diff options
Diffstat (limited to 'util-linux/script.c')
| -rw-r--r-- | util-linux/script.c | 186 |
1 files changed, 186 insertions, 0 deletions
diff --git a/util-linux/script.c b/util-linux/script.c new file mode 100644 index 0000000..2e103fd --- /dev/null +++ b/util-linux/script.c @@ -0,0 +1,186 @@ +/* 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 tarball for details. + */ + +#include "libbb.h" + +static smallint fd_count = 2; + +static void handle_sigchld(int sig UNUSED_PARAM) +{ + fd_count = 0; +} + +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; + const char *fname = "typescript"; + const char *shell; + char shell_opt[] = "-i"; + char *shell_arg = NULL; + +#if ENABLE_GETOPT_LONG + static const char getopt_longopts[] ALIGN1 = + "append\0" No_argument "a" + "command\0" Required_argument "c" + "flush\0" No_argument "f" + "quiet\0" No_argument "q" + ; + + applet_long_options = getopt_longopts; +#endif + opt_complementary = "?1"; /* max one arg */ + opt = getopt32(argv, "ac:fq", &shell_arg); + //argc -= optind; + argv += optind; + if (argv[0]) { + fname = argv[0]; + } + mode = O_CREAT|O_TRUNC|O_WRONLY; + if (opt & 1) { + mode = O_CREAT|O_APPEND|O_WRONLY; + } + if (opt & 2) { + shell_opt[1] = 'c'; + } + if (!(opt & 8)) { /* not -q */ + printf("Script started, file is %s\n", fname); + } + shell = getenv("SHELL"); + if (shell == NULL) { + shell = DEFAULT_SHELL; + } + + 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, handle_sigchld); + + /* TODO: SIGWINCH? pass window size changes down to slave? */ + + child_pid = vfork(); + if (child_pid < 0) { + bb_perror_msg_and_die("vfork"); + } + + if (child_pid) { + /* parent */ +#define buf bb_common_bufsiz1 + struct pollfd pfd[2]; + int outfd, count, loop; + + outfd = xopen(fname, mode); + pfd[0].fd = pty; + pfd[0].events = POLLIN; + pfd[1].fd = 0; + pfd[1].events = POLLIN; + ndelay_on(pty); /* this descriptor is not shared, can do this */ + /* ndelay_on(0); - 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) { + /* 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, sizeof(buf)); + if (count <= 0 && errno != EAGAIN) { + /* err/eof from pty: exit */ + goto restore; + } + if (count > 0) { + full_write(STDOUT_FILENO, buf, count); + full_write(outfd, buf, count); + if (opt & 4) { /* -f */ + fsync(outfd); + } + } + } + if (pfd[1].revents) { + count = safe_read(STDIN_FILENO, buf, sizeof(buf)); + 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 fd_count to 0, + * there still can be some buffered output. But not 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, sizeof(buf))) > 0) { + full_write(STDOUT_FILENO, buf, count); + full_write(outfd, buf, count); + } + restore: + if (attr_ok == 0) + tcsetattr(0, TCSAFLUSH, &tt); + if (!(opt & 8)) /* not -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, NULL); + bb_simple_perror_msg_and_die(shell); +} |