Contents of /tags/mkinitrd-6_1_4/busybox/util-linux/script.c
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Wed Aug 5 16:25:39 2009 UTC (15 years, 1 month ago) by niro
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File size: 4956 byte(s)
Wed Aug 5 16:25:39 2009 UTC (15 years, 1 month ago) by niro
File MIME type: text/plain
File size: 4956 byte(s)
tagged 'mkinitrd-6_1_4'
1 | /* vi: set sw=4 ts=4: */ |
2 | /* |
3 | * script implementation for busybox |
4 | * |
5 | * pascal.bellard@ads-lu.com |
6 | * |
7 | * Based on code from util-linux v 2.12r |
8 | * Copyright (c) 1980 |
9 | * The Regents of the University of California. All rights reserved. |
10 | * |
11 | * Licensed under GPLv2 or later, see file License in this tarball for details. |
12 | */ |
13 | |
14 | #include "libbb.h" |
15 | |
16 | static smallint fd_count = 2; |
17 | |
18 | static void handle_sigchld(int sig UNUSED_PARAM) |
19 | { |
20 | fd_count = 0; |
21 | } |
22 | |
23 | int script_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE; |
24 | int script_main(int argc UNUSED_PARAM, char **argv) |
25 | { |
26 | int opt; |
27 | int mode; |
28 | int child_pid; |
29 | int attr_ok; /* NB: 0: ok */ |
30 | int winsz_ok; |
31 | int pty; |
32 | char pty_line[GETPTY_BUFSIZE]; |
33 | struct termios tt, rtt; |
34 | struct winsize win; |
35 | const char *fname = "typescript"; |
36 | const char *shell; |
37 | char shell_opt[] = "-i"; |
38 | char *shell_arg = NULL; |
39 | |
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" |
46 | ; |
47 | |
48 | applet_long_options = getopt_longopts; |
49 | #endif |
50 | opt_complementary = "?1"; /* max one arg */ |
51 | opt = getopt32(argv, "ac:fq", &shell_arg); |
52 | //argc -= optind; |
53 | argv += optind; |
54 | if (argv[0]) { |
55 | fname = argv[0]; |
56 | } |
57 | mode = O_CREAT|O_TRUNC|O_WRONLY; |
58 | if (opt & 1) { |
59 | mode = O_CREAT|O_APPEND|O_WRONLY; |
60 | } |
61 | if (opt & 2) { |
62 | shell_opt[1] = 'c'; |
63 | } |
64 | if (!(opt & 8)) { /* not -q */ |
65 | printf("Script started, file is %s\n", fname); |
66 | } |
67 | shell = getenv("SHELL"); |
68 | if (shell == NULL) { |
69 | shell = DEFAULT_SHELL; |
70 | } |
71 | |
72 | pty = xgetpty(pty_line); |
73 | |
74 | /* get current stdin's tty params */ |
75 | attr_ok = tcgetattr(0, &tt); |
76 | winsz_ok = ioctl(0, TIOCGWINSZ, (char *)&win); |
77 | |
78 | rtt = tt; |
79 | cfmakeraw(&rtt); |
80 | rtt.c_lflag &= ~ECHO; |
81 | tcsetattr(0, TCSAFLUSH, &rtt); |
82 | |
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); |
87 | |
88 | /* TODO: SIGWINCH? pass window size changes down to slave? */ |
89 | |
90 | child_pid = vfork(); |
91 | if (child_pid < 0) { |
92 | bb_perror_msg_and_die("vfork"); |
93 | } |
94 | |
95 | if (child_pid) { |
96 | /* parent */ |
97 | #define buf bb_common_bufsiz1 |
98 | struct pollfd pfd[2]; |
99 | int outfd, count, loop; |
100 | |
101 | outfd = xopen(fname, mode); |
102 | pfd[0].fd = pty; |
103 | pfd[0].events = POLLIN; |
104 | pfd[1].fd = 0; |
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 :( */ |
108 | |
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 */ |
112 | while (fd_count) { |
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" */ |
117 | break; |
118 | } |
119 | if (pfd[0].revents) { |
120 | errno = 0; |
121 | count = safe_read(pty, buf, sizeof(buf)); |
122 | if (count <= 0 && errno != EAGAIN) { |
123 | /* err/eof from pty: exit */ |
124 | goto restore; |
125 | } |
126 | if (count > 0) { |
127 | full_write(STDOUT_FILENO, buf, count); |
128 | full_write(outfd, buf, count); |
129 | if (opt & 4) { /* -f */ |
130 | fsync(outfd); |
131 | } |
132 | } |
133 | } |
134 | if (pfd[1].revents) { |
135 | count = safe_read(STDIN_FILENO, buf, sizeof(buf)); |
136 | if (count <= 0) { |
137 | /* err/eof from stdin: don't read stdin anymore */ |
138 | pfd[1].revents = 0; |
139 | fd_count--; |
140 | } else { |
141 | full_write(pty, buf, count); |
142 | } |
143 | } |
144 | } |
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 :) */ |
152 | loop = 999; |
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); |
157 | } |
158 | restore: |
159 | if (attr_ok == 0) |
160 | tcsetattr(0, TCSAFLUSH, &tt); |
161 | if (!(opt & 8)) /* not -q */ |
162 | printf("Script done, file is %s\n", fname); |
163 | return EXIT_SUCCESS; |
164 | } |
165 | |
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 */ |
169 | close(0); |
170 | xopen(pty_line, O_RDWR); /* uses fd 0 */ |
171 | xdup2(0, 1); |
172 | xdup2(0, 2); |
173 | /* copy our original stdin tty's parameters to pty */ |
174 | if (attr_ok == 0) |
175 | tcsetattr(0, TCSAFLUSH, &tt); |
176 | if (winsz_ok == 0) |
177 | ioctl(0, TIOCSWINSZ, (char *)&win); |
178 | /* set pty as a controlling tty */ |
179 | setsid(); |
180 | ioctl(0, TIOCSCTTY, 0 /* 0: don't forcibly steal */); |
181 | |
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); |
186 | } |