source: MondoRescue/branches/2.2.0/mindi-busybox/coreutils/tee.c@ 3776

/* vi: set sw=4 ts=4: */
/*
 * tee implementation for busybox
 *
 * Copyright (C) 2003  Manuel Novoa III  <mjn3@codepoet.org>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
 * General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 *
 */

/* BB_AUDIT SUSv3 compliant */
/* http://www.opengroup.org/onlinepubs/007904975/utilities/tee.html */

#include <stdio.h>
#include <stdlib.h>
#include <signal.h>
#include <unistd.h>
#include "busybox.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 = bb_getopt_ulflags(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 = bb_wfopen(*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 bb_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! */
        bb_xferror(*p, filenames[(int)(p - files)]);
    } while (*++p);

    bb_fflush_stdout_and_exit(retval);
}