busybox/coreutils/tee.c

103 lines
2.6 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 tarball for details.
*/
/* BB_AUDIT SUSv3 compliant */
/* http://www.opengroup.org/onlinepubs/007904975/utilities/tee.html */
#include "libbb.h"
#include <signal.h>
int tee_main(int argc, char **argv);
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
#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); /* TODO - switch to sigaction. */
}
retval = EXIT_SUCCESS;
/* gnu tee ignores SIGPIPE in case one of the output files is a pipe
* that doesn't consume all its input. Good idea... */
signal(SIGPIPE, SIG_IGN); /* TODO - switch to sigaction. */
/* Allocate an array of FILE *'s, with one extra for a sentinal. */
fp = files = xzalloc(sizeof(FILE *) * (argc + 2));
np = names = argv - 1;
files[0] = stdout;
goto GOT_NEW_FILE;
do {
*fp = fopen_or_warn(*argv, mode);
if (*fp == NULL) {
retval = EXIT_FAILURE;
continue;
}
*np = *argv++;
GOT_NEW_FILE:
setbuf(*fp++, NULL); /* tee must not buffer output. */
np++;
} while (*argv);
/* names[0] will be filled later */
#if ENABLE_FEATURE_TEE_USE_BLOCK_IO
while ((c = safe_read(STDIN_FILENO, buf, sizeof(buf))) > 0) {
fp = files;
do
fwrite(buf, 1, c, *fp++);
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++);
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);
}