1 /* vi: set sw=4 ts=4: */
3 * script implementation for busybox
5 * pascal.bellard@ads-lu.com
7 * Based on code from util-linux v 2.12r
9 * The Regents of the University of California. All rights reserved.
11 * Licensed under GPLv2 or later, see file License in this tarball for details.
16 static smallint fd_count = 2;
18 static void handle_sigchld(int sig UNUSED_PARAM)
23 int script_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
24 int script_main(int argc UNUSED_PARAM, char **argv)
29 int attr_ok; /* NB: 0: ok */
32 char pty_line[GETPTY_BUFSIZE];
33 struct termios tt, rtt;
35 const char *fname = "typescript";
37 char shell_opt[] = "-i";
38 char *shell_arg = NULL;
40 #if ENABLE_GETOPT_LONG
41 static const char getopt_longopts[] ALIGN1 =
42 "append\0" No_argument "a"
43 "command\0" Required_argument "c"
44 "flush\0" No_argument "f"
45 "quiet\0" No_argument "q"
48 applet_long_options = getopt_longopts;
50 opt_complementary = "?1"; /* max one arg */
51 opt = getopt32(argv, "ac:fq", &shell_arg);
57 mode = O_CREAT|O_TRUNC|O_WRONLY;
59 mode = O_CREAT|O_APPEND|O_WRONLY;
64 if (!(opt & 8)) { /* not -q */
65 printf("Script started, file is %s\n", fname);
67 shell = getenv("SHELL");
69 shell = DEFAULT_SHELL;
72 pty = xgetpty(pty_line);
74 /* get current stdin's tty params */
75 attr_ok = tcgetattr(0, &tt);
76 winsz_ok = ioctl(0, TIOCGWINSZ, (char *)&win);
81 tcsetattr(0, TCSAFLUSH, &rtt);
83 /* "script" from util-linux exits when child exits,
84 * we wouldn't wait for EOF from slave pty
85 * (output may be produced by grandchildren of child) */
86 signal(SIGCHLD, handle_sigchld);
88 /* TODO: SIGWINCH? pass window size changes down to slave? */
92 bb_perror_msg_and_die("vfork");
97 #define buf bb_common_bufsiz1
99 int outfd, count, loop;
101 outfd = xopen(fname, mode);
103 pfd[0].events = POLLIN;
105 pfd[1].events = POLLIN;
106 ndelay_on(pty); /* this descriptor is not shared, can do this */
107 /* ndelay_on(0); - NO, stdin can be shared! Pity :( */
109 /* copy stdin to pty master input,
110 * copy pty master output to stdout and file */
111 /* TODO: don't use full_write's, use proper write buffering */
113 /* not safe_poll! we want SIGCHLD to EINTR poll */
114 if (poll(pfd, fd_count, -1) < 0 && errno != EINTR) {
115 /* If child exits too quickly, we may get EIO:
116 * for example, try "script -c true" */
119 if (pfd[0].revents) {
121 count = safe_read(pty, buf, sizeof(buf));
122 if (count <= 0 && errno != EAGAIN) {
123 /* err/eof from pty: exit */
127 full_write(STDOUT_FILENO, buf, count);
128 full_write(outfd, buf, count);
129 if (opt & 4) { /* -f */
134 if (pfd[1].revents) {
135 count = safe_read(STDIN_FILENO, buf, sizeof(buf));
137 /* err/eof from stdin: don't read stdin anymore */
141 full_write(pty, buf, count);
145 /* If loop was exited because SIGCHLD handler set fd_count to 0,
146 * there still can be some buffered output. But not loop forever:
147 * we won't pump orphaned grandchildren's output indefinitely.
148 * Testcase: running this in script:
149 * exec dd if=/dev/zero bs=1M count=1
150 * must have "1+0 records in, 1+0 records out" captured too.
151 * (util-linux's script doesn't do this. buggy :) */
153 /* pty is in O_NONBLOCK mode, we exit as soon as buffer is empty */
154 while (--loop && (count = safe_read(pty, buf, sizeof(buf))) > 0) {
155 full_write(STDOUT_FILENO, buf, count);
156 full_write(outfd, buf, count);
160 tcsetattr(0, TCSAFLUSH, &tt);
161 if (!(opt & 8)) /* not -q */
162 printf("Script done, file is %s\n", fname);
166 /* child: make pty slave to be input, output, error; run shell */
167 close(pty); /* close pty master */
168 /* open pty slave to fd 0,1,2 */
170 xopen(pty_line, O_RDWR); /* uses fd 0 */
173 /* copy our original stdin tty's parameters to pty */
175 tcsetattr(0, TCSAFLUSH, &tt);
177 ioctl(0, TIOCSWINSZ, (char *)&win);
178 /* set pty as a controlling tty */
180 ioctl(0, TIOCSCTTY, 0 /* 0: don't forcibly steal */);
182 /* Non-ignored signals revert to SIG_DFL on exec anyway */
183 /*signal(SIGCHLD, SIG_DFL);*/
184 execl(shell, shell, shell_opt, shell_arg, NULL);
185 bb_simple_perror_msg_and_die(shell);