1 /* vi: set sw=4 ts=4: */
3 * tee implementation for busybox
5 * Copyright (C) 2003 Manuel Novoa III <mjn3@codepoet.org>
7 * Licensed under GPLv2 or later, see file LICENSE in this source tree.
10 /* BB_AUDIT SUSv3 compliant */
11 /* http://www.opengroup.org/onlinepubs/007904975/utilities/tee.html */
13 //usage:#define tee_trivial_usage
14 //usage: "[-ai] [FILE]..."
15 //usage:#define tee_full_usage "\n\n"
16 //usage: "Copy stdin to each FILE, and also to stdout\n"
17 //usage: "\n -a Append to the given FILEs, don't overwrite"
18 //usage: "\n -i Ignore interrupt signals (SIGINT)"
20 //usage:#define tee_example_usage
21 //usage: "$ echo \"Hello\" | tee /tmp/foo\n"
22 //usage: "$ cat /tmp/foo\n"
27 int tee_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
28 int tee_main(int argc, char **argv)
30 const char *mode = "w\0a";
36 //TODO: make unconditional
37 #if ENABLE_FEATURE_TEE_USE_BLOCK_IO
39 # define buf bb_common_bufsiz1
43 retval = getopt32(argv, "ia"); /* 'a' must be 2nd */
47 mode += (retval & 2); /* Since 'a' is the 2nd option... */
50 signal(SIGINT, SIG_IGN); /* TODO - switch to sigaction. (why?) */
52 retval = EXIT_SUCCESS;
53 /* gnu tee ignores SIGPIPE in case one of the output files is a pipe
54 * that doesn't consume all its input. Good idea... */
55 signal(SIGPIPE, SIG_IGN);
57 /* Allocate an array of FILE *'s, with one extra for a sentinel. */
58 fp = files = xzalloc(sizeof(FILE *) * (argc + 2));
59 np = names = argv - 1;
65 if (NOT_LONE_DASH(*argv)) {
66 *fp = fopen_or_warn(*argv, mode);
68 retval = EXIT_FAILURE;
75 setbuf(*fp, NULL); /* tee must not buffer output. */
79 /* names[0] will be filled later */
81 #if ENABLE_FEATURE_TEE_USE_BLOCK_IO
82 while ((c = safe_read(STDIN_FILENO, buf, sizeof(buf))) > 0) {
85 fwrite(buf, 1, c, *fp);
88 if (c < 0) { /* Make sure read errors are signaled. */
89 retval = EXIT_FAILURE;
92 setvbuf(stdout, NULL, _IONBF, 0);
93 while ((c = getchar()) != EOF) {
101 /* Now we need to check for i/o errors on stdin and the various
102 * output files. Since we know that the first entry in the output
103 * file table is stdout, we can save one "if ferror" test by
104 * setting the first entry to stdin and checking stdout error
105 * status with fflush_stdout_and_exit()... although fflush()ing
106 * is unnecessary here. */
109 names[0] = (char *) bb_msg_standard_input;
111 do { /* Now check for input and output errors. */
112 /* Checking ferror should be sufficient, but we may want to fclose.
113 * If we do, remember not to close stdin! */
114 die_if_ferror(*fp++, *np++);
117 fflush_stdout_and_exit(retval);