1 /* vi: set sw=4 ts=4: */
2 /*
3 * tee implementation for busybox
4 *
5 * Copyright (C) 2003 Manuel Novoa III <mjn3@codepoet.org>
6 *
7 * Licensed under GPLv2 or later, see file LICENSE in this source tree.
8 */
9 //config:config TEE
10 //config: bool "tee (4.2 kb)"
11 //config: default y
12 //config: help
13 //config: tee is used to read from standard input and write
14 //config: to standard output and files.
15 //config:
16 //config:config FEATURE_TEE_USE_BLOCK_IO
17 //config: bool "Enable block I/O (larger/faster) instead of byte I/O"
18 //config: default y
19 //config: depends on TEE
20 //config: help
21 //config: Enable this option for a faster tee, at expense of size.
22
23 //applet:IF_TEE(APPLET(tee, BB_DIR_USR_BIN, BB_SUID_DROP))
24
25 //kbuild:lib-$(CONFIG_TEE) += tee.o
26
27 /* BB_AUDIT SUSv3 compliant */
28 /* http://www.opengroup.org/onlinepubs/007904975/utilities/tee.html */
29
30 //usage:#define tee_trivial_usage
31 //usage: "[-ai] [FILE]..."
32 //usage:#define tee_full_usage "\n\n"
33 //usage: "Copy stdin to each FILE, and also to stdout\n"
34 //usage: "\n -a Append to the given FILEs, don't overwrite"
35 //usage: "\n -i Ignore interrupt signals (SIGINT)"
36 //usage:
37 //usage:#define tee_example_usage
38 //usage: "$ echo \"Hello\" | tee /tmp/foo\n"
39 //usage: "$ cat /tmp/foo\n"
40 //usage: "Hello\n"
41
42 // Bare "tee" with no below options does not install SIGPIPE handler - just dies on it.
43 // TODO:
44 // --output-error[=MODE]
45 // 'warn' diagnose errors writing to any output
46 // 'warn-nopipe' diagnose errors writing to any output not a pipe
47 // 'exit' exit on error writing to any output
48 // 'exit-nopipe' exit on error writing to any output not a pipe
49 // ^^^ all of these should set SIGPIPE to SIG_IGN.
50 // Because "exit" mode should print error message and exit1(1) - not die on SIGPIPE.
51 // "exit-nopipe" does not exit on EPIPE and does not set exitcode to 1 too.
52 // -p diagnose errors writing to non pipes
53 // ^^^^ this should set SIGPIPE to SIG_IGN. EPIPE is ignored (same as "warn-nopipe")
54
55 #include "libbb.h"
56 #include "common_bufsiz.h"
57
58 int tee_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
tee_main(int argc,char ** argv)59 int tee_main(int argc, char **argv)
60 {
61 const char *mode = "w\0a";
62 FILE **files;
63 FILE **fp;
64 char **names;
65 char **np;
66 char retval;
67 //TODO: make unconditional
68 #if ENABLE_FEATURE_TEE_USE_BLOCK_IO
69 ssize_t c;
70 # define buf bb_common_bufsiz1
71 setup_common_bufsiz();
72 #else
73 int c;
74 #endif
75 retval = getopt32(argv, "ia"); /* 'a' must be 2nd */
76 argc -= optind;
77 argv += optind;
78
79 mode += (retval & 2); /* Since 'a' is the 2nd option... */
80
81 if (retval & 1) {
82 signal(SIGINT, SIG_IGN);
83 }
84 retval = EXIT_SUCCESS;
85 /* if (opt_p || opt_output_error)
86 signal(SIGPIPE, SIG_IGN);
87 */
88
89 /* Allocate an array of FILE *'s, with one extra for a sentinel. */
90 fp = files = xzalloc(sizeof(FILE *) * (argc + 2));
91 np = names = argv - 1;
92
93 files[0] = stdout;
94 goto GOT_NEW_FILE;
95
96 do {
97 *fp = stdout;
98 if (NOT_LONE_DASH(*argv)) {
99 *fp = fopen_or_warn(*argv, mode);
100 if (*fp == NULL) {
101 retval = EXIT_FAILURE;
102 argv++;
103 continue;
104 }
105 }
106 *np = *argv++;
107 GOT_NEW_FILE:
108 setbuf(*fp, NULL); /* tee must not buffer output. */
109 fp++;
110 np++;
111 } while (*argv);
112 /* names[0] will be filled later */
113
114 #if ENABLE_FEATURE_TEE_USE_BLOCK_IO
115 while ((c = safe_read(STDIN_FILENO, buf, COMMON_BUFSIZE)) > 0) {
116 fp = files;
117 do
118 fwrite(buf, 1, c, *fp);
119 /* if (opt_p && fwrite() != c && !EPIPE) bb_error_msg("..."); */
120 while (*++fp);
121 }
122 if (c < 0) { /* Make sure read errors are signaled. */
123 retval = EXIT_FAILURE;
124 }
125 #else
126 setvbuf(stdout, NULL, _IONBF, 0);
127 while ((c = getchar()) != EOF) {
128 fp = files;
129 do
130 putc(c, *fp);
131 /* if (opt_p && putc() == EOF && !EPIPE) bb_error_msg("..."); */
132 while (*++fp);
133 }
134 #endif
135
136 /* Now we need to check for i/o errors on stdin and the various
137 * output files. Since we know that the first entry in the output
138 * file table is stdout, we can save one "if ferror" test by
139 * setting the first entry to stdin and checking stdout error
140 * status with fflush_stdout_and_exit()... although fflush()ing
141 * is unnecessary here. */
142 np = names;
143 fp = files;
144 names[0] = (char *) bb_msg_standard_input;
145 files[0] = stdin;
146 do { /* Now check for input and output errors. */
147 /* Checking ferror should be sufficient, but we may want to fclose.
148 * If we do, remember not to close stdin! */
149 die_if_ferror(*fp++, *np++);
150 } while (*fp);
151
152 fflush_stdout_and_exit(retval);
153 }
154