util-linux/script.c - busybox - Git at Google

 /* vi: set sw=4 ts=4: */
 /*
  * script implementation for busybox
  *
  * pascal.bellard@ads-lu.com
  *
  * Based on code from util-linux v 2.12r
  * Copyright (c) 1980
  * The Regents of the University of California.  All rights reserved.
  *
  * Licensed under GPLv2 or later, see file LICENSE in this source tree.
  */
 //config:config SCRIPT
 //config:	bool "script (8.6 kb)"
 //config:	default y
 //config:	help
 //config:	The script makes typescript of terminal session.

 //applet:IF_SCRIPT(APPLET(script, BB_DIR_USR_BIN, BB_SUID_DROP))

 //kbuild:lib-$(CONFIG_SCRIPT) += script.o

 //usage:#define script_trivial_usage
 //usage:       "[-afq] [-t[FILE]] [-c PROG] [OUTFILE]"
 //usage:#define script_full_usage "\n\n"
 //usage:       "Default OUTFILE is 'typescript'"
 //usage:     "\n"
 //usage:     "\n	-a	Append output"
 //usage:     "\n	-c PROG	Run PROG, not shell"
 /* Accepted but has no effect (we never buffer output) */
 /*//usage:     "\n	-f	Flush output after each write"*/
 //usage:     "\n	-q	Quiet"
 //usage:     "\n	-t[FILE] Send timing to stderr or FILE"

 //util-linux-2.28:
 //-e: return exit code of the child

 //FYI (reported as bbox bug #2749):
 // > script -q -c 'echo -e -n "1\n2\n3\n"' /dev/null </dev/null >123.txt
 // > The output file on full-blown ubuntu system contains 6 bytes.
 // > Output on Busybox system (arm-linux) contains extra '\r' byte in each line.
 //however, in my test, "script" from util-linux-2.28 seems to also add '\r' bytes.

 #include "libbb.h"
 #include "common_bufsiz.h"

 int script_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
 int script_main(int argc UNUSED_PARAM, char **argv)
 {
 	int opt;
 	int mode;
 	int child_pid;
 	int attr_ok; /* NB: 0: ok */
 	int winsz_ok;
 	int pty;
 	char pty_line[GETPTY_BUFSIZE];
 	struct termios tt, rtt;
 	struct winsize win;
 	FILE *timing_fp;
 	const char *str_t = NULL;
 	const char *fname = "typescript";
 	const char *shell;
 	char shell_opt[] = "-i";
 	char *shell_arg = NULL;
 	enum {
 		OPT_a = (1 << 0),
 		OPT_c = (1 << 1),
 		OPT_f = (1 << 2),
 		OPT_q = (1 << 3),
 		OPT_t = (1 << 4),
 	};

 #if ENABLE_LONG_OPTS
 	static const char script_longopts[] ALIGN1 =
 		"append\0"  No_argument       "a"
 		"command\0" Required_argument "c"
 		"flush\0"   No_argument       "f"
 		"quiet\0"   No_argument       "q"
 		"timing\0"  Optional_argument "t"
 		;
 #endif

 	opt = getopt32long(argv, "^" "ac:fqt::" "\0" "?1"/* max one arg */,
 				script_longopts,
 				&shell_arg, &str_t
 	);
 	//argc -= optind;
 	argv += optind;
 	if (argv[0]) {
 		fname = argv[0];
 	}
 	mode = O_CREAT|O_TRUNC|O_WRONLY;
 	if (opt & OPT_a) {
 		mode = O_CREAT|O_APPEND|O_WRONLY;
 	}
 	if (opt & OPT_c) {
 		shell_opt[1] = 'c';
 	}
 	if (!(opt & OPT_q)) {
 		printf("Script started, file is %s\n", fname);
 	}
 	timing_fp = stderr;
 	if (str_t) {
 		timing_fp = xfopen_for_write(str_t);
 	}

 	shell = get_shell_name();

 	/* Some people run "script ... 0>&-".
 	 * Our code assumes that STDIN_FILENO != pty.
 	 * Ensure STDIN_FILENO is not closed:
 	 */
 	bb_sanitize_stdio();

 	pty = xgetpty(pty_line);

 	/* get current stdin's tty params */
 	attr_ok = tcgetattr(0, &tt);
 	winsz_ok = ioctl(0, TIOCGWINSZ, (char *)&win);

 	rtt = tt;
 	cfmakeraw(&rtt);
 	rtt.c_lflag &= ~ECHO;
 	tcsetattr(0, TCSAFLUSH, &rtt);

 	/* "script" from util-linux exits when child exits,
 	 * we wouldn't wait for EOF from slave pty
 	 * (output may be produced by grandchildren of child) */
 	signal(SIGCHLD, record_signo);

 	/* TODO: SIGWINCH? pass window size changes down to slave? */

 	child_pid = xvfork();

 	if (child_pid) {
 		/* parent */
 		struct pollfd pfd[2];
 		int outfd, count, loop;
 		double oldtime = time(NULL);
 		smallint fd_count = 2;

 #define buf bb_common_bufsiz1
 		setup_common_bufsiz();

 		outfd = xopen(fname, mode);
 		pfd[0].fd = pty;
 		pfd[0].events = POLLIN;
 		pfd[1].fd = STDIN_FILENO;
 		pfd[1].events = POLLIN;
 		ndelay_on(pty); /* this descriptor is not shared, can do this */
 		/* ndelay_on(STDIN_FILENO); - NO, stdin can be shared! Pity :( */

 		/* copy stdin to pty master input,
 		 * copy pty master output to stdout and file */
 		/* TODO: don't use full_write's, use proper write buffering */
 		while (fd_count && !bb_got_signal) {
 			/* not safe_poll! we want SIGCHLD to EINTR poll */
 			if (poll(pfd, fd_count, -1) < 0 && errno != EINTR) {
 				/* If child exits too quickly, we may get EIO:
 				 * for example, try "script -c true" */
 				break;
 			}
 			if (pfd[0].revents) {
 				errno = 0;
 				count = safe_read(pty, buf, COMMON_BUFSIZE);
 				if (count <= 0 && errno != EAGAIN) {
 					/* err/eof from pty: exit */
 					goto restore;
 				}
 				if (count > 0) {
 					if (opt & OPT_t) {
 						struct timeval tv;
 						double newtime;

 						gettimeofday(&tv, NULL);
 						newtime = tv.tv_sec + (double) tv.tv_usec / 1000000;
 						fprintf(timing_fp, "%f %u\n", newtime - oldtime, count);
 						oldtime = newtime;
 					}
 					full_write(STDOUT_FILENO, buf, count);
 					full_write(outfd, buf, count);
 					// If we'd be using (buffered) FILE i/o, we'd need this:
 					//if (opt & OPT_f) {
 					//	fflush(outfd);
 					//}
 				}
 			}
 			if (pfd[1].revents) {
 				count = safe_read(STDIN_FILENO, buf, COMMON_BUFSIZE);
 				if (count <= 0) {
 					/* err/eof from stdin: don't read stdin anymore */
 					pfd[1].revents = 0;
 					fd_count--;
 				} else {
 					full_write(pty, buf, count);
 				}
 			}
 		}
 		/* If loop was exited because SIGCHLD handler set bb_got_signal,
 		 * there still can be some buffered output. But dont loop forever:
 		 * we won't pump orphaned grandchildren's output indefinitely.
 		 * Testcase: running this in script:
 		 *      exec dd if=/dev/zero bs=1M count=1
 		 * must have "1+0 records in, 1+0 records out" captured too.
 		 * (util-linux's script doesn't do this. buggy :) */
 		loop = 999;
 		/* pty is in O_NONBLOCK mode, we exit as soon as buffer is empty */
 		while (--loop && (count = safe_read(pty, buf, COMMON_BUFSIZE)) > 0) {
 			full_write(STDOUT_FILENO, buf, count);
 			full_write(outfd, buf, count);
 		}
  restore:
 		if (attr_ok == 0)
 			tcsetattr(0, TCSAFLUSH, &tt);
 		if (!(opt & OPT_q))
 			printf("Script done, file is %s\n", fname);
 		return EXIT_SUCCESS;
 	}

 	/* child: make pty slave to be input, output, error; run shell */
 	close(pty); /* close pty master */
 	/* open pty slave to fd 0,1,2 */
 	close(0);
 	xopen(pty_line, O_RDWR); /* uses fd 0 */
 	xdup2(0, 1);
 	xdup2(0, 2);
 	/* copy our original stdin tty's parameters to pty */
 	if (attr_ok == 0)
 		tcsetattr(0, TCSAFLUSH, &tt);
 	if (winsz_ok == 0)
 		ioctl(0, TIOCSWINSZ, (char *)&win);
 	/* set pty as a controlling tty */
 	setsid();
 	ioctl(0, TIOCSCTTY, 0 /* 0: don't forcibly steal */);

 	/* Non-ignored signals revert to SIG_DFL on exec anyway */
 	/*signal(SIGCHLD, SIG_DFL);*/
 	execl(shell, shell, shell_opt, shell_arg, (char *) NULL);
 	bb_simple_perror_msg_and_die(shell);
 }
	/* vi: set sw=4 ts=4: */
	/*
	* script implementation for busybox
	*
	* pascal.bellard@ads-lu.com
	*
	* Based on code from util-linux v 2.12r
	* Copyright (c) 1980
	* The Regents of the University of California. All rights reserved.
	*
	* Licensed under GPLv2 or later, see file LICENSE in this source tree.
	*/
	//config:config SCRIPT
	//config: bool "script (8.6 kb)"
	//config: default y
	//config: help
	//config: The script makes typescript of terminal session.

	//applet:IF_SCRIPT(APPLET(script, BB_DIR_USR_BIN, BB_SUID_DROP))

	//kbuild:lib-$(CONFIG_SCRIPT) += script.o

	//usage:#define script_trivial_usage
	//usage: "[-afq] [-t[FILE]] [-c PROG] [OUTFILE]"
	//usage:#define script_full_usage "\n\n"
	//usage: "Default OUTFILE is 'typescript'"
	//usage: "\n"
	//usage: "\n -a Append output"
	//usage: "\n -c PROG Run PROG, not shell"
	/* Accepted but has no effect (we never buffer output) */
	///usage: "\n -f Flush output after each write"/
	//usage: "\n -q Quiet"
	//usage: "\n -t[FILE] Send timing to stderr or FILE"

	//util-linux-2.28:
	//-e: return exit code of the child

	//FYI (reported as bbox bug #2749):
	// > script -q -c 'echo -e -n "1\n2\n3\n"' /dev/null </dev/null >123.txt
	// > The output file on full-blown ubuntu system contains 6 bytes.
	// > Output on Busybox system (arm-linux) contains extra '\r' byte in each line.
	//however, in my test, "script" from util-linux-2.28 seems to also add '\r' bytes.

	#include "libbb.h"
	#include "common_bufsiz.h"

	int script_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
	int script_main(int argc UNUSED_PARAM, char **argv)
	{
	int opt;
	int mode;
	int child_pid;
	int attr_ok; /* NB: 0: ok */
	int winsz_ok;
	int pty;
	char pty_line[GETPTY_BUFSIZE];
	struct termios tt, rtt;
	struct winsize win;
	FILE *timing_fp;
	const char *str_t = NULL;
	const char *fname = "typescript";
	const char *shell;
	char shell_opt[] = "-i";
	char *shell_arg = NULL;
	enum {
	OPT_a = (1 << 0),
	OPT_c = (1 << 1),
	OPT_f = (1 << 2),
	OPT_q = (1 << 3),
	OPT_t = (1 << 4),
	};

	#if ENABLE_LONG_OPTS
	static const char script_longopts[] ALIGN1 =
	"append\0" No_argument "a"
	"command\0" Required_argument "c"
	"flush\0" No_argument "f"
	"quiet\0" No_argument "q"
	"timing\0" Optional_argument "t"
	;
	#endif

	opt = getopt32long(argv, "^" "ac:fqt::" "\0" "?1"/* max one arg */,
	script_longopts,
	&shell_arg, &str_t
	);
	//argc -= optind;
	argv += optind;
	if (argv[0]) {
	fname = argv[0];
	}
	mode = O_CREAT\|O_TRUNC\|O_WRONLY;
	if (opt & OPT_a) {
	mode = O_CREAT\|O_APPEND\|O_WRONLY;
	}
	if (opt & OPT_c) {
	shell_opt[1] = 'c';
	}
	if (!(opt & OPT_q)) {
	printf("Script started, file is %s\n", fname);
	}
	timing_fp = stderr;
	if (str_t) {
	timing_fp = xfopen_for_write(str_t);
	}

	shell = get_shell_name();

	/* Some people run "script ... 0>&-".
	* Our code assumes that STDIN_FILENO != pty.
	* Ensure STDIN_FILENO is not closed:
	*/
	bb_sanitize_stdio();

	pty = xgetpty(pty_line);

	/* get current stdin's tty params */
	attr_ok = tcgetattr(0, &tt);
	winsz_ok = ioctl(0, TIOCGWINSZ, (char *)&win);

	rtt = tt;
	cfmakeraw(&rtt);
	rtt.c_lflag &= ~ECHO;
	tcsetattr(0, TCSAFLUSH, &rtt);

	/* "script" from util-linux exits when child exits,
	* we wouldn't wait for EOF from slave pty
	* (output may be produced by grandchildren of child) */
	signal(SIGCHLD, record_signo);

	/* TODO: SIGWINCH? pass window size changes down to slave? */

	child_pid = xvfork();

	if (child_pid) {
	/* parent */
	struct pollfd pfd[2];
	int outfd, count, loop;
	double oldtime = time(NULL);
	smallint fd_count = 2;

	#define buf bb_common_bufsiz1
	setup_common_bufsiz();

	outfd = xopen(fname, mode);
	pfd[0].fd = pty;
	pfd[0].events = POLLIN;
	pfd[1].fd = STDIN_FILENO;
	pfd[1].events = POLLIN;
	ndelay_on(pty); /* this descriptor is not shared, can do this */
	/* ndelay_on(STDIN_FILENO); - NO, stdin can be shared! Pity :( */

	/* copy stdin to pty master input,
	* copy pty master output to stdout and file */
	/* TODO: don't use full_write's, use proper write buffering */
	while (fd_count && !bb_got_signal) {
	/* not safe_poll! we want SIGCHLD to EINTR poll */
	if (poll(pfd, fd_count, -1) < 0 && errno != EINTR) {
	/* If child exits too quickly, we may get EIO:
	* for example, try "script -c true" */
	break;
	}
	if (pfd[0].revents) {
	errno = 0;
	count = safe_read(pty, buf, COMMON_BUFSIZE);
	if (count <= 0 && errno != EAGAIN) {
	/* err/eof from pty: exit */
	goto restore;
	}
	if (count > 0) {
	if (opt & OPT_t) {
	struct timeval tv;
	double newtime;

	gettimeofday(&tv, NULL);
	newtime = tv.tv_sec + (double) tv.tv_usec / 1000000;
	fprintf(timing_fp, "%f %u\n", newtime - oldtime, count);
	oldtime = newtime;
	}
	full_write(STDOUT_FILENO, buf, count);
	full_write(outfd, buf, count);
	// If we'd be using (buffered) FILE i/o, we'd need this:
	//if (opt & OPT_f) {
	// fflush(outfd);
	//}
	}
	}
	if (pfd[1].revents) {
	count = safe_read(STDIN_FILENO, buf, COMMON_BUFSIZE);
	if (count <= 0) {
	/* err/eof from stdin: don't read stdin anymore */
	pfd[1].revents = 0;
	fd_count--;
	} else {
	full_write(pty, buf, count);
	}
	}
	}
	/* If loop was exited because SIGCHLD handler set bb_got_signal,
	* there still can be some buffered output. But dont loop forever:
	* we won't pump orphaned grandchildren's output indefinitely.
	* Testcase: running this in script:
	* exec dd if=/dev/zero bs=1M count=1
	* must have "1+0 records in, 1+0 records out" captured too.
	* (util-linux's script doesn't do this. buggy :) */
	loop = 999;
	/* pty is in O_NONBLOCK mode, we exit as soon as buffer is empty */
	while (--loop && (count = safe_read(pty, buf, COMMON_BUFSIZE)) > 0) {
	full_write(STDOUT_FILENO, buf, count);
	full_write(outfd, buf, count);
	}
	restore:
	if (attr_ok == 0)
	tcsetattr(0, TCSAFLUSH, &tt);
	if (!(opt & OPT_q))
	printf("Script done, file is %s\n", fname);
	return EXIT_SUCCESS;
	}

	/* child: make pty slave to be input, output, error; run shell */
	close(pty); /* close pty master */
	/* open pty slave to fd 0,1,2 */
	close(0);
	xopen(pty_line, O_RDWR); /* uses fd 0 */
	xdup2(0, 1);
	xdup2(0, 2);
	/* copy our original stdin tty's parameters to pty */
	if (attr_ok == 0)
	tcsetattr(0, TCSAFLUSH, &tt);
	if (winsz_ok == 0)
	ioctl(0, TIOCSWINSZ, (char *)&win);
	/* set pty as a controlling tty */
	setsid();
	ioctl(0, TIOCSCTTY, 0 /* 0: don't forcibly steal */);

	/* Non-ignored signals revert to SIG_DFL on exec anyway */
	/signal(SIGCHLD, SIG_DFL);/
	execl(shell, shell, shell_opt, shell_arg, (char *) NULL);
	bb_simple_perror_msg_and_die(shell);
	}