, fall through */
}
}
#endif
debug_printf_exec("execing '%s'\n", argv[0]);
execvp(argv[0], argv);
bb_perror_msg("cannot exec '%s'", argv[0]);
_exit(EXIT_FAILURE);
}
/* Called after [v]fork() in run_pipe()
*/
static void pseudo_exec(char **ptrs2free, struct child_prog *child)
{
if (child->argv)
pseudo_exec_argv(ptrs2free, child->argv);
if (child->group) {
#if !BB_MMU
bb_error_msg_and_die("nested lists are not supported on NOMMU");
#else
int rcode;
debug_printf_exec("pseudo_exec: run_list\n");
rcode = run_list(child->group);
/* OK to leak memory by not calling free_pipe_list,
* since this process is about to exit */
_exit(rcode);
#endif
}
/* Can happen. See what bash does with ">foo" by itself. */
debug_printf("trying to pseudo_exec null command\n");
_exit(EXIT_SUCCESS);
}
#if ENABLE_HUSH_JOB
static const char *get_cmdtext(struct pipe *pi)
{
char **argv;
char *p;
int len;
/* This is subtle. ->cmdtext is created only on first backgrounding.
* (Think "cat, <ctrl-z>, fg, <ctrl-z>, fg, <ctrl-z>...." here...)
* On subsequent bg argv is trashed, but we won't use it */
if (pi->cmdtext)
return pi->cmdtext;
argv = pi->progs[0].argv;
if (!argv || !argv[0]) {
pi->cmdtext = xzalloc(1);
return pi->cmdtext;
}
len = 0;
do len += strlen(*argv) + 1; while (*++argv);
pi->cmdtext = p = xmalloc(len);
argv = pi->progs[0].argv;
do {
len = strlen(*argv);
memcpy(p, *argv, len);
p += len;
*p++ = ' ';
} while (*++argv);
p[-1] = '\0';
return pi->cmdtext;
}
static void insert_bg_job(struct pipe *pi)
{
struct pipe *thejob;
int i;
/* Linear search for the ID of the job to use */
pi->jobid = 1;
for (thejob = job_list; thejob; thejob = thejob->next)
if (thejob->jobid >= pi->jobid)
pi->jobid = thejob->jobid + 1;
/* Add thejob to the list of running jobs */
if (!job_list) {
thejob = job_list = xmalloc(sizeof(*thejob));
} else {
for (thejob = job_list; thejob->next; thejob = thejob->next)
continue;
thejob->next = xmalloc(sizeof(*thejob));
thejob = thejob->next;
}
/* Physically copy the struct job */
memcpy(thejob, pi, sizeof(struct pipe));
thejob->progs = xzalloc(sizeof(pi->progs[0]) * pi->num_progs);
/* We cannot copy entire pi->progs[] vector! Double free()s will happen */
for (i = 0; i < pi->num_progs; i++) {
// TODO: do we really need to have so many fields which are just dead weight
// at execution stage?
thejob->progs[i].pid = pi->progs[i].pid;
/* all other fields are not used and stay zero */
}
thejob->next = NULL;
thejob->cmdtext = xstrdup(get_cmdtext(pi));
/* We don't wait for background thejobs to return -- append it
to the list of backgrounded thejobs and leave it alone */
printf("[%d] %d %s\n", thejob->jobid, thejob->progs[0].pid, thejob->cmdtext);
last_bg_pid = thejob->progs[0].pid;
last_jobid = thejob->jobid;
}
static void remove_bg_job(struct pipe *pi)
{
struct pipe *prev_pipe;
if (pi == job_list) {
job_list = pi->next;
} else {
prev_pipe = job_list;
while (prev_pipe->next != pi)
prev_pipe = prev_pipe->next;
prev_pipe->next = pi->next;
}
if (job_list)
last_jobid = job_list->jobid;
else
last_jobid = 0;
}
/* Remove a backgrounded job */
static void delete_finished_bg_job(struct pipe *pi)
{
remove_bg_job(pi);
pi->stopped_progs = 0;
free_pipe(pi, 0);
free(pi);
}
#endif /* JOB */
/* Check to see if any processes have exited -- if they
* have, figure out why and see if a job has completed */
static int checkjobs(struct pipe* fg_pipe)
{
int attributes;
int status;
#if ENABLE_HUSH_JOB
struct pipe *pi;
#endif
pid_t childpid;
int rcode = 0;
attributes = WUNTRACED;
if (fg_pipe == NULL)
attributes |= WNOHANG;
/* Do we do this right?
* bash-3.00# sleep 20 | false
* <ctrl-Z pressed>
* [3]+ Stopped sleep 20 | false
* bash-3.00# echo $?
* 1 <========== bg pipe is not fully done, but exitcode is already known!
*/
//FIXME: non-interactive bash does not continue even if all processes in fg pipe
//are stopped. Testcase: "cat | cat" in a script (not on command line)
// + killall -STOP cat
wait_more:
// TODO: safe_waitpid?
while ((childpid = waitpid(-1, &status, attributes)) > 0) {
int i;
const int dead = WIFEXITED(status) || WIFSIGNALED(status);
#if DEBUG_JOBS
if (WIFSTOPPED(status))
debug_printf_jobs("pid %d stopped by sig %d (exitcode %d)\n",
childpid, WSTOPSIG(status), WEXITSTATUS(status));
if (WIFSIGNALED(status))
debug_printf_jobs("pid %d killed by sig %d (exitcode %d)\n",
childpid, WTERMSIG(status), WEXITSTATUS(status));
if (WIFEXITED(status))
debug_printf_jobs("pid %d exited, exitcode %d\n",
childpid, WEXITSTATUS(status));
#endif
/* Were we asked to wait for fg pipe? */
if (fg_pipe) {
for (i = 0; i < fg_pipe->num_progs; i++) {
debug_printf_jobs("check pid %d\n", fg_pipe->progs[i].pid);
if (fg_pipe->progs[i].pid != childpid)
continue;
/* printf("process %d exit %d\n", i, WEXITSTATUS(status)); */
if (dead) {
fg_pipe->progs[i].pid = 0;
fg_pipe->alive_progs--;
if (i == fg_pipe->num_progs - 1) {
/* last process gives overall exitstatus */
rcode = WEXITSTATUS(status);
IF_HAS_KEYWORDS(if (fg_pipe->pi_inverted) rcode = !rcode;)
}
} else {
fg_pipe->progs[i].is_stopped = 1;
fg_pipe->stopped_progs++;
}
debug_printf_jobs("fg_pipe: alive_progs %d stopped_progs %d\n",
fg_pipe->alive_progs, fg_pipe->stopped_progs);
if (fg_pipe->alive_progs - fg_pipe->stopped_progs <= 0) {
/* All processes in fg pipe have exited/stopped */
#if ENABLE_HUSH_JOB
if (fg_pipe->alive_progs)
insert_bg_job(fg_pipe);
#endif
return rcode;
}
/* There are still running processes in the fg pipe */
goto wait_more; /* do waitpid again */
}
/* it wasnt fg_pipe, look for process in bg pipes */
}
#if ENABLE_HUSH_JOB
/* We asked to wait for bg or orphaned children */
/* No need to remember exitcode in this case */
for (pi = job_list; pi; pi = pi->next) {
for (i = 0; i < pi->num_progs; i++) {
if (pi->progs[i].pid == childpid)
goto found_pi_and_prognum;
}
}
/* Happens when shell is used as init process (init=/bin/sh) */
debug_printf("checkjobs: pid %d was not in our list!\n", childpid);
continue; /* do waitpid again */
found_pi_and_prognum:
if (dead) {
/* child exited */
pi->progs[i].pid = 0;
pi->alive_progs--;
if (!pi->alive_progs) {
printf(JOB_STATUS_FORMAT, pi->jobid,
"Done", pi->cmdtext);
delete_finished_bg_job(pi);
}
} else {
/* child stopped */
pi->progs[i].is_stopped = 1;
pi->stopped_progs++;
}
#endif
} /* while (waitpid succeeds)... */
/* wait found no children or failed */
if (childpid && errno != ECHILD)
bb_perror_msg("waitpid");
return rcode;
}
#if ENABLE_HUSH_JOB
static int checkjobs_and_fg_shell(struct pipe* fg_pipe)
{
pid_t p;
int rcode = checkjobs(fg_pipe);
/* Job finished, move the shell to the foreground */
p = getpgid(0); /* pgid of our process */
debug_printf_jobs("fg'ing ourself: getpgid(0)=%d\n", (int)p);
tcsetpgrp(interactive_fd, p);
// if (tcsetpgrp(interactive_fd, p) && errno != ENOTTY)
// bb_perror_msg("tcsetpgrp-4a");
return rcode;
}
#endif
/* run_pipe() starts all the jobs, but doesn't wait for anything
* to finish. See checkjobs().
*
* return code is normally -1, when the caller has to wait for children
* to finish to determine the exit status of the pipe. If the pipe
* is a simple builtin command, however, the action is done by the
* time run_pipe returns, and the exit code is provided as the
* return value.
*
* The input of the pipe is always stdin, the output is always
* stdout. The outpipe[] mechanism in BusyBox-0.48 lash is bogus,
* because it tries to avoid running the command substitution in
* subshell, when that is in fact necessary. The subshell process
* now has its stdout directed to the input of the appropriate pipe,
* so this routine is noticeably simpler.
*
* Returns -1 only if started some children. IOW: we have to
* mask out retvals of builtins etc with 0xff!
*/
static int run_pipe(struct pipe *pi)
{
int i;
int nextin;
int pipefds[2]; /* pipefds[0] is for reading */
struct child_prog *child;
const struct built_in_command *x;
char *p;
/* it is not always needed, but we aim to smaller code */
int squirrel[] = { -1, -1, -1 };
int rcode;
const int single_fg = (pi->num_progs == 1 && pi->followup != PIPE_BG);
debug_printf_exec("run_pipe start: single_fg=%d\n", single_fg);
#if ENABLE_HUSH_JOB
pi->pgrp = -1;
#endif
pi->alive_progs = 1;
pi->stopped_progs = 0;
/* Check if this is a simple builtin (not part of a pipe).
* Builtins within pipes have to fork anyway, and are handled in
* pseudo_exec. "echo foo | read bar" doesn't work on bash, either.
*/
child = &(pi->progs[0]);
if (single_fg && child->group && child->subshell == 0) {
debug_printf("non-subshell grouping\n");
setup_redirects(child, squirrel);
debug_printf_exec(": run_list\n");
rcode = run_list(child->group) & 0xff;
restore_redirects(squirrel);
debug_printf_exec("run_pipe return %d\n", rcode);
IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
return rcode;
}
if (single_fg && child->argv != NULL) {
char **argv_expanded;
char **argv = child->argv;
for (i = 0; is_assignment(argv[i]); i++)
continue;
if (i != 0 && argv[i] == NULL) {
/* assignments, but no command: set the local environment */
for (i = 0; argv[i] != NULL; i++) {
debug_printf("local environment set: %s\n", argv[i]);
p = expand_string_to_string(argv[i]);
set_local_var(p, 0);
}
return EXIT_SUCCESS; /* don't worry about errors in set_local_var() yet */
}
for (i = 0; is_assignment(argv[i]); i++) {
p = expand_string_to_string(argv[i]);
putenv(p);
//FIXME: do we leak p?!
}
for (x = bltins; x != &bltins[ARRAY_SIZE(bltins)]; x++) {
if (strcmp(argv[i], x->cmd) == 0) {
if (x->function == builtin_exec && argv[i+1] == NULL) {
debug_printf("magic exec\n");
setup_redirects(child, NULL);
return EXIT_SUCCESS;
}
debug_printf("builtin inline %s\n", argv[0]);
/* XXX setup_redirects acts on file descriptors, not FILEs.
* This is perfect for work that comes after exec().
* Is it really safe for inline use? Experimentally,
* things seem to work with glibc. */
setup_redirects(child, squirrel);
debug_printf_exec(": builtin '%s' '%s'...\n", x->cmd, argv[i+1]);
argv_expanded = expand_strvec_to_strvec(argv + i);
rcode = x->function(argv_expanded) & 0xff;
free(argv_expanded);
restore_redirects(squirrel);
debug_printf_exec("run_pipe return %d\n", rcode);
IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
return rcode;
}
}
#if ENABLE_FEATURE_SH_STANDALONE
{
int a = find_applet_by_name(argv[i]);
if (a >= 0 && APPLET_IS_NOFORK(a)) {
setup_redirects(child, squirrel);
save_nofork_data(&nofork_save);
argv_expanded = argv + i;
argv_expanded = expand_strvec_to_strvec(argv + i);
debug_printf_exec(": run_nofork_applet '%s' '%s'...\n", argv_expanded[0], argv_expanded[1]);
rcode = run_nofork_applet_prime(&nofork_save, a, argv_expanded);
free(argv_expanded);
restore_redirects(squirrel);
debug_printf_exec("run_pipe return %d\n", rcode);
IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
return rcode;
}
}
#endif
}
/* Disable job control signals for shell (parent) and
* for initial child code after fork */
set_jobctrl_sighandler(SIG_IGN);
/* Going to fork a child per each pipe member */
pi->alive_progs = 0;
nextin = 0;
for (i = 0; i < pi->num_progs; i++) {
#if !BB_MMU
char **ptrs2free = NULL;
#endif
child = &(pi->progs[i]);
if (child->argv) {
debug_printf_exec(": pipe member '%s' '%s'...\n", child->argv[0], child->argv[1]);
#if !BB_MMU
ptrs2free = alloc_ptrs(child->argv);
#endif
} else
debug_printf_exec(": pipe member with no argv\n");
/* pipes are inserted between pairs of commands */
pipefds[0] = 0;
pipefds[1] = 1;
if ((i + 1) < pi->num_progs)
xpipe(pipefds);
child->pid = BB_MMU ? fork() : vfork();
if (!child->pid) { /* child */
if (ENABLE_HUSH_JOB)
die_sleep = 0; /* let nofork's xfuncs die */
#if ENABLE_HUSH_JOB
/* Every child adds itself to new process group
* with pgid == pid_of_first_child_in_pipe */
if (run_list_level == 1 && interactive_fd) {
pid_t pgrp;
/* Don't do pgrp restore anymore on fatal signals */
set_fatal_sighandler(SIG_DFL);
pgrp = pi->pgrp;
if (pgrp < 0) /* true for 1st process only */
pgrp = getpid();
if (setpgid(0, pgrp) == 0 && pi->followup != PIPE_BG) {
/* We do it in *every* child, not just first,
* to avoid races */
tcsetpgrp(interactive_fd, pgrp);
}
}
#endif
xmove_fd(nextin, 0);
xmove_fd(pipefds[1], 1); /* write end */
if (pipefds[0] > 1)
close(pipefds[0]); /* read end */
/* Like bash, explicit redirects override pipes,
* and the pipe fd is available for dup'ing. */
setup_redirects(child, NULL);
/* Restore default handlers just prior to exec */
set_jobctrl_sighandler(SIG_DFL);
set_misc_sighandler(SIG_DFL);
signal(SIGCHLD, SIG_DFL);
pseudo_exec(ptrs2free, child); /* does not return */
}
#if !BB_MMU
free_strings(ptrs2free);
#endif
if (child->pid < 0) { /* [v]fork failed */
/* Clearly indicate, was it fork or vfork */
bb_perror_msg(BB_MMU ? "fork" : "vfork");
} else {
pi->alive_progs++;
#if ENABLE_HUSH_JOB
/* Second and next children need to know pid of first one */
if (pi->pgrp < 0)
pi->pgrp = child->pid;
#endif
}
if (i)
close(nextin);
if ((i + 1) < pi->num_progs)
close(pipefds[1]); /* write end */
/* Pass read (output) pipe end to next iteration */
nextin = pipefds[0];
}
if (!pi->alive_progs) {
debug_printf_exec("run_pipe return 1 (all forks failed, no children)\n");
return 1;
}
debug_printf_exec("run_pipe return -1 (%u children started)\n", pi->alive_progs);
return -1;
}
#ifndef debug_print_tree
static void debug_print_tree(struct pipe *pi, int lvl)
{
static const char *PIPE[] = {
[PIPE_SEQ] = "SEQ",
[PIPE_AND] = "AND",
[PIPE_OR ] = "OR" ,
[PIPE_BG ] = "BG" ,
};
static const char *RES[] = {
[RES_NONE ] = "NONE" ,
#if ENABLE_HUSH_IF
[RES_IF ] = "IF" ,
[RES_THEN ] = "THEN" ,
[RES_ELIF ] = "ELIF" ,
[RES_ELSE ] = "ELSE" ,
[RES_FI ] = "FI" ,
#endif
#if ENABLE_HUSH_LOOPS
[RES_FOR ] = "FOR" ,
[RES_WHILE] = "WHILE",
[RES_UNTIL] = "UNTIL",
[RES_DO ] = "DO" ,
[RES_DONE ] = "DONE" ,
[RES_IN ] = "IN" ,
#endif
[RES_XXXX ] = "XXXX" ,
[RES_SNTX ] = "SNTX" ,
};
int pin, prn;
pin = 0;
while (pi) {
fprintf(stderr, "%*spipe %d res_word=%s followup=%d %s\n", lvl*2, "",
pin, RES[pi->res_word], pi->followup, PIPE[pi->followup]);
prn = 0;
while (prn < pi->num_progs) {
struct child_prog *child = &pi->progs[prn];
char **argv = child->argv;
fprintf(stderr, "%*s prog %d", lvl*2, "", prn);
if (child->group) {
fprintf(stderr, " group %s: (argv=%p)\n",
(child->subshell ? "()" : "{}"),
argv);
debug_print_tree(child->group, lvl+1);
prn++;
continue;
}
if (argv) while (*argv) {
fprintf(stderr, " '%s'", *argv);
argv++;
}
fprintf(stderr, "\n");
prn++;
}
pi = pi->next;
pin++;
}
}
#endif
/* NB: called by pseudo_exec, and therefore must not modify any
* global data until exec/_exit (we can be a child after vfork!) */
static int run_list(struct pipe *pi)
{
struct pipe *rpipe;
#if ENABLE_HUSH_LOOPS
char *for_varname = NULL;
char **for_lcur = NULL;
char **for_list = NULL;
int flag_rep = 0;
#endif
int flag_skip = 1;
int rcode = 0; /* probably for gcc only */
int flag_restore = 0;
#if ENABLE_HUSH_IF
int if_code = 0, next_if_code = 0; /* need double-buffer to handle elif */
#else
enum { if_code = 0, next_if_code = 0 };
#endif
reserved_style rword IF_HAS_NO_KEYWORDS(= RES_NONE);
reserved_style skip_more_for_this_rword = RES_XXXX;
debug_printf_exec("run_list start lvl %d\n", run_list_level + 1);
#if ENABLE_HUSH_LOOPS
/* check syntax for "for" */
for (rpipe = pi; rpipe; rpipe = rpipe->next) {
if ((rpipe->res_word == RES_IN || rpipe->res_word == RES_FOR)
&& (rpipe->next == NULL)
) {
syntax("malformed for"); /* no IN or no commands after IN */
debug_printf_exec("run_list lvl %d return 1\n", run_list_level);
return 1;
}
if ((rpipe->res_word == RES_IN && rpipe->next->res_word == RES_IN && rpipe->next->progs[0].argv != NULL)
|| (rpipe->res_word == RES_FOR && rpipe->next->res_word != RES_IN)
) {
/* TODO: what is tested in the first condition? */
syntax("malformed for"); /* 2nd condition: FOR not followed by IN */
debug_printf_exec("run_list lvl %d return 1\n", run_list_level);
return 1;
}
}
#else
rpipe = NULL;
#endif
#if ENABLE_HUSH_JOB
/* Example of nested list: "while true; do { sleep 1 | exit 2; } done".
* We are saving state before entering outermost list ("while...done")
* so that ctrl-Z will correctly background _entire_ outermost list,
* not just a part of it (like "sleep 1 | exit 2") */
if (++run_list_level == 1 && interactive_fd) {
if (sigsetjmp(toplevel_jb, 1)) {
/* ctrl-Z forked and we are parent; or ctrl-C.
* Sighandler has longjmped us here */
signal(SIGINT, SIG_IGN);
signal(SIGTSTP, SIG_IGN);
/* Restore level (we can be coming from deep inside
* nested levels) */
run_list_level = 1;
#if ENABLE_FEATURE_SH_STANDALONE
if (nofork_save.saved) { /* if save area is valid */
debug_printf_jobs("exiting nofork early\n");
restore_nofork_data(&nofork_save);
}
#endif
if (ctrl_z_flag) {
/* ctrl-Z has forked and stored pid of the child in pi->pid.
* Remember this child as background job */
insert_bg_job(pi);
} else {
/* ctrl-C. We just stop doing whatever we were doing */
bb_putchar('\n');
}
rcode = 0;
goto ret;
}
/* ctrl-Z handler will store pid etc in pi */
toplevel_list = pi;
ctrl_z_flag = 0;
#if ENABLE_FEATURE_SH_STANDALONE
nofork_save.saved = 0; /* in case we will run a nofork later */
#endif
signal_SA_RESTART_empty_mask(SIGTSTP, handler_ctrl_z);
signal(SIGINT, handler_ctrl_c);
}
#endif /* JOB */
for (; pi; pi = flag_restore ? rpipe : pi->next) {
IF_HAS_KEYWORDS(rword = pi->res_word;)
IF_HAS_NO_KEYWORDS(rword = RES_NONE;)
#if ENABLE_HUSH_LOOPS
if (rword == RES_WHILE || rword == RES_UNTIL || rword == RES_FOR) {
flag_restore = 0;
if (!rpipe) {
flag_rep = 0;
rpipe = pi;
}
}
#endif
debug_printf_exec(": rword=%d if_code=%d next_if_code=%d skip_more=%d\n",
rword, if_code, next_if_code, skip_more_for_this_rword);
if (rword == skip_more_for_this_rword && flag_skip) {
if (pi->followup == PIPE_SEQ)
flag_skip = 0;
continue;
}
flag_skip = 1;
skip_more_for_this_rword = RES_XXXX;
#if ENABLE_HUSH_IF
if (rword == RES_THEN || rword == RES_ELSE)
if_code = next_if_code;
if (rword == RES_THEN && if_code)
continue;
if (rword == RES_ELSE && !if_code)
continue;
if (rword == RES_ELIF && !if_code)
break;
#endif
#if ENABLE_HUSH_LOOPS
if (rword == RES_FOR && pi->num_progs) {
if (!for_lcur) {
/* first loop through for */
/* if no variable values after "in" we skip "for" */
if (!pi->next->progs->argv)
continue;
/* create list of variable values */
debug_print_strings("for_list made from", pi->next->progs->argv);
for_list = expand_strvec_to_strvec(pi->next->progs->argv);
debug_print_strings("for_list", for_list);
for_lcur = for_list;
for_varname = pi->progs->argv[0];
pi->progs->argv[0] = NULL;
flag_rep = 1;
}
free(pi->progs->argv[0]);
if (!*for_lcur) {
/* for loop is over, clean up */
free(for_list);
for_lcur = NULL;
flag_rep = 0;
pi->progs->argv[0] = for_varname;
continue;
}
/* insert next value from for_lcur */
/* vda: does it need escaping? */
pi->progs->argv[0] = xasprintf("%s=%s", for_varname, *for_lcur++);
}
if (rword == RES_IN)
continue;
if (rword == RES_DO) {
if (!flag_rep)
continue;
}
if (rword == RES_DONE) {
if (flag_rep) {
flag_restore = 1;
} else {
rpipe = NULL;
}
}
#endif
if (pi->num_progs == 0)
continue;
debug_printf_exec(": run_pipe with %d members\n", pi->num_progs);
rcode = run_pipe(pi);
if (rcode != -1) {
/* We only ran a builtin: rcode was set by the return value
* of run_pipe(), and we don't need to wait for anything. */
} else if (pi->followup == PIPE_BG) {
/* What does bash do with attempts to background builtins? */
/* Even bash 3.2 doesn't do that well with nested bg:
* try "{ { sleep 10; echo DEEP; } & echo HERE; } &".
* I'm NOT treating inner &'s as jobs */
#if ENABLE_HUSH_JOB
if (run_list_level == 1)
insert_bg_job(pi);
#endif
rcode = EXIT_SUCCESS;
} else {
#if ENABLE_HUSH_JOB
if (run_list_level == 1 && interactive_fd) {
/* waits for completion, then fg's main shell */
rcode = checkjobs_and_fg_shell(pi);
} else
#endif
{
/* this one just waits for completion */
rcode = checkjobs(pi);
}
debug_printf_exec(": checkjobs returned %d\n", rcode);
}
debug_printf_exec(": setting last_return_code=%d\n", rcode);
last_return_code = rcode;
#if ENABLE_HUSH_IF
if (rword == RES_IF || rword == RES_ELIF)
next_if_code = rcode; /* can be overwritten a number of times */
#endif
#if ENABLE_HUSH_LOOPS
if (rword == RES_WHILE)
flag_rep = !last_return_code;
if (rword == RES_UNTIL)
flag_rep = last_return_code;
#endif
if ((rcode == EXIT_SUCCESS && pi->followup == PIPE_OR)
|| (rcode != EXIT_SUCCESS && pi->followup == PIPE_AND)
) {
skip_more_for_this_rword = rword;
}
checkjobs(NULL);
}
#if ENABLE_HUSH_JOB
if (ctrl_z_flag) {
/* ctrl-Z forked somewhere in the past, we are the child,
* and now we completed running the list. Exit. */
exit(rcode);
}
ret:
if (!--run_list_level && interactive_fd) {
signal(SIGTSTP, SIG_IGN);
signal(SIGINT, SIG_IGN);
}
#endif
debug_printf_exec("run_list lvl %d return %d\n", run_list_level + 1, rcode);
return rcode;
}
/* return code is the exit status of the pipe */
static int free_pipe(struct pipe *pi, int indent)
{
char **p;
struct child_prog *child;
struct redir_struct *r, *rnext;
int a, i, ret_code = 0;
if (pi->stopped_progs > 0)
return ret_code;
debug_printf_clean("%s run pipe: (pid %d)\n", indenter(indent), getpid());
for (i = 0; i < pi->num_progs; i++) {
child = &pi->progs[i];
debug_printf_clean("%s command %d:\n", indenter(indent), i);
if (child->argv) {
for (a = 0, p = child->argv; *p; a++, p++) {
debug_printf_clean("%s argv[%d] = %s\n", indenter(indent), a, *p);
}
free_strings(child->argv);
child->argv = NULL;
} else if (child->group) {
debug_printf_clean("%s begin group (subshell:%d)\n", indenter(indent), child->subshell);
ret_code = free_pipe_list(child->group, indent+3);
debug_printf_clean("%s end group\n", indenter(indent));
} else {
debug_printf_clean("%s (nil)\n", indenter(indent));
}
for (r = child->redirects; r; r = rnext) {
debug_printf_clean("%s redirect %d%s", indenter(indent), r->fd, redir_table[r->rd_type].descrip);
if (r->dup == -1) {
/* guard against the case >$FOO, where foo is unset or blank */
if (r->rd_filename) {
debug_printf_clean(" %s\n", r->rd_filename);
free(r->rd_filename);
r->rd_filename = NULL;
}
} else {
debug_printf_clean("&%d\n", r->dup);
}
rnext = r->next;
free(r);
}
child->redirects = NULL;
}
free(pi->progs); /* children are an array, they get freed all at once */
pi->progs = NULL;
#if ENABLE_HUSH_JOB
free(pi->cmdtext);
pi->cmdtext = NULL;
#endif
return ret_code;
}
static int free_pipe_list(struct pipe *head, int indent)
{
int rcode = 0; /* if list has no members */
struct pipe *pi, *next;
for (pi = head; pi; pi = next) {
#if HAS_KEYWORDS
debug_printf_clean("%s pipe reserved mode %d\n", indenter(indent), pi->res_word);
#endif
rcode = free_pipe(pi, indent);
debug_printf_clean("%s pipe followup code %d\n", indenter(indent), pi->followup);
next = pi->next;
/*pi->next = NULL;*/
free(pi);
}
return rcode;
}
/* Select which version we will use */
static int run_and_free_list(struct pipe *pi)
{
int rcode = 0;
debug_printf_exec("run_and_free_list entered\n");
if (!fake_mode) {
debug_printf_exec(": run_list with %d members\n", pi->num_progs);
rcode = run_list(pi);
}
/* free_pipe_list has the side effect of clearing memory.
* In the long run that function can be merged with run_list,
* but doing that now would hobble the debugging effort. */
free_pipe_list(pi, /* indent: */ 0);
debug_printf_exec("run_and_free_list return %d\n", rcode);
return rcode;
}
/* expand_strvec_to_strvec() takes a list of strings, expands
* all variable references within and returns a pointer to
* a list of expanded strings, possibly with larger number
* of strings. (Think VAR="a b"; echo $VAR).
* This new list is allocated as a single malloc block.
* NULL-terminated list of char* pointers is at the beginning of it,
* followed by strings themself.
* Caller can deallocate entire list by single free(list). */
/* Store given string, finalizing the word and starting new one whenever
* we encounter ifs char(s). This is used for expanding variable values.
* End-of-string does NOT finalize word: think about 'echo -$VAR-' */
static int expand_on_ifs(o_string *output, int n, const char *str)
{
while (1) {
int word_len = strcspn(str, ifs);
if (word_len) {
if (output->o_quote || !output->o_glob)
o_addQstr(output, str, word_len);
else /* protect backslashes against globbing up :) */
o_addstr_duplicate_backslash(output, str, word_len);
str += word_len;
}
if (!*str) /* EOL - do not finalize word */
break;
o_addchr(output, '\0');
debug_print_list("expand_on_ifs", output, n);
n = o_save_ptr(output, n);
str += strspn(str, ifs); /* skip ifs chars */
}
debug_print_list("expand_on_ifs[1]", output, n);
return n;
}
/* Expand all variable references in given string, adding words to list[]
* at n, n+1,... positions. Return updated n (so that list[n] is next one
* to be filled). This routine is extremely tricky: has to deal with
* variables/parameters with whitespace, $* and $@, and constructs like
* 'echo -$*-'. If you play here, you must run testsuite afterwards! */
/* NB: another bug is that we cannot detect empty strings yet:
* "" or $empty"" expands to zero words, has to expand to empty word */
static int expand_vars_to_list(o_string *output, int n, char *arg, char or_mask)
{
/* or_mask is either 0 (normal case) or 0x80
* (expansion of right-hand side of assignment == 1-element expand.
* It will also do no globbing, and thus we must not backslash-quote!) */
char first_ch, ored_ch;
int i;
const char *val;
char *p;
ored_ch = 0;
debug_printf_expand("expand_vars_to_list: arg '%s'\n", arg);
debug_print_list("expand_vars_to_list", output, n);
n = o_save_ptr(output, n);
debug_print_list("expand_vars_to_list[0]", output, n);
while ((p = strchr(arg, SPECIAL_VAR_SYMBOL)) != NULL) {
#if ENABLE_HUSH_TICK
o_string subst_result = NULL_O_STRING;
#endif
o_addstr(output, arg, p - arg);
debug_print_list("expand_vars_to_list[1]", output, n);
arg = ++p;
p = strchr(p, SPECIAL_VAR_SYMBOL);
first_ch = arg[0] | or_mask; /* forced to "quoted" if or_mask = 0x80 */
ored_ch |= first_ch;
val = NULL;
switch (first_ch & 0x7f) {
/* Highest bit in first_ch indicates that var is double-quoted */
case '$': /* pid */
val = utoa(root_pid);
break;
case '!': /* bg pid */
val = last_bg_pid ? utoa(last_bg_pid) : (char*)"";
break;
case '?': /* exitcode */
val = utoa(last_return_code);
break;
case '#': /* argc */
val = utoa(global_argc ? global_argc-1 : 0);
break;
case '*':
case '@':
i = 1;
if (!global_argv[i])
break;
if (!(first_ch & 0x80)) { /* unquoted $* or $@ */
smallint sv = output->o_quote;
/* unquoted var's contents should be globbed, so don't quote */
output->o_quote = 0;
while (global_argv[i]) {
n = expand_on_ifs(output, n, global_argv[i]);
debug_printf_expand("expand_vars_to_list: argv %d (last %d)\n", i, global_argc-1);
if (global_argv[i++][0] && global_argv[i]) {
/* this argv[] is not empty and not last:
* put terminating NUL, start new word */
o_addchr(output, '\0');
debug_print_list("expand_vars_to_list[2]", output, n);
n = o_save_ptr(output, n);
debug_print_list("expand_vars_to_list[3]", output, n);
}
}
output->o_quote = sv;
} else
/* If or_mask is nonzero, we handle assignment 'a=....$@.....'
* and in this case should treat it like '$*' - see 'else...' below */
if (first_ch == ('@'|0x80) && !or_mask) { /* quoted $@ */
while (1) {
o_addQstr(output, global_argv[i], strlen(global_argv[i]));
if (++i >= global_argc)
break;
o_addchr(output, '\0');
debug_print_list("expand_vars_to_list[4]", output, n);
n = o_save_ptr(output, n);
}
} else { /* quoted $*: add as one word */
while (1) {
o_addQstr(output, global_argv[i], strlen(global_argv[i]));
if (!global_argv[++i])
break;
if (ifs[0])
o_addchr(output, ifs[0]);
}
}
break;
case SPECIAL_VAR_SYMBOL: /* <SPECIAL_VAR_SYMBOL><SPECIAL_VAR_SYMBOL> */
/* "Empty variable", used to make "" etc to not disappear */
arg++;
ored_ch = 0x80;
break;
#if ENABLE_HUSH_TICK
case '`': { /* <SPECIAL_VAR_SYMBOL>`cmd<SPECIAL_VAR_SYMBOL> */
struct in_str input;
*p = '\0';
arg++;
//TODO: can we just stuff it into "output" directly?
debug_printf_subst("SUBST '%s' first_ch %x\n", arg, first_ch);
setup_string_in_str(&input, arg);
process_command_subs(&subst_result, &input, NULL);
debug_printf_subst("SUBST RES '%s'\n", subst_result.data);
val = subst_result.data;
goto store_val;
}
#endif
default: /* <SPECIAL_VAR_SYMBOL>varname<SPECIAL_VAR_SYMBOL> */
*p = '\0';
arg[0] = first_ch & 0x7f;
if (isdigit(arg[0])) {
i = xatoi_u(arg);
if (i < global_argc)
val = global_argv[i];
/* else val remains NULL: $N with too big N */
} else
val = lookup_param(arg);
arg[0] = first_ch;
#if ENABLE_HUSH_TICK
store_val:
#endif
*p = SPECIAL_VAR_SYMBOL;
if (!(first_ch & 0x80)) { /* unquoted $VAR */
debug_printf_expand("unquoted '%s', output->o_quote:%d\n", val, output->o_quote);
if (val) {
/* unquoted var's contents should be globbed, so don't quote */
smallint sv = output->o_quote;
output->o_quote = 0;
n = expand_on_ifs(output, n, val);
val = NULL;
output->o_quote = sv;
}
} else { /* quoted $VAR, val will be appended below */
debug_printf_expand("quoted '%s', output->o_quote:%d\n", val, output->o_quote);
}
}
if (val) {
o_addQstr(output, val, strlen(val));
}
#if ENABLE_HUSH_TICK
o_free(&subst_result);
#endif
arg = ++p;
} /* end of "while (SPECIAL_VAR_SYMBOL is found) ..." */
if (arg[0]) {
debug_print_list("expand_vars_to_list[a]", output, n);
/* this part is literal, and it was already pre-quoted
* if needed (much earlier), do not use o_addQstr here! */
o_addstr(output, arg, strlen(arg) + 1);
debug_print_list("expand_vars_to_list[b]", output, n);
} else if (output->length == o_get_last_ptr(output, n) /* expansion is empty */
&& !(ored_ch & 0x80) /* and all vars were not quoted. */
) {
n--;
/* allow to reuse list[n] later without re-growth */
output->has_empty_slot = 1;
} else {
o_addchr(output, '\0');
}
return n;
}
static char **expand_variables(char **argv, int or_mask)
{
int n;
char **list;
char **v;
o_string output = NULL_O_STRING;
if (or_mask & 0x100) {
output.o_quote = 1; /* protect against globbing for "$var" */
/* (unquoted $var will temporarily switch it off) */
output.o_glob = 1;
}
n = 0;
v = argv;
while (*v) {
n = expand_vars_to_list(&output, n, *v, (char)or_mask);
v++;
}
debug_print_list("expand_variables", &output, n);
/* output.data (malloced in one block) gets returned in "list" */
list = o_finalize_list(&output, n);
debug_print_strings("expand_variables[1]", list);
return list;
}
static char **expand_strvec_to_strvec(char **argv)
{
return expand_variables(argv, 0x100);
}
/* Used for expansion of right hand of assignments */
/* NB: should NOT do globbing! "export v=/bin/c*; env | grep ^v=" outputs
* "v=/bin/c*" */
static char *expand_string_to_string(const char *str)
{
char *argv[2], **list;
argv[0] = (char*)str;
argv[1] = NULL;
list = expand_variables(argv, 0x80); /* 0x80: make one-element expansion */
if (HUSH_DEBUG)
if (!list[0] || list[1])
bb_error_msg_and_die("BUG in varexp2");
/* actually, just move string 2*sizeof(char*) bytes back */
strcpy((char*)list, list[0]);
debug_printf_expand("string_to_string='%s'\n", (char*)list);
return (char*)list;
}
/* Used for "eval" builtin */
static char* expand_strvec_to_string(char **argv)
{
char **list;
list = expand_variables(argv, 0x80);
/* Convert all NULs to spaces */
if (list[0]) {
int n = 1;
while (list[n]) {
if (HUSH_DEBUG)
if (list[n-1] + strlen(list[n-1]) + 1 != list[n])
bb_error_msg_and_die("BUG in varexp3");
list[n][-1] = ' '; /* TODO: or to ifs[0]? */
n++;
}
}
strcpy((char*)list, list[0]);
debug_printf_expand("strvec_to_string='%s'\n", (char*)list);
return (char*)list;
}
/* Used to get/check local shell variables */
static struct variable *get_local_var(const char *name)
{
struct variable *cur;
int len;
if (!name)
return NULL;
len = strlen(name);
for (cur = top_var; cur; cur = cur->next) {
if (strncmp(cur->varstr, name, len) == 0 && cur->varstr[len] == '=')
return cur;
}
return NULL;
}
/* str holds "NAME=VAL" and is expected to be malloced.
* We take ownership of it. */
static int set_local_var(char *str, int flg_export)
{
struct variable *cur;
char *value;
int name_len;
value = strchr(str, '=');
if (!value) { /* not expected to ever happen? */
free(str);
return -1;
}
name_len = value - str + 1; /* including '=' */
cur = top_var; /* cannot be NULL (we have HUSH_VERSION and it's RO) */
while (1) {
if (strncmp(cur->varstr, str, name_len) != 0) {
if (!cur->next) {
/* Bail out. Note that now cur points
* to last var in linked list */
break;
}
cur = cur->next;
continue;
}
/* We found an existing var with this name */
*value = '\0';
if (cur->flg_read_only) {
bb_error_msg("%s: readonly variable", str);
free(str);
return -1;
}
unsetenv(str); /* just in case */
*value = '=';
if (strcmp(cur->varstr, str) == 0) {
free_and_exp:
free(str);
goto exp;
}
if (cur->max_len >= strlen(str)) {
/* This one is from startup env, reuse space */
strcpy(cur->varstr, str);
goto free_and_exp;
}
/* max_len == 0 signifies "malloced" var, which we can
* (and has to) free */
if (!cur->max_len)
free(cur->varstr);
cur->max_len = 0;
goto set_str_and_exp;
}
/* Not found - create next variable struct */
cur->next = xzalloc(sizeof(*cur));
cur = cur->next;
set_str_and_exp:
cur->varstr = str;
exp:
if (flg_export)
cur->flg_export = 1;
if (cur->flg_export)
return putenv(cur->varstr);
return 0;
}
static void unset_local_var(const char *name)
{
struct variable *cur;
struct variable *prev = prev; /* for gcc */
int name_len;
if (!name)
return;
name_len = strlen(name);
cur = top_var;
while (cur) {
if (strncmp(cur->varstr, name, name_len) == 0 && cur->varstr[name_len] == '=') {
if (cur->flg_read_only) {
bb_error_msg("%s: readonly variable", name);
return;
}
/* prev is ok to use here because 1st variable, HUSH_VERSION,
* is ro, and we cannot reach this code on the 1st pass */
prev->next = cur->next;
unsetenv(cur->varstr);
if (!cur->max_len)
free(cur->varstr);
free(cur);
return;
}
prev = cur;
cur = cur->next;
}
}
/* the src parameter allows us to peek forward to a possible &n syntax
* for file descriptor duplication, e.g., "2>&1".
* Return code is 0 normally, 1 if a syntax error is detected in src.
* Resource errors (in xmalloc) cause the process to exit */
static int setup_redirect(struct p_context *ctx, int fd, redir_type style,
struct in_str *input)
{
struct child_prog *child = ctx->child;
struct redir_struct *redir = child->redirects;
struct redir_struct *last_redir = NULL;
/* Create a new redir_struct and drop it onto the end of the linked list */
while (redir) {
last_redir = redir;
redir = redir->next;
}
redir = xzalloc(sizeof(struct redir_struct));
/* redir->next = NULL; */
/* redir->rd_filename = NULL; */
if (last_redir) {
last_redir->next = redir;
} else {
child->redirects = redir;
}
redir->rd_type = style;
redir->fd = (fd == -1) ? redir_table[style].default_fd : fd;
debug_printf("Redirect type %d%s\n", redir->fd, redir_table[style].descrip);
/* Check for a '2>&1' type redirect */
redir->dup = redirect_dup_num(input);
if (redir->dup == -2)
return 1; /* syntax error */
if (redir->dup != -1) {
/* Erik had a check here that the file descriptor in question
* is legit; I postpone that to "run time"
* A "-" representation of "close me" shows up as a -3 here */
debug_printf("Duplicating redirect '%d>&%d'\n", redir->fd, redir->dup);
} else {
/* We do _not_ try to open the file that src points to,
* since we need to return and let src be expanded first.
* Set ctx->pending_redirect, so we know what to do at the
* end of the next parsed word. */
ctx->pending_redirect = redir;
}
return 0;
}
static struct pipe *new_pipe(void)
{
struct pipe *pi;
pi = xzalloc(sizeof(struct pipe));
/*pi->followup = 0; - deliberately invalid value */
/*pi->res_word = RES_NONE; - RES_NONE is 0 anyway */
return pi;
}
static void initialize_context(struct p_context *ctx)
{
memset(ctx, 0, sizeof(*ctx));
ctx->pipe = ctx->list_head = new_pipe();
/* Create the memory for child, roughly:
* ctx->pipe->progs = new struct child_prog;
* ctx->pipe->progs[0].family = ctx->pipe;
* ctx->child = &ctx->pipe->progs[0];
*/
done_command(ctx);
}
/* If a reserved word is found and processed, parse context is modified
* and 1 is returned.
* Handles if, then, elif, else, fi, for, while, until, do, done.
* case, function, and select are obnoxious, save those for later.
*/
#if HAS_KEYWORDS
static int reserved_word(const o_string *word, struct p_context *ctx)
{
struct reserved_combo {
char literal[7];
unsigned char res;
int flag;
};
enum {
FLAG_END = (1 << RES_NONE ),
#if ENABLE_HUSH_IF
FLAG_IF = (1 << RES_IF ),
FLAG_THEN = (1 << RES_THEN ),
FLAG_ELIF = (1 << RES_ELIF ),
FLAG_ELSE = (1 << RES_ELSE ),
FLAG_FI = (1 << RES_FI ),
#endif
#if ENABLE_HUSH_LOOPS
FLAG_FOR = (1 << RES_FOR ),
FLAG_WHILE = (1 << RES_WHILE),
FLAG_UNTIL = (1 << RES_UNTIL),
FLAG_DO = (1 << RES_DO ),
FLAG_DONE = (1 << RES_DONE ),
FLAG_IN = (1 << RES_IN ),
#endif
FLAG_START = (1 << RES_XXXX ),
};
/* Mostly a list of accepted follow-up reserved words.
* FLAG_END means we are done with the sequence, and are ready
* to turn the compound list into a command.
* FLAG_START means the word must start a new compound list.
*/
static const struct reserved_combo reserved_list[] = {
#if ENABLE_HUSH_IF
{ "!", RES_NONE, 0 },
{ "if", RES_IF, FLAG_THEN | FLAG_START },
{ "then", RES_THEN, FLAG_ELIF | FLAG_ELSE | FLAG_FI },
{ "elif", RES_ELIF, FLAG_THEN },
{ "else", RES_ELSE, FLAG_FI },
{ "fi", RES_FI, FLAG_END },
#endif
#if ENABLE_HUSH_LOOPS
{ "for", RES_FOR, FLAG_IN | FLAG_START },
{ "while", RES_WHILE, FLAG_DO | FLAG_START },
{ "until", RES_UNTIL, FLAG_DO | FLAG_START },
{ "in", RES_IN, FLAG_DO },
{ "do", RES_DO, FLAG_DONE },
{ "done", RES_DONE, FLAG_END }
#endif
};
const struct reserved_combo *r;
for (r = reserved_list; r < reserved_list + ARRAY_SIZE(reserved_list); r++) {
if (strcmp(word->data, r->literal) != 0)
continue;
debug_printf("found reserved word %s, res %d\n", r->literal, r->res);
if (r->flag == 0) { /* '!' */
#if ENABLE_HUSH_LOOPS
if (ctx->ctx_res_w == RES_IN) {
/* 'for a in ! a b c; ...' - ! isn't a keyword here */
break;
}
#endif
if (ctx->ctx_inverted /* bash doesn't accept '! ! true' */
#if ENABLE_HUSH_LOOPS
|| ctx->ctx_res_w == RES_FOR /* example: 'for ! a' */
#endif
) {
syntax(NULL);
IF_HAS_KEYWORDS(ctx->ctx_res_w = RES_SNTX;)
}
ctx->ctx_inverted = 1;
return 1;
}
if (r->flag & FLAG_START) {
struct p_context *new;
debug_printf("push stack\n");
#if ENABLE_HUSH_LOOPS
if (ctx->ctx_res_w == RES_IN || ctx->ctx_res_w == RES_FOR) {
syntax("malformed for"); /* example: 'for if' */
ctx->ctx_res_w = RES_SNTX;
return 1;
}
#endif
new = xmalloc(sizeof(*new));
*new = *ctx; /* physical copy */
initialize_context(ctx);
ctx->stack = new;
} else if (ctx->ctx_res_w == RES_NONE || !(ctx->old_flag & (1 << r->res))) {
syntax(NULL);
ctx->ctx_res_w = RES_SNTX;
return 1;
}
ctx->ctx_res_w = r->res;
ctx->old_flag = r->flag;
if (ctx->old_flag & FLAG_END) {
struct p_context *old;
debug_printf("pop stack\n");
done_pipe(ctx, PIPE_SEQ);
old = ctx->stack;
old->child->group = ctx->list_head;
old->child->subshell = 0;
*ctx = *old; /* physical copy */
free(old);
}
return 1;
}
return 0;
}
#endif
/* Word is complete, look at it and update parsing context.
* Normal return is 0. Syntax errors return 1. */
static int done_word(o_string *word, struct p_context *ctx)
{
struct child_prog *child = ctx->child;
/* If this word wasn't an assignment, next ones definitely
* can't be assignments. Even if they look like ones. */
if (word->o_assignment != DEFINITELY_ASSIGNMENT) {
word->o_assignment = NOT_ASSIGNMENT;
} else {
word->o_assignment = MAYBE_ASSIGNMENT;
}
debug_printf_parse("done_word entered: '%s' %p\n", word->data, child);
if (word->length == 0 && word->nonnull == 0) {
debug_printf_parse("done_word return 0: true null, ignored\n");
return 0;
}
if (ctx->pending_redirect) {
/* We do not glob in e.g. >*.tmp case. bash seems to glob here
* only if run as "bash", not "sh" */
ctx->pending_redirect->rd_filename = xstrdup(word->data);
word->o_assignment = NOT_ASSIGNMENT;
debug_printf("word stored in rd_filename: '%s'\n", word->data);
} else {
if (child->group) { /* TODO: example how to trigger? */
syntax(NULL);
debug_printf_parse("done_word return 1: syntax error, groups and arglists don't mix\n");
return 1;
}
#if HAS_KEYWORDS
if (!child->argv) { /* if it's the first word... */
debug_printf_parse(": checking '%s' for reserved-ness\n", word->data);
if (reserved_word(word, ctx)) {
o_reset(word);
word->o_assignment = NOT_ASSIGNMENT;
debug_printf_parse("done_word return %d\n", (ctx->ctx_res_w == RES_SNTX));
return (ctx->ctx_res_w == RES_SNTX);
}
}
#endif
if (word->nonnull /* we saw "xx" or 'xx' */
/* optimization: and if it's ("" or '') or ($v... or `cmd`...): */
&& (word->data[0] == '\0' || word->data[0] == SPECIAL_VAR_SYMBOL)
/* (otherwise it's "abc".... and is already safe) */
) {
/* Insert "empty variable" reference, this makes
* e.g. "", $empty"" etc to not disappear */
o_addchr(word, SPECIAL_VAR_SYMBOL);
o_addchr(word, SPECIAL_VAR_SYMBOL);
}
child->argv = add_malloced_string_to_strings(child->argv, xstrdup(word->data));
debug_print_strings("word appended to argv", child->argv);
}
o_reset(word);
ctx->pending_redirect = NULL;
#if ENABLE_HUSH_LOOPS
/* Force FOR to have just one word (variable name) */
if (ctx->ctx_res_w == RES_FOR)
done_pipe(ctx, PIPE_SEQ);
#endif
debug_printf_parse("done_word return 0\n");
return 0;
}
/* Command (member of a pipe) is complete. The only possible error here
* is out of memory, in which case xmalloc exits. */
static int done_command(struct p_context *ctx)
{
/* The child is really already in the pipe structure, so
* advance the pipe counter and make a new, null child. */
struct pipe *pi = ctx->pipe;
struct child_prog *child = ctx->child;
if (child) {
if (child->group == NULL
&& child->argv == NULL
&& child->redirects == NULL
) {
debug_printf_parse("done_command: skipping null cmd, num_progs=%d\n", pi->num_progs);
return pi->num_progs;
}
pi->num_progs++;
debug_printf_parse("done_command: ++num_progs=%d\n", pi->num_progs);
} else {
debug_printf_parse("done_command: initializing, num_progs=%d\n", pi->num_progs);
}
/* Only real trickiness here is that the uncommitted
* child structure is not counted in pi->num_progs. */
pi->progs = xrealloc(pi->progs, sizeof(*pi->progs) * (pi->num_progs+1));
child = &pi->progs[pi->num_progs];
memset(child, 0, sizeof(*child));
child->family = pi;
ctx->child = child;
/* but ctx->pipe and ctx->list_head remain unchanged */
return pi->num_progs; /* used only for 0/nonzero check */
}
static void done_pipe(struct p_context *ctx, pipe_style type)
{
int not_null;
debug_printf_parse("done_pipe entered, followup %d\n", type);
not_null = done_command(ctx); /* implicit closure of previous command */
ctx->pipe->followup = type;
IF_HAS_KEYWORDS(ctx->pipe->res_word = ctx->ctx_res_w;)
IF_HAS_KEYWORDS(ctx->pipe->pi_inverted = ctx->ctx_inverted;)
IF_HAS_KEYWORDS(ctx->ctx_inverted = 0;)
/* Without this check, even just <enter> on command line generates
* tree of three NOPs (!). Which is harmless but annoying.
* IOW: it is safe to do it unconditionally.
* RES_IN case is for "for a in; do ..." (empty IN set)
* to work. */
if (not_null USE_HUSH_LOOPS(|| ctx->pipe->res_word == RES_IN)) {
struct pipe *new_p = new_pipe();
ctx->pipe->next = new_p;
ctx->pipe = new_p;
ctx->child = NULL; /* needed! */
/* Create the memory for child, roughly:
* ctx->pipe->progs = new struct child_prog;
* ctx->pipe->progs[0].family = ctx->pipe;
* ctx->child = &ctx->pipe->progs[0];
*/
done_command(ctx);
}
debug_printf_parse("done_pipe return\n");
}
/* Peek ahead in the in_str to find out if we have a "&n" construct,
* as in "2>&1", that represents duplicating a file descriptor.
* Return either -2 (syntax error), -1 (no &), or the number found.
*/
static int redirect_dup_num(struct in_str *input)
{
int ch, d = 0, ok = 0;
ch = i_peek(input);
if (ch != '&') return -1;
i_getch(input); /* get the & */
ch = i_peek(input);
if (ch == '-') {
i_getch(input);
return -3; /* "-" represents "close me" */
}
while (isdigit(ch)) {
d = d*10 + (ch-'0');
ok = 1;
i_getch(input);
ch = i_peek(input);
}
if (ok) return d;
bb_error_msg("ambiguous redirect");
return -2;
}
/* If a redirect is immediately preceded by a number, that number is
* supposed to tell which file descriptor to redirect. This routine
* looks for such preceding numbers. In an ideal world this routine
* needs to handle all the following classes of redirects...
* echo 2>foo # redirects fd 2 to file "foo", nothing passed to echo
* echo 49>foo # redirects fd 49 to file "foo", nothing passed to echo
* echo -2>foo # redirects fd 1 to file "foo", "-2" passed to echo
* echo 49x>foo # redirects fd 1 to file "foo", "49x" passed to echo
* A -1 output from this program means no valid number was found, so the
* caller should use the appropriate default for this redirection.
*/
static int redirect_opt_num(o_string *o)
{
int num;
if (o->length == 0)
return -1;
for (num = 0; num < o->length; num++) {
if (!isdigit(o->data[num])) {
return -1;
}
}
num = atoi(o->data);
o_reset(o);
return num;
}
#if ENABLE_HUSH_TICK
static FILE *generate_stream_from_list(struct pipe *head)
{
FILE *pf;
int pid, channel[2];
xpipe(channel);
/* *** NOMMU WARNING *** */
/* By using vfork here, we suspend parent till child exits or execs.
* If child will not do it before it fills the pipe, it can block forever
* in write(STDOUT_FILENO), and parent (shell) will be also stuck.
* Try this script:
* yes "0123456789012345678901234567890" | dd bs=32 count=64k >TESTFILE
* huge=`cat TESTFILE` # will block here forever
* echo OK
*/
pid = BB_MMU ? fork() : vfork();
if (pid < 0)
bb_perror_msg_and_die(BB_MMU ? "fork" : "vfork");
if (pid == 0) { /* child */
if (ENABLE_HUSH_JOB)
die_sleep = 0; /* let nofork's xfuncs die */
close(channel[0]); /* NB: close _first_, then move fd! */
xmove_fd(channel[1], 1);
/* Prevent it from trying to handle ctrl-z etc */
#if ENABLE_HUSH_JOB
run_list_level = 1;
#endif
/* Process substitution is not considered to be usual
* 'command execution'.
* SUSv3 says ctrl-Z should be ignored, ctrl-C should not. */
/* Not needed, we are relying on it being disabled
* everywhere outside actual command execution. */
/*set_jobctrl_sighandler(SIG_IGN);*/
set_misc_sighandler(SIG_DFL);
/* Freeing 'head' here would break NOMMU. */
_exit(run_list(head));
}
close(channel[1]);
pf = fdopen(channel[0], "r");
return pf;
/* 'head' is freed by the caller */
}
/* Return code is exit status of the process that is run. */
static int process_command_subs(o_string *dest,
struct in_str *input,
const char *subst_end)
{
int retcode, ch, eol_cnt;
o_string result = NULL_O_STRING;
struct p_context inner;
FILE *p;
struct in_str pipe_str;
initialize_context(&inner);
/* Recursion to generate command */
retcode = parse_stream(&result, &inner, input, subst_end);
if (retcode != 0)
return retcode; /* syntax error or EOF */
done_word(&result, &inner);
done_pipe(&inner, PIPE_SEQ);
o_free(&result);
p = generate_stream_from_list(inner.list_head);
if (p == NULL)
return 1;
close_on_exec_on(fileno(p));
setup_file_in_str(&pipe_str, p);
/* Now send results of command back into original context */
eol_cnt = 0;
while ((ch = i_getch(&pipe_str)) != EOF) {
if (ch == '\n') {
eol_cnt++;
continue;
}
while (eol_cnt) {
o_addchr(dest, '\n');
eol_cnt--;
}
// /* Even unquoted `echo '\'` results in two backslashes
// * (which are converted into one by globbing later) */
// if (!dest->o_quote && ch == '\\') {
// o_addchr(dest, ch);
// }
o_addQchr(dest, ch);
}
debug_printf("done reading from pipe, pclose()ing\n");
/* This is the step that wait()s for the child. Should be pretty
* safe, since we just read an EOF from its stdout. We could try
* to do better, by using wait(), and keeping track of background jobs
* at the same time. That would be a lot of work, and contrary
* to the KISS philosophy of this program. */
retcode = fclose(p);
free_pipe_list(inner.list_head, /* indent: */ 0);
debug_printf("closed FILE from child, retcode=%d\n", retcode);
return retcode;
}
#endif
static int parse_group(o_string *dest, struct p_context *ctx,
struct in_str *input, int ch)
{
int rcode;
const char *endch = NULL;
struct p_context sub;
struct child_prog *child = ctx->child;
debug_printf_parse("parse_group entered\n");
if (child->argv) {
syntax(NULL);
debug_printf_parse("parse_group return 1: syntax error, groups and arglists don't mix\n");
return 1;
}
initialize_context(&sub);
endch = "}";
if (ch == '(') {
endch = ")";
child->subshell = 1;
}
rcode = parse_stream(dest, &sub, input, endch);
if (rcode == 0) {
done_word(dest, &sub); /* finish off the final word in the subcontext */
done_pipe(&sub, PIPE_SEQ); /* and the final command there, too */
child->group = sub.list_head;
}
debug_printf_parse("parse_group return %d\n", rcode);
return rcode;
/* child remains "open", available for possible redirects */
}
/* Basically useful version until someone wants to get fancier,
* see the bash man page under "Parameter Expansion" */
static const char *lookup_param(const char *src)
{
struct variable *var = get_local_var(src);
if (var)
return strchr(var->varstr, '=') + 1;
return NULL;
}
#if ENABLE_HUSH_TICK
/* Subroutines for copying $(...) and `...` things */
static void add_till_backquote(o_string *dest, struct in_str *input);
/* '...' */
static void add_till_single_quote(o_string *dest, struct in_str *input)
{
while (1) {
int ch = i_getch(input);
if (ch == EOF)
break;
if (ch == '\'')
break;
o_addchr(dest, ch);
}
}
/* "...\"...`..`...." - do we need to handle "...$(..)..." too? */
static void add_till_double_quote(o_string *dest, struct in_str *input)
{
while (1) {
int ch = i_getch(input);
if (ch == '"')
break;
if (ch == '\\') { /* \x. Copy both chars. */
o_addchr(dest, ch);
ch = i_getch(input);
}
if (ch == EOF)
break;
o_addchr(dest, ch);
if (ch == '`') {
add_till_backquote(dest, input);
o_addchr(dest, ch);
continue;
}
//if (ch == '$') ...
}
}
/* Process `cmd` - copy contents until "`" is seen. Complicated by
* \` quoting.
* "Within the backquoted style of command substitution, backslash
* shall retain its literal meaning, except when followed by: '$', '`', or '\'.
* The search for the matching backquote shall be satisfied by the first
* backquote found without a preceding backslash; during this search,
* if a non-escaped backquote is encountered within a shell comment,
* a here-document, an embedded command substitution of the $(command)
* form, or a quoted string, undefined results occur. A single-quoted
* or double-quoted string that begins, but does not end, within the
* "`...`" sequence produces undefined results."
* Example Output
* echo `echo '\'TEST\`echo ZZ\`BEST` \TESTZZBEST
*/
static void add_till_backquote(o_string *dest, struct in_str *input)
{
while (1) {
int ch = i_getch(input);
if (ch == '`')
break;
if (ch == '\\') { /* \x. Copy both chars unless it is \` */
int ch2 = i_getch(input);
if (ch2 != '`' && ch2 != '$' && ch2 != '\\')
o_addchr(dest, ch);
ch = ch2;
}
if (ch == EOF)
break;
o_addchr(dest, ch);
}
}
/* Process $(cmd) - copy contents until ")" is seen. Complicated by
* quoting and nested ()s.
* "With the $(command) style of command substitution, all characters
* following the open parenthesis to the matching closing parenthesis
* constitute the command. Any valid shell script can be used for command,
* except a script consisting solely of redirections which produces
* unspecified results."
* Example Output
* echo $(echo '(TEST)' BEST) (TEST) BEST
* echo $(echo 'TEST)' BEST) TEST) BEST
* echo $(echo \(\(TEST\) BEST) ((TEST) BEST
*/
static void add_till_closing_curly_brace(o_string *dest, struct in_str *input)
{
int count = 0;
while (1) {
int ch = i_getch(input);
if (ch == EOF)
break;
if (ch == '(')
count++;
if (ch == ')')
if (--count < 0)
break;
o_addchr(dest, ch);
if (ch == '\'') {
add_till_single_quote(dest, input);
o_addchr(dest, ch);
continue;
}
if (ch == '"') {
add_till_double_quote(dest, input);
o_addchr(dest, ch);
continue;
}
if (ch == '\\') { /* \x. Copy verbatim. Important for \(, \) */
ch = i_getch(input);
if (ch == EOF)
break;
o_addchr(dest, ch);
continue;
}
}
}
#endif /* ENABLE_HUSH_TICK */
/* Return code: 0 for OK, 1 for syntax error */
static int handle_dollar(o_string *dest, struct in_str *input)
{
int ch = i_peek(input); /* first character after the $ */
unsigned char quote_mask = dest->o_quote ? 0x80 : 0;
debug_printf_parse("handle_dollar entered: ch='%c'\n", ch);
if (isalpha(ch)) {
o_addchr(dest, SPECIAL_VAR_SYMBOL);
while (1) {
debug_printf_parse(": '%c'\n", ch);
i_getch(input);
o_addchr(dest, ch | quote_mask);
quote_mask = 0;
ch = i_peek(input);
if (!isalnum(ch) && ch != '_')
break;
}
o_addchr(dest, SPECIAL_VAR_SYMBOL);
} else if (isdigit(ch)) {
make_one_char_var:
o_addchr(dest, SPECIAL_VAR_SYMBOL);
debug_printf_parse(": '%c'\n", ch);
i_getch(input);
o_addchr(dest, ch | quote_mask);
o_addchr(dest, SPECIAL_VAR_SYMBOL);
} else switch (ch) {
case '$': /* pid */
case '!': /* last bg pid */
case '?': /* last exit code */
case '#': /* number of args */
case '*': /* args */
case '@': /* args */
goto make_one_char_var;
case '{':
o_addchr(dest, SPECIAL_VAR_SYMBOL);
i_getch(input);
/* XXX maybe someone will try to escape the '}' */
while (1) {
ch = i_getch(input);
if (ch == '}')
break;
if (!isalnum(ch) && ch != '_') {
syntax("unterminated ${name}");
debug_printf_parse("handle_dollar return 1: unterminated ${name}\n");
return 1;
}
debug_printf_parse(": '%c'\n", ch);
o_addchr(dest, ch | quote_mask);
quote_mask = 0;
}
o_addchr(dest, SPECIAL_VAR_SYMBOL);
break;
#if ENABLE_HUSH_TICK
case '(': {
//int pos = dest->length;
i_getch(input);
o_addchr(dest, SPECIAL_VAR_SYMBOL);
o_addchr(dest, quote_mask | '`');
add_till_closing_curly_brace(dest, input);
//debug_printf_subst("SUBST RES2 '%s'\n", dest->data + pos);
o_addchr(dest, SPECIAL_VAR_SYMBOL);
break;
}
#endif
case '-':
case '_':
/* still unhandled, but should be eventually */
bb_error_msg("unhandled syntax: $%c", ch);
return 1;
break;
default:
o_addQchr(dest, '$');
}
debug_printf_parse("handle_dollar return 0\n");
return 0;
}
/* Scan input, call done_word() whenever full IFS delemited word was seen.
* call done_pipe if '\n' was seen (and end_trigger != NULL)
* Return if (non-quoted) char in end_trigger was seen; or on parse error. */
/* Return code is 0 if end_trigger char is met,
* -1 on EOF (but if end_trigger == NULL then return 0)
* 1 for syntax error */
static int parse_stream(o_string *dest, struct p_context *ctx,
struct in_str *input, const char *end_trigger)
{
int ch, m;
int redir_fd;
redir_type redir_style;
int shadow_quote = dest->o_quote;
int next;
/* Only double-quote state is handled in the state variable dest->o_quote.
* A single-quote triggers a bypass of the main loop until its mate is
* found. When recursing, quote state is passed in via dest->o_quote. */
debug_printf_parse("parse_stream entered, end_trigger='%s'\n", end_trigger);
while (1) {
m = CHAR_IFS;
next = '\0';
ch = i_getch(input);
if (ch != EOF) {
m = charmap[ch];
if (ch != '\n') {
next = i_peek(input);
}
}
debug_printf_parse(": ch=%c (%d) m=%d quote=%d\n",
ch, ch, m, dest->o_quote);
if (m == CHAR_ORDINARY
|| (m != CHAR_SPECIAL && shadow_quote)
) {
if (ch == EOF) {
syntax("unterminated \"");
debug_printf_parse("parse_stream return 1: unterminated \"\n");
return 1;
}
o_addQchr(dest, ch);
if (dest->o_assignment == MAYBE_ASSIGNMENT
&& ch == '='
&& is_assignment(dest->data)
) {
dest->o_assignment = DEFINITELY_ASSIGNMENT;
}
continue;
}
if (m == CHAR_IFS) {
if (done_word(dest, ctx)) {
debug_printf_parse("parse_stream return 1: done_word!=0\n");
return 1;
}
if (ch == EOF)
break;
/* If we aren't performing a substitution, treat
* a newline as a command separator.
* [why we don't handle it exactly like ';'? --vda] */
if (end_trigger && ch == '\n') {
done_pipe(ctx, PIPE_SEQ);
}
}
if (end_trigger) {
if (!shadow_quote && strchr(end_trigger, ch)) {
/* Special case: (...word) makes last word terminate,
* as if ';' is seen */
if (ch == ')') {
done_word(dest, ctx);
//err chk?
done_pipe(ctx, PIPE_SEQ);
}
if (!HAS_KEYWORDS IF_HAS_KEYWORDS(|| ctx->ctx_res_w == RES_NONE)) {
debug_printf_parse("parse_stream return 0: end_trigger char found\n");
return 0;
}
}
}
if (m == CHAR_IFS)
continue;
if (dest->o_assignment == MAYBE_ASSIGNMENT) {
/* ch is a special char and thus this word
* cannot be an assignment: */
dest->o_assignment = NOT_ASSIGNMENT;
}
switch (ch) {
case '#':
if (dest->length == 0 && !shadow_quote) {
while (1) {
ch = i_peek(input);
if (ch == EOF || ch == '\n')
break;
i_getch(input);
}
} else {
o_addQchr(dest, ch);
}
break;
case '\\':
if (next == EOF) {
syntax("\\<eof>");
debug_printf_parse("parse_stream return 1: \\<eof>\n");
return 1;
}
/* bash:
* "The backslash retains its special meaning [in "..."]
* only when followed by one of the following characters:
* $, `, ", \, or <newline>. A double quote may be quoted
* within double quotes by preceding it with a backslash.
* If enabled, history expansion will be performed unless
* an ! appearing in double quotes is escaped using
* a backslash. The backslash preceding the ! is not removed."
*/
if (shadow_quote) { //NOT SURE dest->o_quote) {
if (strchr("$`\"\\", next) != NULL) {
o_addqchr(dest, i_getch(input));
} else {
o_addqchr(dest, '\\');
}
} else {
o_addchr(dest, '\\');
o_addchr(dest, i_getch(input));
}
break;
case '$':
if (handle_dollar(dest, input) != 0) {
debug_printf_parse("parse_stream return 1: handle_dollar returned non-0\n");
return 1;
}
break;
case '\'':
dest->nonnull = 1;
while (1) {
ch = i_getch(input);
if (ch == EOF) {
syntax("unterminated '");
debug_printf_parse("parse_stream return 1: unterminated '\n");
return 1;
}
if (ch == '\'')
break;
if (dest->o_assignment == NOT_ASSIGNMENT)
o_addqchr(dest, ch);
else
o_addchr(dest, ch);
}
break;
case '"':
dest->nonnull = 1;
shadow_quote ^= 1; /* invert */
if (dest->o_assignment == NOT_ASSIGNMENT)
dest->o_quote ^= 1;
break;
#if ENABLE_HUSH_TICK
case '`': {
//int pos = dest->length;
o_addchr(dest, SPECIAL_VAR_SYMBOL);
o_addchr(dest, shadow_quote /*or dest->o_quote??*/ ? 0x80 | '`' : '`');
add_till_backquote(dest, input);
o_addchr(dest, SPECIAL_VAR_SYMBOL);
//debug_printf_subst("SUBST RES3 '%s'\n", dest->data + pos);
break;
}
#endif
case '>':
redir_fd = redirect_opt_num(dest);
done_word(dest, ctx);
redir_style = REDIRECT_OVERWRITE;
if (next == '>') {
redir_style = REDIRECT_APPEND;
i_getch(input);
}
#if 0
else if (next == '(') {
syntax(">(process) not supported");
debug_printf_parse("parse_stream return 1: >(process) not supported\n");
return 1;
}
#endif
setup_redirect(ctx, redir_fd, redir_style, input);
break;
case '<':
redir_fd = redirect_opt_num(dest);
done_word(dest, ctx);
redir_style = REDIRECT_INPUT;
if (next == '<') {
redir_style = REDIRECT_HEREIS;
i_getch(input);
} else if (next == '>') {
redir_style = REDIRECT_IO;
i_getch(input);
}
#if 0
else if (next == '(') {
syntax("<(process) not supported");
debug_printf_parse("parse_stream return 1: <(process) not supported\n");
return 1;
}
#endif
setup_redirect(ctx, redir_fd, redir_style, input);
break;
case ';':
done_word(dest, ctx);
done_pipe(ctx, PIPE_SEQ);
break;
case '&':
done_word(dest, ctx);
if (next == '&') {
i_getch(input);
done_pipe(ctx, PIPE_AND);
} else {
done_pipe(ctx, PIPE_BG);
}
break;
case '|':
done_word(dest, ctx);
if (next == '|') {
i_getch(input);
done_pipe(ctx, PIPE_OR);
} else {
/* we could pick up a file descriptor choice here
* with redirect_opt_num(), but bash doesn't do it.
* "echo foo 2| cat" yields "foo 2". */
done_command(ctx);
}
break;
case '(':
case '{':
if (parse_group(dest, ctx, input, ch) != 0) {
debug_printf_parse("parse_stream return 1: parse_group returned non-0\n");
return 1;
}
break;
case ')':
case '}':
/* proper use of this character is caught by end_trigger */
syntax("unexpected } or )");
debug_printf_parse("parse_stream return 1: unexpected '}'\n");
return 1;
default:
if (HUSH_DEBUG)
bb_error_msg_and_die("BUG: unexpected %c\n", ch);
}
} /* while (1) */
debug_printf_parse("parse_stream return %d\n", -(end_trigger != NULL));
if (end_trigger)
return -1;
return 0;
}
static void set_in_charmap(const char *set, int code)
{
while (*set)
charmap[(unsigned char)*set++] = code;
}
static void update_charmap(void)
{
/* char *ifs and char charmap[256] are both globals. */
ifs = getenv("IFS");
if (ifs == NULL)
ifs = " \t\n";
/* Precompute a list of 'flow through' behavior so it can be treated
* quickly up front. Computation is necessary because of IFS.
* Special case handling of IFS == " \t\n" is not implemented.
* The charmap[] array only really needs two bits each,
* and on most machines that would be faster (reduced L1 cache use).
*/
memset(charmap, CHAR_ORDINARY, sizeof(charmap));
#if ENABLE_HUSH_TICK
set_in_charmap("\\$\"`", CHAR_SPECIAL);
#else
set_in_charmap("\\$\"", CHAR_SPECIAL);
#endif
set_in_charmap("<>;&|(){}#'", CHAR_ORDINARY_IF_QUOTED);
set_in_charmap(ifs, CHAR_IFS); /* are ordinary if quoted */
}
/* Most recursion does not come through here, the exception is
* from builtin_source() and builtin_eval() */
static int parse_and_run_stream(struct in_str *inp, int parse_flag)
{
struct p_context ctx;
o_string temp = NULL_O_STRING;
int rcode;
do {
initialize_context(&ctx);
update_charmap();
#if ENABLE_HUSH_INTERACTIVE
inp->promptmode = 0; /* PS1 */
#endif
/* We will stop & execute after each ';' or '\n'.
* Example: "sleep 9999; echo TEST" + ctrl-C:
* TEST should be printed */
rcode = parse_stream(&temp, &ctx, inp, ";\n");
#if HAS_KEYWORDS
if (rcode != 1 && ctx.old_flag != 0) {
syntax(NULL);
}
#endif
if (rcode != 1 IF_HAS_KEYWORDS(&& ctx.old_flag == 0)) {
done_word(&temp, &ctx);
done_pipe(&ctx, PIPE_SEQ);
debug_print_tree(ctx.list_head, 0);
debug_printf_exec("parse_stream_outer: run_and_free_list\n");
run_and_free_list(ctx.list_head);
} else {
/* We arrive here also if rcode == 1 (error in parse_stream) */
#if HAS_KEYWORDS
if (ctx.old_flag != 0) {
free(ctx.stack);
o_reset(&temp);
}
#endif
/*temp.nonnull = 0; - o_free does it below */
/*temp.o_quote = 0; - o_free does it below */
free_pipe_list(ctx.list_head, /* indent: */ 0);
/* Discard all unprocessed line input, force prompt on */
inp->p = NULL;
#if ENABLE_HUSH_INTERACTIVE
inp->promptme = 1;
#endif
}
o_free(&temp);
/* loop on syntax errors, return on EOF: */
} while (rcode != -1 && !(parse_flag & PARSEFLAG_EXIT_FROM_LOOP));
return 0;
}
static int parse_and_run_string(const char *s, int parse_flag)
{
struct in_str input;
setup_string_in_str(&input, s);
return parse_and_run_stream(&input, parse_flag);
}
static int parse_and_run_file(FILE *f)
{
int rcode;
struct in_str input;
setup_file_in_str(&input, f);
rcode = parse_and_run_stream(&input, 0 /* parse_flag */);
return rcode;
}
#if ENABLE_HUSH_JOB
/* Make sure we have a controlling tty. If we get started under a job
* aware app (like bash for example), make sure we are now in charge so
* we don't fight over who gets the foreground */
static void setup_job_control(void)
{
pid_t shell_pgrp;
saved_task_pgrp = shell_pgrp = getpgrp();
debug_printf_jobs("saved_task_pgrp=%d\n", saved_task_pgrp);
close_on_exec_on(interactive_fd);
/* If we were ran as 'hush &',
* sleep until we are in the foreground. */
while (tcgetpgrp(interactive_fd) != shell_pgrp) {
/* Send TTIN to ourself (should stop us) */
kill(- shell_pgrp, SIGTTIN);
shell_pgrp = getpgrp();
}
/* Ignore job-control and misc signals. */
set_jobctrl_sighandler(SIG_IGN);
set_misc_sighandler(SIG_IGN);
//huh? signal(SIGCHLD, SIG_IGN);
/* We _must_ restore tty pgrp on fatal signals */
set_fatal_sighandler(sigexit);
/* Put ourselves in our own process group. */
setpgrp(); /* is the same as setpgid(our_pid, our_pid); */
/* Grab control of the terminal. */
tcsetpgrp(interactive_fd, getpid());
}
#endif
int hush_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
int hush_main(int argc, char **argv)
{
static const char version_str[] ALIGN1 = "HUSH_VERSION="HUSH_VER_STR;
static const struct variable const_shell_ver = {
.next = NULL,
.varstr = (char*)version_str,
.max_len = 1, /* 0 can provoke free(name) */
.flg_export = 1,
.flg_read_only = 1,
};
int opt;
FILE *input;
char **e;
struct variable *cur_var;
INIT_G();
root_pid = getpid();
/* Deal with HUSH_VERSION */
shell_ver = const_shell_ver; /* copying struct here */
top_var = &shell_ver;
unsetenv("HUSH_VERSION"); /* in case it exists in initial env */
/* Initialize our shell local variables with the values
* currently living in the environment */
cur_var = top_var;
e = environ;
if (e) while (*e) {
char *value = strchr(*e, '=');
if (value) { /* paranoia */
cur_var->next = xzalloc(sizeof(*cur_var));
cur_var = cur_var->next;
cur_var->varstr = *e;
cur_var->max_len = strlen(*e);
cur_var->flg_export = 1;
}
e++;
}
putenv((char *)version_str); /* reinstate HUSH_VERSION */
#if ENABLE_FEATURE_EDITING
line_input_state = new_line_input_t(FOR_SHELL);
#endif
/* XXX what should these be while sourcing /etc/profile? */
global_argc = argc;
global_argv = argv;
/* Initialize some more globals to non-zero values */
set_cwd();
#if ENABLE_HUSH_INTERACTIVE
#if ENABLE_FEATURE_EDITING
cmdedit_set_initial_prompt();
#endif
PS2 = "> ";
#endif
if (EXIT_SUCCESS) /* otherwise is already done */
last_return_code = EXIT_SUCCESS;
if (argv[0] && argv[0][0] == '-') {
debug_printf("sourcing /etc/profile\n");
input = fopen("/etc/profile", "r");
if (input != NULL) {
close_on_exec_on(fileno(input));
parse_and_run_file(input);
fclose(input);
}
}
input = stdin;
while ((opt = getopt(argc, argv, "c:xif")) > 0) {
switch (opt) {
case 'c':
global_argv = argv + optind;
global_argc = argc - optind;
opt = parse_and_run_string(optarg, 0 /* parse_flag */);
goto final_return;
case 'i':
/* Well, we cannot just declare interactiveness,
* we have to have some stuff (ctty, etc) */
/* interactive_fd++; */
break;
case 'f':
fake_mode = 1;
break;
default:
#ifndef BB_VER
fprintf(stderr, "Usage: sh [FILE]...\n"
" or: sh -c command [args]...\n\n");
exit(EXIT_FAILURE);
#else
bb_show_usage();
#endif
}
}
#if ENABLE_HUSH_JOB
/* A shell is interactive if the '-i' flag was given, or if all of
* the following conditions are met:
* no -c command
* no arguments remaining or the -s flag given
* standard input is a terminal
* standard output is a terminal
* Refer to Posix.2, the description of the 'sh' utility. */
if (argv[optind] == NULL && input == stdin
&& isatty(STDIN_FILENO) && isatty(STDOUT_FILENO)
) {
saved_tty_pgrp = tcgetpgrp(STDIN_FILENO);
debug_printf("saved_tty_pgrp=%d\n", saved_tty_pgrp);
if (saved_tty_pgrp >= 0) {
/* try to dup to high fd#, >= 255 */
interactive_fd = fcntl(STDIN_FILENO, F_DUPFD, 255);
if (interactive_fd < 0) {
/* try to dup to any fd */
interactive_fd = dup(STDIN_FILENO);
if (interactive_fd < 0)
/* give up */
interactive_fd = 0;
}
// TODO: track & disallow any attempts of user
// to (inadvertently) close/redirect it
}
}
debug_printf("interactive_fd=%d\n", interactive_fd);
if (interactive_fd) {
fcntl(interactive_fd, F_SETFD, FD_CLOEXEC);
/* Looks like they want an interactive shell */
setup_job_control();
/* -1 is special - makes xfuncs longjmp, not exit
* (we reset die_sleep = 0 whereever we [v]fork) */
die_sleep = -1;
if (setjmp(die_jmp)) {
/* xfunc has failed! die die die */
hush_exit(xfunc_error_retval);
}
#if !ENABLE_FEATURE_SH_EXTRA_QUIET
printf("\n\n%s hush - the humble shell v"HUSH_VER_STR"\n", bb_banner);
printf("Enter 'help' for a list of built-in commands.\n\n");
#endif
}
#elif ENABLE_HUSH_INTERACTIVE
/* no job control compiled, only prompt/line editing */
if (argv[optind] == NULL && input == stdin
&& isatty(STDIN_FILENO) && isatty(STDOUT_FILENO)
) {
interactive_fd = fcntl(STDIN_FILENO, F_DUPFD, 255);
if (interactive_fd < 0) {
/* try to dup to any fd */
interactive_fd = dup(STDIN_FILENO);
if (interactive_fd < 0)
/* give up */
interactive_fd = 0;
}
if (interactive_fd) {
fcntl(interactive_fd, F_SETFD, FD_CLOEXEC);
set_misc_sighandler(SIG_IGN);
}
}
#endif
if (argv[optind] == NULL) {
opt = parse_and_run_file(stdin);
} else {
debug_printf("\nrunning script '%s'\n", argv[optind]);
global_argv = argv + optind;
global_argc = argc - optind;
input = xfopen(argv[optind], "r");
fcntl(fileno(input), F_SETFD, FD_CLOEXEC);
opt = parse_and_run_file(input);
}
final_return:
#if ENABLE_FEATURE_CLEAN_UP
fclose(input);
if (cwd != bb_msg_unknown)
free((char*)cwd);
cur_var = top_var->next;
while (cur_var) {
struct variable *tmp = cur_var;
if (!cur_var->max_len)
free(cur_var->varstr);
cur_var = cur_var->next;
free(tmp);
}
#endif
hush_exit(opt ? opt : last_return_code);
}
#if ENABLE_LASH
int lash_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
int lash_main(int argc, char **argv)
{
//bb_error_msg("lash is deprecated, please use hush instead");
return hush_main(argc, argv);
}
#endif
/*
* Built-ins
*/
static int builtin_true(char **argv ATTRIBUTE_UNUSED)
{
return 0;
}
static int builtin_test(char **argv)
{
int argc = 0;
while (*argv) {
argc++;
argv++;
}
return test_main(argc, argv - argc);
}
static int builtin_echo(char **argv)
{
int argc = 0;
while (*argv) {
argc++;
argv++;
}
return echo_main(argc, argv - argc);
}
static int builtin_eval(char **argv)
{
int rcode = EXIT_SUCCESS;
if (argv[1]) {
char *str = expand_strvec_to_string(argv + 1);
parse_and_run_string(str, PARSEFLAG_EXIT_FROM_LOOP);
free(str);
rcode = last_return_code;
}
return rcode;
}
static int builtin_cd(char **argv)
{
const char *newdir;
if (argv[1] == NULL) {
// bash does nothing (exitcode 0) if HOME is ""; if it's unset,
// bash says "bash: cd: HOME not set" and does nothing (exitcode 1)
newdir = getenv("HOME") ? : "/";
} else
newdir = argv[1];
if (chdir(newdir)) {
printf("cd: %s: %s\n", newdir, strerror(errno));
return EXIT_FAILURE;
}
set_cwd();
return EXIT_SUCCESS;
}
static int builtin_exec(char **argv)
{
if (argv[1] == NULL)
return EXIT_SUCCESS; /* bash does this */
{
#if !BB_MMU
char **ptrs2free = alloc_ptrs(argv);
#endif
// FIXME: if exec fails, bash does NOT exit! We do...
pseudo_exec_argv(ptrs2free, argv + 1);
/* never returns */
}
}
static int builtin_exit(char **argv)
{
// TODO: bash does it ONLY on top-level sh exit (+interacive only?)
//puts("exit"); /* bash does it */
// TODO: warn if we have background jobs: "There are stopped jobs"
// On second consecutive 'exit', exit anyway.
if (argv[1] == NULL)
hush_exit(last_return_code);
/* mimic bash: exit 123abc == exit 255 + error msg */
xfunc_error_retval = 255;
/* bash: exit -2 == exit 254, no error msg */
hush_exit(xatoi(argv[1]) & 0xff);
}
static int builtin_export(char **argv)
{
const char *value;
char *name = argv[1];
if (name == NULL) {
// TODO:
// ash emits: export VAR='VAL'
// bash: declare -x VAR="VAL"
// (both also escape as needed (quotes, $, etc))
char **e = environ;
if (e)
while (*e)
puts(*e++);
return EXIT_SUCCESS;
}
value = strchr(name, '=');
if (!value) {
/* They are exporting something without a =VALUE */
struct variable *var;
var = get_local_var(name);
if (var) {
var->flg_export = 1;
putenv(var->varstr);
}
/* bash does not return an error when trying to export
* an undefined variable. Do likewise. */
return EXIT_SUCCESS;
}
set_local_var(xstrdup(name), 1);
return EXIT_SUCCESS;
}
#if ENABLE_HUSH_JOB
/* built-in 'fg' and 'bg' handler */
static int builtin_fg_bg(char **argv)
{
int i, jobnum;
struct pipe *pi;
if (!interactive_fd)
return EXIT_FAILURE;
/* If they gave us no args, assume they want the last backgrounded task */
if (!argv[1]) {
for (pi = job_list; pi; pi = pi->next) {
if (pi->jobid == last_jobid) {
goto found;
}
}
bb_error_msg("%s: no current job", argv[0]);
return EXIT_FAILURE;
}
if (sscanf(argv[1], "%%%d", &jobnum) != 1) {
bb_error_msg("%s: bad argument '%s'", argv[0], argv[1]);
return EXIT_FAILURE;
}
for (pi = job_list; pi; pi = pi->next) {
if (pi->jobid == jobnum) {
goto found;
}
}
bb_error_msg("%s: %d: no such job", argv[0], jobnum);
return EXIT_FAILURE;
found:
// TODO: bash prints a string representation
// of job being foregrounded (like "sleep 1 | cat")
if (*argv[0] == 'f') {
/* Put the job into the foreground. */
tcsetpgrp(interactive_fd, pi->pgrp);
}
/* Restart the processes in the job */
debug_printf_jobs("reviving %d procs, pgrp %d\n", pi->num_progs, pi->pgrp);
for (i = 0; i < pi->num_progs; i++) {
debug_printf_jobs("reviving pid %d\n", pi->progs[i].pid);
pi->progs[i].is_stopped = 0;
}
pi->stopped_progs = 0;
i = kill(- pi->pgrp, SIGCONT);
if (i < 0) {
if (errno == ESRCH) {
delete_finished_bg_job(pi);
return EXIT_SUCCESS;
} else {
bb_perror_msg("kill (SIGCONT)");
}
}
if (*argv[0] == 'f') {
remove_bg_job(pi);
return checkjobs_and_fg_shell(pi);
}
return EXIT_SUCCESS;
}
#endif
#if ENABLE_HUSH_HELP
static int builtin_help(char **argv ATTRIBUTE_UNUSED)
{
const struct built_in_command *x;
printf("\nBuilt-in commands:\n");
printf("-------------------\n");
for (x = bltins; x != &bltins[ARRAY_SIZE(bltins)]; x++) {
printf("%s\t%s\n", x->cmd, x->descr);
}
printf("\n\n");
return EXIT_SUCCESS;
}
#endif
#if ENABLE_HUSH_JOB
static int builtin_jobs(char **argv ATTRIBUTE_UNUSED)
{
struct pipe *job;
const char *status_string;
for (job = job_list; job; job = job->next) {
if (job->alive_progs == job->stopped_progs)
status_string = "Stopped";
else
status_string = "Running";
printf(JOB_STATUS_FORMAT, job->jobid, status_string, job->cmdtext);
}
return EXIT_SUCCESS;
}
#endif
static int builtin_pwd(char **argv ATTRIBUTE_UNUSED)
{
puts(set_cwd());
return EXIT_SUCCESS;
}
static int builtin_read(char **argv)
{
char *string;
const char *name = argv[1] ? argv[1] : "REPLY";
string = xmalloc_reads(STDIN_FILENO, xasprintf("%s=", name), NULL);
return set_local_var(string, 0);
}
/* built-in 'set [VAR=value]' handler */
static int builtin_set(char **argv)
{
char *temp = argv[1];
struct variable *e;
if (temp == NULL)
for (e = top_var; e; e = e->next)
puts(e->varstr);
else
set_local_var(xstrdup(temp), 0);
return EXIT_SUCCESS;
}
static int builtin_shift(char **argv)
{
int n = 1;
if (argv[1]) {
n = atoi(argv[1]);
}
if (n >= 0 && n < global_argc) {
global_argv[n] = global_argv[0];
global_argc -= n;
global_argv += n;
return EXIT_SUCCESS;
}
return EXIT_FAILURE;
}
static int builtin_source(char **argv)
{
FILE *input;
int status;
if (argv[1] == NULL)
return EXIT_FAILURE;
/* XXX search through $PATH is missing */
input = fopen(argv[1], "r");
if (!input) {
bb_error_msg("cannot open '%s'", argv[1]);
return EXIT_FAILURE;
}
close_on_exec_on(fileno(input));
/* Now run the file */
/* XXX argv and argc are broken; need to save old global_argv
* (pointer only is OK!) on this stack frame,
* set global_argv=argv+1, recurse, and restore. */
status = parse_and_run_file(input);
fclose(input);
return status;
}
static int builtin_umask(char **argv)
{
mode_t new_umask;
const char *arg = argv[1];
char *end;
if (arg) {
new_umask = strtoul(arg, &end, 8);
if (*end != '\0' || end == arg) {
return EXIT_FAILURE;
}
} else {
new_umask = umask(0);
printf("%.3o\n", (unsigned) new_umask);
}
umask(new_umask);
return EXIT_SUCCESS;
}
static int builtin_unset(char **argv)
{
/* bash always returns true */
unset_local_var(argv[1]);
return EXIT_SUCCESS;
}