hush/coreutils/tee.c
2006-10-26 23:25:17 +00:00

101 lines
2.5 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 "busybox.h"
#include <signal.h>
int tee_main(int argc, char **argv)
{
const char *mode = "w\0a";
FILE **files;
FILE **p;
char **filenames;
int flags;
int retval = EXIT_SUCCESS;
#ifdef CONFIG_FEATURE_TEE_USE_BLOCK_IO
ssize_t c;
# define buf bb_common_bufsiz1
#else
int c;
#endif
flags = getopt32(argc, argv, "ia"); /* 'a' must be 2nd */
mode += (flags & 2); /* Since 'a' is the 2nd option... */
if (flags & 1) {
signal(SIGINT, SIG_IGN); /* TODO - switch to sigaction.*/
}
/* 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. */
p = files = (FILE **)xmalloc(sizeof(FILE *) * (argc - optind + 2));
*p = stdout;
argv += optind - 1;
filenames = argv - 1;
*filenames = (char *) bb_msg_standard_input; /* for later */
goto GOT_NEW_FILE;
do {
if ((*p = fopen_or_warn(*argv, mode)) == NULL) {
retval = EXIT_FAILURE;
continue;
}
filenames[(int)(p - files)] = *argv;
GOT_NEW_FILE:
setbuf(*p, NULL); /* tee must not buffer output. */
++p;
} while (*++argv);
*p = NULL; /* Store the sentinal value. */
#ifdef CONFIG_FEATURE_TEE_USE_BLOCK_IO
while ((c = safe_read(STDIN_FILENO, buf, BUFSIZ)) > 0) {
for (p=files ; *p ; p++) {
fwrite(buf, 1, c, *p);
}
}
if (c < 0) { /* Make sure read errors are signaled. */
retval = EXIT_FAILURE;
}
#else
setvbuf(stdout, NULL, _IONBF, 0);
while ((c = getchar()) != EOF) {
for (p=files ; *p ; p++) {
putc(c, *p);
}
}
#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. */
p = files;
*p = 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(*p, filenames[(int)(p - files)]);
} while (*++p);
fflush_stdout_and_exit(retval);
}