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coral / busybox / refs/tags/1_9_0 / . / shell / hush.c
blob: cb2c3e98e793fcd17c1d48c2582de58e81141c13 [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:
* b_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?)
* $_
* ! negation operator for pipes
* &> 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?
* finish implementing reserved words: for, while, until, do, done
* change { and } from special chars to reserved words
* builtins: break, continue, eval, return, set, trap, ulimit
* test magic exec
* handle children going into background
* clean up recognition of null pipes
* check setting of global_argc and global_argv
* control-C handling, probably with longjmp
* follow IFS rules more precisely, including update semantics
* figure out what to do with backslash-newline
* explain why we use signal instead of sigaction
* propagate syntax errors, die on resource errors?
* continuation lines, both explicit and implicit - done?
* memory leak finding and plugging - done?
* more testing, especially quoting rules and redirection
* document how quoting rules not precisely followed for variable assignments
* maybe change charmap[] to use 2-bit entries
* (eventually) remove all the printf's
*
* Licensed under the GPL v2 or later, see the file LICENSE in this tarball.
*/
#include <glob.h> /* glob, of course */
#include <getopt.h> /* should be pretty obvious */
/* #include <dmalloc.h> */
extern char **environ; /* This is in <unistd.h>, but protected with __USE_GNU */
#include "busybox.h" /* for APPLET_IS_NOFORK/NOEXEC */
#if !BB_MMU
/* A bit drastic. Can allow some simpler commands
* by analysing command in generate_stream_from_list()
*/
#undef ENABLE_HUSH_TICK
#define ENABLE_HUSH_TICK 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_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_SHELL_JOBS 1
#endif
#ifndef debug_printf_expand
#define debug_printf_expand(...) fprintf(stderr, __VA_ARGS__)
#define DEBUG_EXPAND 1
#endif
/* Keep unconditionally on for now */
#define ENABLE_HUSH_DEBUG 1
#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
/*
* Leak hunting. Use hush_leaktool.sh for post-processing.
*/
#ifdef FOR_HUSH_LEAKTOOL
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
#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
#define SPECIAL_VAR_SYMBOL 3
#define PARSEFLAG_EXIT_FROM_LOOP 1
#define PARSEFLAG_SEMICOLON (1 << 1) /* symbol ';' is special for parser */
#define PARSEFLAG_REPARSING (1 << 2) /* >= 2nd pass */
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;
/* might eventually control execution */
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;
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 ),
};
/* 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;
smallint res_w;
smallint parse_type; /* bitmask of PARSEFLAG_xxx, defines type of parser : ";$" common or special symbol */
int old_flag; /* bitmask of FLAG_xxx, for figuring out valid reserved words */
struct p_context *stack;
/* How about quoting status? */
};
struct redir_struct {
struct redir_struct *next; /* pointer to the next redirect in the list */
redir_type type; /* type of redirection */
int fd; /* file descriptor being redirected */
int dup; /* -1, or file descriptor being duplicated */
char **glob_word; /* *word.gl_pathv is the filename */
};
struct child_prog {
pid_t pid; /* 0 if exited */
char **argv; /* program name and arguments */
struct pipe *group; /* if non-NULL, first in group or subshell */
smallint subshell; /* flag, non-zero if group must be forked */
smallint is_stopped; /* is the program currently running? */
struct redir_struct *redirects; /* I/O redirections */
struct pipe *family; /* pointer back to the child's parent pipe */
//sp counting seems to be broken... so commented out, grep for '//sp:'
//sp: int sp; /* number of SPECIAL_VAR_SYMBOL */
//seems to be unused, grep for '//pt:'
//pt: int parse_type;
};
/* 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 .$*.
*/
struct pipe {
struct pipe *next;
int num_progs; /* total number of programs in job */
int running_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
char *cmdbuf; /* buffer various argv's point into */
struct child_prog *progs; /* array of commands in pipe */
int job_context; /* bitmask defining current context */
smallint followup; /* PIPE_BG, PIPE_SEQ, PIPE_OR, PIPE_AND */
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;
smallint o_quote;
smallint nonnull;
} o_string;
#define NULL_O_STRING {NULL,0,0,0,0}
/* used for initialization: o_string foo = NULL_O_STRING; */
/* 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 b_getch(input) ((input)->get(input))
#define b_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
#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
#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 B_CHUNK 100
#define B_NOSPAC 1
#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: */
/* o_string manipulation: */
static int b_check_space(o_string *o, int len);
static int b_addchr(o_string *o, int ch);
static void b_reset(o_string *o);
static int b_addqchr(o_string *o, int ch, int quote);
/* 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_real(struct pipe *pi);
static void pseudo_exec_argv(char **argv) ATTRIBUTE_NORETURN;
static void pseudo_exec(struct child_prog *child) ATTRIBUTE_NORETURN;
static int run_pipe_real(struct pipe *pi);
/* extended glob support: */
static char **globhack(const char *src, char **strings);
static int glob_needed(const char *s);
static int xglob(o_string *dest, char ***pglob);
/* variable assignment: */
static int is_assignment(const char *s);
/* 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 int 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 p_context *ctx, 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 p_context *ctx, 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 char **add_strings_to_strings(int need_xstrdup, 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] = need_xstrdup ? xstrdup(add[i]) : add[i];
return v;
}
/* 'add' should be a malloced pointer */
static char **add_string_to_strings(char **strings, char *add)
{
char *v[2];
v[0] = add;
v[1] = NULL;
return add_strings_to_strings(0, strings, v);
}
static void free_strings(char **strings)
{
if (strings) {
char **v = strings;
while (*v)
free(*v++);
free(strings);
}
}
/* 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_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; /* name */
int (*function) (char **argv); /* function ptr */
#if ENABLE_HUSH_HELP
const char *descr; /* description */
#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_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 working 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, "Exec command, replacing this shell with the exec'd process"),
BLTIN("exit" , builtin_exit, "Exit from shell"),
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, "Lists the active jobs"),
#endif
// TODO: remove pwd? we have it as an applet...
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, "Controls resource limits"),
BLTIN("umask" , builtin_umask, "Sets file creation mask"),
BLTIN("unset" , builtin_unset, "Unset environment variable"),
BLTIN("." , builtin_source, "Source-in and run commands in a file"),
#if ENABLE_HUSH_HELP
BLTIN("help" , builtin_help, "List shell built-in commands"),
#endif
BLTIN(NULL, NULL, NULL)
};
#if ENABLE_HUSH_JOB
/* move to libbb? */
static void signal_SA_RESTART(int sig, void (*handler)(int))
{
struct sigaction sa;
sa.sa_handler = handler;
sa.sa_flags = SA_RESTART;
sigemptyset(&sa.sa_mask);
sigaction(sig, &sa, NULL);
}
/* Signals are grouped, we handle them in batches */
static void set_fatal_sighandler(void (*handler)(int))
{
signal(SIGILL , handler);
signal(SIGTRAP, handler);
signal(SIGABRT, handler);
signal(SIGFPE , handler);
signal(SIGBUS , handler);
signal(SIGSEGV, handler);
/* bash 3.2 seems to handle these just like 'fatal' ones */
signal(SIGHUP , handler);
signal(SIGPIPE, handler);
signal(SIGALRM, handler);
}
static void set_jobctrl_sighandler(void (*handler)(int))
{
signal(SIGTSTP, handler);
signal(SIGTTIN, handler);
signal(SIGTTOU, handler);
}
static void set_misc_sighandler(void (*handler)(int))
{
signal(SIGINT , handler);
signal(SIGQUIT, handler);
signal(SIGTERM, 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)
{
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)
{
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 */
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)
{
sigset_t block_all;
/* Disable all signals: job control, SIGPIPE, etc. */
sigfillset(&block_all);
sigprocmask(SIG_SETMASK, &block_all, NULL);
if (interactive_fd)
tcsetpgrp(interactive_fd, saved_tty_pgrp);
/* Not a signal, just exit */
if (sig <= 0)
_exit(- sig);
/* Enable only this sig and kill ourself with it */
signal(sig, SIG_DFL);
sigdelset(&block_all, sig);
sigprocmask(SIG_SETMASK, &block_all, NULL);
raise(sig);
_exit(1); /* Should not reach it */
}
/* 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 set_misc_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;
}
/* built-in 'test' handler */
static int builtin_test(char **argv)
{
int argc = 0;
while (*argv) {
argc++;
argv++;
}
return test_main(argc, argv - argc);
}
/* built-in 'test' handler */
static int builtin_echo(char **argv)
{
int argc = 0;
while (*argv) {
argc++;
argv++;
}
return echo_main(argc, argv - argc);
}
/* built-in 'eval' handler */
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 |
PARSEFLAG_SEMICOLON);
free(str);
rcode = last_return_code;
}
return rcode;
}
/* built-in 'cd <path>' handler */
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;
}
/* built-in 'exec' handler */
static int builtin_exec(char **argv)
{
if (argv[1] == NULL)
return EXIT_SUCCESS; /* Really? */
pseudo_exec_argv(argv + 1);
/* never returns */
}
/* built-in 'exit' handler */
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);
}
/* built-in 'export VAR=value' handler */
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
/* built-in 'help' handler */
#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->cmd; x++) {
printf("%s\t%s\n", x->cmd, x->descr);
}
printf("\n\n");
return EXIT_SUCCESS;
}
#endif
#if ENABLE_HUSH_JOB
/* built-in 'jobs' handler */
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->running_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
/* built-in 'pwd' handler */
static int builtin_pwd(char **argv ATTRIBUTE_UNUSED)
{
puts(set_cwd());
return EXIT_SUCCESS;
}
/* built-in 'read VAR' handler */
static int builtin_read(char **argv)
{
char *string;
const char *name = argv[1] ? argv[1] : "REPLY";
string = xmalloc_reads(STDIN_FILENO, xasprintf("%s=", name));
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;
}
/* Built-in 'shift' handler */
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;
}
/* Built-in '.' handler (read-in and execute commands from file) */
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;
}
/* built-in 'unset VAR' handler */
static int builtin_unset(char **argv)
{
/* bash always returns true */
unset_local_var(argv[1]);
return EXIT_SUCCESS;
}
//static int builtin_not_written(char **argv)
//{
// printf("builtin_%s not written\n", argv[0]);
// return EXIT_FAILURE;
//}
static int b_check_space(o_string *o, int len)
{
/* It would be easy to drop a more restrictive policy
* in here, such as setting a maximum string length */
if (o->length + len > o->maxlen) {
/* assert(data == NULL || o->maxlen != 0); */
o->maxlen += (2*len > B_CHUNK ? 2*len : B_CHUNK);
o->data = xrealloc(o->data, 1 + o->maxlen);
}
return o->data == NULL;
}
static int b_addchr(o_string *o, int ch)
{
debug_printf("b_addchr: '%c' o->length=%d o=%p\n", ch, o->length, o);
if (b_check_space(o, 1))
return B_NOSPAC;
o->data[o->length] = ch;
o->length++;
o->data[o->length] = '\0';
return 0;
}
static void b_reset(o_string *o)
{
o->length = 0;
o->nonnull = 0;
if (o->data)
o->data[0] = '\0';
}
static void b_free(o_string *o)
{
free(o->data);
memset(o, 0, sizeof(*o));
}
/* My analysis of quoting semantics tells me that state information
* is associated with a destination, not a source.
*/
static int b_addqchr(o_string *o, int ch, int quote)
{
if (quote && strchr("*?[\\", ch)) {
int rc;
rc = b_addchr(o, '\\');
if (rc)
return rc;
}
return b_addchr(o, ch);
}
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; otherwise, we'll end up bequeathing
* atexit() handlers and other unwanted stuff to our
* child processes (rob@sysgo.de) */
r = read_line_input(prompt_str, user_input_buf, BUFSIZ-1, line_input_state);
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->glob_word == NULL) {
/* something went wrong in the parse. Pretend it didn't happen */
continue;
}
if (redir->dup == -1) {
char *p;
mode = redir_table[redir->type].mode;
p = expand_string_to_string(redir->glob_word[0]);
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_real(), 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 **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]);
// FIXME: vfork case??
p = expand_string_to_string(argv[i]);
putenv(p);
}
argv += i;
/* If a variable is assigned in a forest, and nobody listens,
* was it ever really set?
*/
if (argv[0] == NULL) {
_exit(EXIT_SUCCESS);
}
argv = expand_strvec_to_strvec(argv);
/*
* 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->cmd; 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(1);
}
/* Called after [v]fork() in run_pipe_real()
*/
static void pseudo_exec(struct child_prog *child)
{
// FIXME: buggy wrt NOMMU! Must not modify any global data
// until it does exec/_exit, but currently it does.
if (child->argv) {
pseudo_exec_argv(child->argv);
}
if (child->group) {
#if !BB_MMU
bb_error_msg_and_die("nested lists are not supported on NOMMU");
#else
int rcode;
#if ENABLE_HUSH_INTERACTIVE
debug_printf_exec("pseudo_exec: setting interactive_fd=0\n");
interactive_fd = 0; /* crucial!!!! */
#endif
debug_printf_exec("pseudo_exec: run_list_real\n");
rcode = run_list_real(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])
return (pi->cmdtext = xzalloc(1));
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 */
/* Checks 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
int prognum = 0;
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:
while ((childpid = waitpid(-1, &status, attributes)) > 0) {
const int dead = WIFEXITED(status) || WIFSIGNALED(status);
#ifdef DEBUG_SHELL_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) {
int i;
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) {
/* printf("process %d exit %d\n", i, WEXITSTATUS(status)); */
if (dead) {
fg_pipe->progs[i].pid = 0;
fg_pipe->running_progs--;
if (i == fg_pipe->num_progs-1)
/* last process gives overall exitstatus */
rcode = WEXITSTATUS(status);
} else {
fg_pipe->progs[i].is_stopped = 1;
fg_pipe->stopped_progs++;
}
debug_printf_jobs("fg_pipe: running_progs %d stopped_progs %d\n",
fg_pipe->running_progs, fg_pipe->stopped_progs);
if (fg_pipe->running_progs - fg_pipe->stopped_progs <= 0) {
/* All processes in fg pipe have exited/stopped */
#if ENABLE_HUSH_JOB
if (fg_pipe->running_progs)
insert_bg_job(fg_pipe);
#endif
return rcode;
}
/* There are still running processes in the fg pipe */
goto wait_more;
}
}
/* fall through to searching 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) {
prognum = 0;
while (prognum < pi->num_progs) {
if (pi->progs[prognum].pid == childpid)
goto found_pi_and_prognum;
prognum++;
}
}
#endif
/* Happens when shell is used as init process (init=/bin/sh) */
debug_printf("checkjobs: pid %d was not in our list!\n", childpid);
goto wait_more;
#if ENABLE_HUSH_JOB
found_pi_and_prognum:
if (dead) {
/* child exited */
pi->progs[prognum].pid = 0;
pi->running_progs--;
if (!pi->running_progs) {
printf(JOB_STATUS_FORMAT, pi->jobid,
"Done", pi->cmdtext);
delete_finished_bg_job(pi);
}
} else {
/* child stopped */
pi->stopped_progs++;
pi->progs[prognum].is_stopped = 1;
}
#endif
}
/* 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);
if (tcsetpgrp(interactive_fd, p) && errno != ENOTTY)
bb_perror_msg("tcsetpgrp-4a");
return rcode;
}
#endif
/* run_pipe_real() 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_real 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_real(struct pipe *pi)
{
int i;
int nextin, nextout;
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_real start: single_fg=%d\n", single_fg);
nextin = 0;
#if ENABLE_HUSH_JOB
pi->pgrp = -1;
#endif
pi->running_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_real\n");
rcode = run_list_real(child->group);
restore_redirects(squirrel);
debug_printf_exec("run_pipe_real return %d\n", rcode);
return rcode; // do we need to add '... & 0xff' ?
}
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]);
//sp: child->sp--;
putenv(p);
}
for (x = bltins; x->cmd; 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]);
//sp: if (child->sp) /* btw we can do it unconditionally... */
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_real return %d\n", 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;
//sp: if (child->sp)
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) & 0xff;
free(argv_expanded);
restore_redirects(squirrel);
debug_printf_exec("run_pipe_real return %d\n", rcode);
return rcode;
}
}
#endif
}
/* Going to fork a child per each pipe member */
pi->running_progs = 0;
/* Disable job control signals for shell (parent) and
* for initial child code after fork */
set_jobctrl_sighandler(SIG_IGN);
for (i = 0; i < pi->num_progs; i++) {
child = &(pi->progs[i]);
if (child->argv)
debug_printf_exec(": pipe member '%s' '%s'...\n", child->argv[0], child->argv[1]);
else
debug_printf_exec(": pipe member with no argv\n");
/* pipes are inserted between pairs of commands */
if ((i + 1) < pi->num_progs) {
pipe(pipefds);
nextout = pipefds[1];
} else {
nextout = 1;
pipefds[0] = -1;
}
/* XXX test for failed fork()? */
#if BB_MMU
child->pid = fork();
#else
child->pid = vfork();
#endif
if (!child->pid) { /* child */
/* Every child adds itself to new process group
* with pgid == pid of first child in pipe */
#if ENABLE_HUSH_JOB
if (run_list_level == 1 && interactive_fd) {
/* Don't do pgrp restore anymore on fatal signals */
set_fatal_sighandler(SIG_DFL);
if (pi->pgrp < 0) /* true for 1st process only */
pi->pgrp = getpid();
if (setpgid(0, pi->pgrp) == 0 && pi->followup != PIPE_BG) {
/* We do it in *every* child, not just first,
* to avoid races */
tcsetpgrp(interactive_fd, pi->pgrp);
}
}
#endif
/* in non-interactive case fatal sigs are already SIG_DFL */
xmove_fd(nextin, 0);
xmove_fd(nextout, 1);
if (pipefds[0] != -1) {
close(pipefds[0]); /* opposite end of our output pipe */
}
/* 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(child);
}
pi->running_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 (nextin != 0)
close(nextin);
if (nextout != 1)
close(nextout);
/* If there isn't another process, nextin is garbage
but it doesn't matter */
nextin = pipefds[0];
}
debug_printf_exec("run_pipe_real return -1\n");
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_real(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 save_num_progs;
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;
reserved_style skip_more_for_this_rword = RES_XXXX;
debug_printf_exec("run_list_real 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_real 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: not followed by IN */
debug_printf_exec("run_list_real 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(SIGTSTP, handler_ctrl_z);
signal(SIGINT, handler_ctrl_c);
}
#endif
for (; pi; pi = flag_restore ? rpipe : pi->next) {
rword = pi->res_word;
#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 */
for_list = expand_strvec_to_strvec(pi->next->progs->argv);
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;
save_num_progs = pi->num_progs; /* save number of programs */
debug_printf_exec(": run_pipe_real with %d members\n", pi->num_progs);
rcode = run_pipe_real(pi);
if (rcode != -1) {
/* We only ran a builtin: rcode was set by the return value
* of run_pipe_real(), 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
/* Paranoia, just "interactive_fd" should be enough? */
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;
pi->num_progs = save_num_progs; /* restore number of programs */
#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_real 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->type].descrip);
if (r->dup == -1) {
/* guard against the case >$FOO, where foo is unset or blank */
if (r->glob_word) {
debug_printf_clean(" %s\n", r->glob_word[0]);
free_strings(r->glob_word);
r->glob_word = 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) {
debug_printf_clean("%s pipe reserved mode %d\n", indenter(indent), pi->res_word);
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_list(struct pipe *pi)
{
int rcode = 0;
debug_printf_exec("run_list entered\n");
if (fake_mode == 0) {
debug_printf_exec(": run_list_real with %d members\n", pi->num_progs);
rcode = run_list_real(pi);
}
/* free_pipe_list has the side effect of clearing memory.
* In the long run that function can be merged with run_list_real,
* but doing that now would hobble the debugging effort. */
free_pipe_list(pi, 0);
debug_printf_exec("run_list return %d\n", rcode);
return rcode;
}
/* Whoever decided to muck with glob internal data is AN IDIOT! */
/* uclibc happily changed the way it works (and it has rights to do so!),
all hell broke loose (SEGVs) */
/* The API for glob is arguably broken. This routine pushes a non-matching
* string into the output structure, removing non-backslashed backslashes.
* If someone can prove me wrong, by performing this function within the
* original glob(3) api, feel free to rewrite this routine into oblivion.
* XXX broken if the last character is '\\', check that before calling.
*/
static char **globhack(const char *src, char **strings)
{
int cnt;
const char *s;
char *v, *dest;
for (cnt = 1, s = src; s && *s; s++) {
if (*s == '\\') s++;
cnt++;
}
v = dest = xmalloc(cnt);
for (s = src; s && *s; s++, dest++) {
if (*s == '\\') s++;
*dest = *s;
}
*dest = '\0';
return add_string_to_strings(strings, v);
}
/* XXX broken if the last character is '\\', check that before calling */
static int glob_needed(const char *s)
{
for (; *s; s++) {
if (*s == '\\')
s++;
if (strchr("*[?", *s))
return 1;
}
return 0;
}
static int xglob(o_string *dest, char ***pglob)
{
/* short-circuit for null word */
/* we can code this better when the debug_printf's are gone */
if (dest->length == 0) {
if (dest->nonnull) {
/* bash man page calls this an "explicit" null */
*pglob = globhack(dest->data, *pglob);
}
return 0;
}
if (glob_needed(dest->data)) {
glob_t globdata;
int gr;
memset(&globdata, 0, sizeof(globdata));
gr = glob(dest->data, 0, NULL, &globdata);
debug_printf("glob returned %d\n", gr);
if (gr == GLOB_NOSPACE)
bb_error_msg_and_die("out of memory during glob");
if (gr == GLOB_NOMATCH) {
debug_printf("globhack returned %d\n", gr);
/* quote removal, or more accurately, backslash removal */
*pglob = globhack(dest->data, *pglob);
globfree(&globdata);
return 0;
}
if (gr != 0) { /* GLOB_ABORTED ? */
bb_error_msg("glob(3) error %d", gr);
}
if (globdata.gl_pathv && globdata.gl_pathv[0])
*pglob = add_strings_to_strings(1, *pglob, globdata.gl_pathv);
globfree(&globdata);
return gr;
}
*pglob = globhack(dest->data, *pglob);
return 0;
}
/* 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 $VAR).
* This new list is allocated as a single malloc block.
* NULL-terminated list of char* pointers is at the beginning of it,
* followed by strings themself.
* Caller can deallocate entire list by single free(list). */
/* Helpers first:
* count_XXX estimates size of the block we need. It's okay
* to over-estimate sizes a bit, if it makes code simpler */
static int count_ifs(const char *str)
{
int cnt = 0;
debug_printf_expand("count_ifs('%s') ifs='%s'", str, ifs);
while (1) {
str += strcspn(str, ifs);
if (!*str) break;
str++; /* str += strspn(str, ifs); */
cnt++; /* cnt += strspn(str, ifs); - but this code is larger */
}
debug_printf_expand(" return %d\n", cnt);
return cnt;
}
static void count_var_expansion_space(int *countp, int *lenp, char *arg)
{
char first_ch;
int i;
int len = *lenp;
int count = *countp;
const char *val;
char *p;
while ((p = strchr(arg, SPECIAL_VAR_SYMBOL))) {
len += p - arg;
arg = ++p;
p = strchr(p, SPECIAL_VAR_SYMBOL);
first_ch = arg[0];
switch (first_ch & 0x7f) {
/* high bit in 1st_ch indicates that var is double-quoted */
case '$': /* pid */
case '!': /* bg pid */
case '?': /* exitcode */
case '#': /* argc */
len += sizeof(int)*3 + 1; /* enough for int */
break;
case '*':
case '@':
for (i = 1; global_argv[i]; i++) {
len += strlen(global_argv[i]) + 1;
count++;
if (!(first_ch & 0x80))
count += count_ifs(global_argv[i]);
}
break;
default:
*p = '\0';
arg[0] = first_ch & 0x7f;
if (isdigit(arg[0])) {
i = xatoi_u(arg);
val = NULL;
if (i < global_argc)
val = global_argv[i];
} else
val = lookup_param(arg);
arg[0] = first_ch;
*p = SPECIAL_VAR_SYMBOL;
if (val) {
len += strlen(val) + 1;
if (!(first_ch & 0x80))
count += count_ifs(val);
}
}
arg = ++p;
}
len += strlen(arg) + 1;
count++;
*lenp = len;
*countp = count;
}
/* 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(char **list, int n, char **posp, const char *str)
{
char *pos = *posp;
while (1) {
int word_len = strcspn(str, ifs);
if (word_len) {
memcpy(pos, str, word_len); /* store non-ifs chars */
pos += word_len;
str += word_len;
}
if (!*str) /* EOL - do not finalize word */
break;
*pos++ = '\0';
if (n) debug_printf_expand("expand_on_ifs finalized list[%d]=%p '%s' "
"strlen=%d next=%p pos=%p\n", n-1, list[n-1], list[n-1],
strlen(list[n-1]), list[n-1] + strlen(list[n-1]) + 1, pos);
list[n++] = pos;
str += strspn(str, ifs); /* skip ifs chars */
}
*posp = pos;
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 $empty"" expands to zero words, has to expand to empty word */
static int expand_vars_to_list(char **list, int n, char **posp, char *arg, char or_mask)
{
/* or_mask is either 0 (normal case) or 0x80
* (expansion of right-hand side of assignment == 1-element expand) */
char first_ch, ored_ch;
int i;
const char *val;
char *p;
char *pos = *posp;
ored_ch = 0;
if (n) debug_printf_expand("expand_vars_to_list finalized list[%d]=%p '%s' "
"strlen=%d next=%p pos=%p\n", n-1, list[n-1], list[n-1],
strlen(list[n-1]), list[n-1] + strlen(list[n-1]) + 1, pos);
list[n++] = pos;
while ((p = strchr(arg, SPECIAL_VAR_SYMBOL))) {
memcpy(pos, arg, p - arg);
pos += (p - arg);
arg = ++p;
p = strchr(p, SPECIAL_VAR_SYMBOL);
first_ch = arg[0] | or_mask; /* forced to "quoted" if or_mask = 0x80 */
ored_ch |= first_ch;
val = NULL;
switch (first_ch & 0x7f) {
/* Highest bit in first_ch indicates that var is double-quoted */
case '$': /* pid */
/* FIXME: (echo $$) should still print pid of main shell */
val = utoa(getpid());
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 $@ */
while (global_argv[i]) {
n = expand_on_ifs(list, n, &pos, global_argv[i]);
debug_printf_expand("expand_vars_to_list: argv %d (last %d)\n", i, global_argc-1);
if (global_argv[i++][0] && global_argv[i]) {
/* this argv[] is not empty and not last:
* put terminating NUL, start new word */
*pos++ = '\0';
if (n) debug_printf_expand("expand_vars_to_list 2 finalized list[%d]=%p '%s' "
"strlen=%d next=%p pos=%p\n", n-1, list[n-1], list[n-1],
strlen(list[n-1]), list[n-1] + strlen(list[n-1]) + 1, pos);
list[n++] = pos;
}
}
} else
/* If or_mask is nonzero, we handle assignment 'a=....$@.....'
* and in this case should treat it like '$*' - see 'else...' below */
if (first_ch == ('@'|0x80) && !or_mask) { /* quoted $@ */
while (1) {
strcpy(pos, global_argv[i]);
pos += strlen(global_argv[i]);
if (++i >= global_argc)
break;
*pos++ = '\0';
if (n) debug_printf_expand("expand_vars_to_list 3 finalized list[%d]=%p '%s' "
"strlen=%d next=%p pos=%p\n", n-1, list[n-1], list[n-1],
strlen(list[n-1]), list[n-1] + strlen(list[n-1]) + 1, pos);
list[n++] = pos;
}
} else { /* quoted $*: add as one word */
while (1) {
strcpy(pos, global_argv[i]);
pos += strlen(global_argv[i]);
if (!global_argv[++i])
break;
if (ifs[0])
*pos++ = ifs[0];
}
}
break;
default:
*p = '\0';
arg[0] = first_ch & 0x7f;
if (isdigit(arg[0])) {
i = xatoi_u(arg);
val = NULL;
if (i < global_argc)
val = global_argv[i];
} else
val = lookup_param(arg);
arg[0] = first_ch;
*p = SPECIAL_VAR_SYMBOL;
if (!(first_ch & 0x80)) { /* unquoted $VAR */
if (val) {
n = expand_on_ifs(list, n, &pos, val);
val = NULL;
}
} /* else: quoted $VAR, val will be appended at pos */
}
if (val) {
strcpy(pos, val);
pos += strlen(val);
}
arg = ++p;
}
debug_printf_expand("expand_vars_to_list adding tail '%s' at %p\n", arg, pos);
strcpy(pos, arg);
pos += strlen(arg) + 1;
if (pos == list[n-1] + 1) { /* expansion is empty */
if (!(ored_ch & 0x80)) { /* all vars were not quoted... */
debug_printf_expand("expand_vars_to_list list[%d] empty, going back\n", n);
pos--;
n--;
}
}
*posp = pos;
return n;
}
static char **expand_variables(char **argv, char or_mask)
{
int n;
int count = 1;
int len = 0;
char *pos, **v, **list;
v = argv;
if (!*v) debug_printf_expand("count_var_expansion_space: "
"argv[0]=NULL count=%d len=%d alloc_space=%d\n",
count, len, sizeof(char*) * count + len);
while (*v) {
count_var_expansion_space(&count, &len, *v);
debug_printf_expand("count_var_expansion_space: "
"'%s' count=%d len=%d alloc_space=%d\n",
*v, count, len, sizeof(char*) * count + len);
v++;
}
len += sizeof(char*) * count; /* total to alloc */
list = xmalloc(len);
pos = (char*)(list + count);
debug_printf_expand("list=%p, list[0] should be %p\n", list, pos);
n = 0;
v = argv;
while (*v)
n = expand_vars_to_list(list, n, &pos, *v++, or_mask);
if (n) debug_printf_expand("finalized list[%d]=%p '%s' "
"strlen=%d next=%p pos=%p\n", n-1, list[n-1], list[n-1],
strlen(list[n-1]), list[n-1] + strlen(list[n-1]) + 1, pos);
list[n] = NULL;
#ifdef DEBUG_EXPAND
{
int m = 0;
while (m <= n) {
debug_printf_expand("list[%d]=%p '%s'\n", m, list[m], list[m]);
m++;
}
debug_printf_expand("used_space=%d\n", pos - (char*)list);
}
#endif
if (ENABLE_HUSH_DEBUG)
if (pos - (char*)list > len)
bb_error_msg_and_die("BUG in varexp");
return list;
}
static char **expand_strvec_to_strvec(char **argv)
{
return expand_variables(argv, 0);
}
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 (ENABLE_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;
}
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 (ENABLE_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;
}
/* This is 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;
}
}
static int is_assignment(const char *s)
{
if (!s || !isalpha(*s))
return 0;
s++;
while (isalnum(*s) || *s == '_')
s++;
return *s == '=';
}
/* 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->glob_word = NULL; */
if (last_redir) {
last_redir->next = redir;
} else {
child->redirects = redir;
}
redir->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->num_progs = 0;*/
/*pi->progs = NULL;*/
/*pi->next = NULL;*/
/*pi->followup = 0; invalid */
if (RES_NONE)
pi->res_word = RES_NONE;
return pi;
}
static void initialize_context(struct p_context *ctx)
{
ctx->child = NULL;
ctx->pipe = ctx->list_head = new_pipe();
ctx->pending_redirect = NULL;
ctx->res_w = RES_NONE;
//only ctx->parse_type is not touched... is this intentional?
ctx->old_flag = 0;
ctx->stack = NULL;
done_command(ctx); /* creates the memory for working child */
}
/* normal return is 0
* if a reserved word is found, and processed, return 1
* should handle if, then, elif, else, fi, for, while, until, do, done.
* case, function, and select are obnoxious, save those for later.
*/
#if ENABLE_HUSH_IF || ENABLE_HUSH_LOOPS
static int reserved_word(o_string *dest, struct p_context *ctx)
{
struct reserved_combo {
char literal[7];
unsigned char code;
int flag;
};
/* 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
{ "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(dest->data, r->literal) != 0)
continue;
debug_printf("found reserved word %s, code %d\n", r->literal, r->code);
if (r->flag & FLAG_START) {
struct p_context *new;
debug_printf("push stack\n");
#if ENABLE_HUSH_LOOPS
if (ctx->res_w == RES_IN || ctx->res_w == RES_FOR) {
syntax("malformed for"); /* example: 'for if' */
ctx->res_w = RES_SNTX;
b_reset(dest);
return 1;
}
#endif
new = xmalloc(sizeof(*new));
*new = *ctx; /* physical copy */
initialize_context(ctx);
ctx->stack = new;
} else if (ctx->res_w == RES_NONE || !(ctx->old_flag & (1 << r->code))) {
syntax(NULL);
ctx->res_w = RES_SNTX;
b_reset(dest);
return 1;
}
ctx->res_w = r->code;
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);
}
b_reset(dest);
return 1;
}
return 0;
}
#else
#define reserved_word(dest, ctx) ((int)0)
#endif
/* Normal return is 0.
* Syntax or xglob errors return 1. */
static int done_word(o_string *dest, struct p_context *ctx)
{
struct child_prog *child = ctx->child;
char ***glob_target;
int gr;
debug_printf_parse("done_word entered: '%s' %p\n", dest->data, child);
if (dest->length == 0 && !dest->nonnull) {
debug_printf_parse("done_word return 0: true null, ignored\n");
return 0;
}
if (ctx->pending_redirect) {
glob_target = &ctx->pending_redirect->glob_word;
} else {
if (child->group) {
syntax(NULL);
debug_printf_parse("done_word return 1: syntax error, groups and arglists don't mix\n");
return 1;
}
if (!child->argv && (ctx->parse_type & PARSEFLAG_SEMICOLON)) {
debug_printf_parse(": checking '%s' for reserved-ness\n", dest->data);
if (reserved_word(dest, ctx)) {
debug_printf_parse("done_word return %d\n", (ctx->res_w == RES_SNTX));
return (ctx->res_w == RES_SNTX);
}
}
glob_target = &child->argv;
}
gr = xglob(dest, glob_target);
if (gr != 0) {
debug_printf_parse("done_word return 1: xglob returned %d\n", gr);
return 1;
}
b_reset(dest);
if (ctx->pending_redirect) {
/* NB: don't free_strings(ctx->pending_redirect->glob_word) here */
if (ctx->pending_redirect->glob_word
&& ctx->pending_redirect->glob_word[0]
&& ctx->pending_redirect->glob_word[1]
) {
/* more than one word resulted from globbing redir */
ctx->pending_redirect = NULL;
bb_error_msg("ambiguous redirect");
debug_printf_parse("done_word return 1: ambiguous redirect\n");
return 1;
}
ctx->pending_redirect = NULL;
}
#if ENABLE_HUSH_LOOPS
if (ctx->res_w == RES_FOR) {
done_word(dest, ctx);
done_pipe(ctx, PIPE_SEQ);
}
#endif
debug_printf_parse("done_word return 0\n");
return 0;
}
/* 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->redirects = NULL;*/
/*child->argv = NULL;*/
/*child->is_stopped = 0;*/
/*child->group = NULL;*/
child->family = pi;
//sp: /*child->sp = 0;*/
//pt: child->parse_type = ctx->parse_type;
ctx->child = child;
/* but ctx->pipe and ctx->list_head remain unchanged */
return pi->num_progs; /* used only for 0/nonzero check */
}
static int done_pipe(struct p_context *ctx, pipe_style type)
{
struct pipe *new_p;
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;
ctx->pipe->res_word = ctx->res_w;
/* 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. */
if (not_null) {
new_p = new_pipe();
ctx->pipe->next = new_p;
ctx->pipe = new_p;
ctx->child = NULL;
done_command(ctx); /* set up new pipe to accept commands */
}
debug_printf_parse("done_pipe return 0\n");
return 0;
}
/* 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.
* returns 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 = b_peek(input);
if (ch != '&') return -1;
b_getch(input); /* get the & */
ch = b_peek(input);
if (ch == '-') {
b_getch(input);
return -3; /* "-" represents "close me" */
}
while (isdigit(ch)) {
d = d*10 + (ch-'0');
ok = 1;
b_getch(input);
ch = b_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;
}
}
/* reuse num (and save an int) */
num = atoi(o->data);
b_reset(o);
return num;
}
#if ENABLE_HUSH_TICK
/* NB: currently disabled on NOMMU */
static FILE *generate_stream_from_list(struct pipe *head)
{
FILE *pf;
int pid, channel[2];
xpipe(channel);
pid = fork();
if (pid < 0) {
bb_perror_msg_and_die("fork");
} else if (pid == 0) {
close(channel[0]);
if (channel[1] != 1) {
dup2(channel[1], 1);
close(channel[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);
_exit(run_list_real(head)); /* leaks memory */
}
close(channel[1]);
pf = fdopen(channel[0], "r");
return pf;
}
/* Return code is exit status of the process that is run. */
static int process_command_subs(o_string *dest, struct p_context *ctx,
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);
b_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 = b_getch(&pipe_str)) != EOF) {
if (ch == '\n') {
eol_cnt++;
continue;
}
while (eol_cnt) {
b_addqchr(dest, '\n', dest->o_quote);
eol_cnt--;
}
b_addqchr(dest, ch, dest->o_quote);
}
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, 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);
//vda: err chk?
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;
}
/* return code: 0 for OK, 1 for syntax error */
static int handle_dollar(o_string *dest, struct p_context *ctx, struct in_str *input)
{
int ch = b_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)) {
b_addchr(dest, SPECIAL_VAR_SYMBOL);
//sp: ctx->child->sp++;
while (1) {
debug_printf_parse(": '%c'\n", ch);
b_getch(input);
b_addchr(dest, ch | quote_mask);
quote_mask = 0;
ch = b_peek(input);
if (!isalnum(ch) && ch != '_')
break;
}
b_addchr(dest, SPECIAL_VAR_SYMBOL);
} else if (isdigit(ch)) {
make_one_char_var:
b_addchr(dest, SPECIAL_VAR_SYMBOL);
//sp: ctx->child->sp++;
debug_printf_parse(": '%c'\n", ch);
b_getch(input);
b_addchr(dest, ch | quote_mask);
b_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 '{':
b_addchr(dest, SPECIAL_VAR_SYMBOL);
//sp: ctx->child->sp++;
b_getch(input);
/* XXX maybe someone will try to escape the '}' */
while (1) {
ch = b_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);
b_addchr(dest, ch | quote_mask);
quote_mask = 0;
}
b_addchr(dest, SPECIAL_VAR_SYMBOL);
break;
#if ENABLE_HUSH_TICK
case '(':
b_getch(input);
process_command_subs(dest, ctx, input, ")");
break;
#endif
case '-':
case '_':
/* still unhandled, but should be eventually */
bb_error_msg("unhandled syntax: $%c", ch);
return 1;
break;
default:
b_addqchr(dest, '$', dest->o_quote);
}
debug_printf_parse("handle_dollar return 0\n");
return 0;
}
/* return code is 0 for normal exit, 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 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 = b_getch(input);
if (ch != EOF) {
m = charmap[ch];
if (ch != '\n')
next = b_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 && dest->o_quote)
) {
if (ch == EOF) {
syntax("unterminated \"");
debug_printf_parse("parse_stream return 1: unterminated \"\n");
return 1;
}
b_addqchr(dest, ch, dest->o_quote);
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 && strchr(end_trigger, ch))
&& !dest->o_quote && ctx->res_w == RES_NONE
) {
debug_printf_parse("parse_stream return 0: end_trigger char found\n");
return 0;
}
if (m == CHAR_IFS)
continue;
switch (ch) {
case '#':
if (dest->length == 0 && !dest->o_quote) {
while (1) {
ch = b_peek(input);
if (ch == EOF || ch == '\n')
break;
b_getch(input);
}
} else {
b_addqchr(dest, ch, dest->o_quote);
}
break;
case '\\':
if (next == EOF) {
syntax("\\<eof>");
debug_printf_parse("parse_stream return 1: \\<eof>\n");
return 1;
}
b_addqchr(dest, '\\', dest->o_quote);
b_addqchr(dest, b_getch(input), dest->o_quote);
break;
case '$':
if (handle_dollar(dest, ctx, 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 = b_getch(input);
if (ch == EOF || ch == '\'')
break;
b_addchr(dest, ch);
}
if (ch == EOF) {
syntax("unterminated '");
debug_printf_parse("parse_stream return 1: unterminated '\n");
return 1;
}
break;
case '"':
dest->nonnull = 1;
dest->o_quote ^= 1; /* invert */
break;
#if ENABLE_HUSH_TICK
case '`':
process_command_subs(dest, ctx, input, "`");
break;
#endif
case '>':
redir_fd = redirect_opt_num(dest);
done_word(dest, ctx);
redir_style = REDIRECT_OVERWRITE;
if (next == '>') {
redir_style = REDIRECT_APPEND;
b_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;
b_getch(input);
} else if (next == '>') {
redir_style = REDIRECT_IO;
b_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 == '&') {
b_getch(input);
done_pipe(ctx, PIPE_AND);
} else {
done_pipe(ctx, PIPE_BG);
}
break;
case '|':
done_word(dest, ctx);
if (next == '|') {
b_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 '}':
syntax("unexpected }"); /* Proper use of this character is caught by end_trigger */
debug_printf_parse("parse_stream return 1: unexpected '}'\n");
return 1;
default:
if (ENABLE_HUSH_DEBUG)
bb_error_msg_and_die("BUG: unexpected %c\n", ch);
}
}
/* Complain if quote? No, maybe we just finished a command substitution
* that was quoted. Example:
* $ echo "`cat foo` plus more"
* and we just got the EOF generated by the subshell that ran "cat foo"
* The only real complaint is if we got an EOF when end_trigger != NULL,
* that is, we were really supposed to get end_trigger, and never got
* one before the EOF. Can't use the standard "syntax error" return code,
* so that parse_stream_outer can distinguish the EOF and exit smoothly. */
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 {
ctx.parse_type = parse_flag;
initialize_context(&ctx);
update_charmap();
if (!(parse_flag & PARSEFLAG_SEMICOLON) || (parse_flag & PARSEFLAG_REPARSING))
set_in_charmap(";$&|", CHAR_ORDINARY);
#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 (rcode != 1 && ctx.old_flag != 0) {
syntax(NULL);
}
if (rcode != 1 && 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_list\n");
run_list(ctx.list_head);
} else {
if (ctx.old_flag != 0) {
free(ctx.stack);
b_reset(&temp);
}
temp.nonnull = 0;
temp.o_quote = 0;
inp->p = NULL;
free_pipe_list(ctx.list_head, 0);
}
b_free(&temp);
} while (rcode != -1 && !(parse_flag & PARSEFLAG_EXIT_FROM_LOOP)); /* loop on syntax errors, return on EOF */
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, PARSEFLAG_SEMICOLON);
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;
PTR_TO_GLOBALS = xzalloc(sizeof(G));
/* 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, PARSEFLAG_SEMICOLON);
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) {
/* Looks like they want an interactive shell */
setup_job_control();
/* Make xfuncs do cleanup on exit */
die_sleep = -1; /* flag */
// FIXME: should we reset die_sleep = 0 whereever we fork?
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;
}
}
#endif
if (argv[optind] == NULL) {
opt = parse_and_run_file(stdin);
goto final_return;
}
debug_printf("\nrunning script '%s'\n", argv[optind]);
global_argv = argv + optind;
global_argc = argc - optind;
input = xfopen(argv[optind], "r");
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