busybox/coreutils/tee.c
Denys Vlasenko 427c12cc51 tee: do not intercept SIGPIPE
GNU tee does this only with -p, which we don't have yet.

function                                             old     new   delta
tee_main                                             306     295     -11

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2019-10-07 14:25:45 +02:00

154 lines
4.3 KiB
C

/* vi: set sw=4 ts=4: */
/*
* tee implementation for busybox
*
* Copyright (C) 2003 Manuel Novoa III <mjn3@codepoet.org>
*
* Licensed under GPLv2 or later, see file LICENSE in this source tree.
*/
//config:config TEE
//config: bool "tee (4.2 kb)"
//config: default y
//config: help
//config: tee is used to read from standard input and write
//config: to standard output and files.
//config:
//config:config FEATURE_TEE_USE_BLOCK_IO
//config: bool "Enable block I/O (larger/faster) instead of byte I/O"
//config: default y
//config: depends on TEE
//config: help
//config: Enable this option for a faster tee, at expense of size.
//applet:IF_TEE(APPLET(tee, BB_DIR_USR_BIN, BB_SUID_DROP))
//kbuild:lib-$(CONFIG_TEE) += tee.o
/* BB_AUDIT SUSv3 compliant */
/* http://www.opengroup.org/onlinepubs/007904975/utilities/tee.html */
//usage:#define tee_trivial_usage
//usage: "[-ai] [FILE]..."
//usage:#define tee_full_usage "\n\n"
//usage: "Copy stdin to each FILE, and also to stdout\n"
//usage: "\n -a Append to the given FILEs, don't overwrite"
//usage: "\n -i Ignore interrupt signals (SIGINT)"
//usage:
//usage:#define tee_example_usage
//usage: "$ echo \"Hello\" | tee /tmp/foo\n"
//usage: "$ cat /tmp/foo\n"
//usage: "Hello\n"
// Bare "tee" with no below options does not install SIGPIPE handler - just dies on it.
// TODO:
// --output-error[=MODE]
// 'warn' diagnose errors writing to any output
// 'warn-nopipe' diagnose errors writing to any output not a pipe
// 'exit' exit on error writing to any output
// 'exit-nopipe' exit on error writing to any output not a pipe
// ^^^ all of these should set SIGPIPE to SIG_IGN.
// Because "exit" mode should print error message and exit1(1) - not die on SIGPIPE.
// "exit-nopipe" does not exit on EPIPE and does not set exitcode to 1 too.
// -p diagnose errors writing to non pipes
// ^^^^ this should set SIGPIPE to SIG_IGN. EPIPE is ignored (same as "warn-nopipe")
#include "libbb.h"
#include "common_bufsiz.h"
int tee_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
int tee_main(int argc, char **argv)
{
const char *mode = "w\0a";
FILE **files;
FILE **fp;
char **names;
char **np;
char retval;
//TODO: make unconditional
#if ENABLE_FEATURE_TEE_USE_BLOCK_IO
ssize_t c;
# define buf bb_common_bufsiz1
setup_common_bufsiz();
#else
int c;
#endif
retval = getopt32(argv, "ia"); /* 'a' must be 2nd */
argc -= optind;
argv += optind;
mode += (retval & 2); /* Since 'a' is the 2nd option... */
if (retval & 1) {
signal(SIGINT, SIG_IGN);
}
retval = EXIT_SUCCESS;
/* if (opt_p || opt_output_error)
signal(SIGPIPE, SIG_IGN);
*/
/* Allocate an array of FILE *'s, with one extra for a sentinel. */
fp = files = xzalloc(sizeof(FILE *) * (argc + 2));
np = names = argv - 1;
files[0] = stdout;
goto GOT_NEW_FILE;
do {
*fp = stdout;
if (NOT_LONE_DASH(*argv)) {
*fp = fopen_or_warn(*argv, mode);
if (*fp == NULL) {
retval = EXIT_FAILURE;
argv++;
continue;
}
}
*np = *argv++;
GOT_NEW_FILE:
setbuf(*fp, NULL); /* tee must not buffer output. */
fp++;
np++;
} while (*argv);
/* names[0] will be filled later */
#if ENABLE_FEATURE_TEE_USE_BLOCK_IO
while ((c = safe_read(STDIN_FILENO, buf, COMMON_BUFSIZE)) > 0) {
fp = files;
do
fwrite(buf, 1, c, *fp);
/* if (opt_p && fwrite() != c && !EPIPE) bb_error_msg("..."); */
while (*++fp);
}
if (c < 0) { /* Make sure read errors are signaled. */
retval = EXIT_FAILURE;
}
#else
setvbuf(stdout, NULL, _IONBF, 0);
while ((c = getchar()) != EOF) {
fp = files;
do
putc(c, *fp);
/* if (opt_p && putc() == EOF && !EPIPE) bb_error_msg("..."); */
while (*++fp);
}
#endif
/* Now we need to check for i/o errors on stdin and the various
* output files. Since we know that the first entry in the output
* file table is stdout, we can save one "if ferror" test by
* setting the first entry to stdin and checking stdout error
* status with fflush_stdout_and_exit()... although fflush()ing
* is unnecessary here. */
np = names;
fp = files;
names[0] = (char *) bb_msg_standard_input;
files[0] = stdin;
do { /* Now check for input and output errors. */
/* Checking ferror should be sufficient, but we may want to fclose.
* If we do, remember not to close stdin! */
die_if_ferror(*fp++, *np++);
} while (*fp);
fflush_stdout_and_exit(retval);
}