/* pidfile.c - process id file functions
 * Time-stamp: <2010-11-03 05:19:23 nk>
 *
 * (c) 2003-2010 Nicholas J. Kain <njkain at gmail dot com>
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *
 * - Redistributions of source code must retain the above copyright notice,
 *   this list of conditions and the following disclaimer.
 *
 * - Redistributions in binary form must reproduce the above copyright notice,
 *   this list of conditions and the following disclaimer in the documentation
 *   and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 */

#include <stdio.h>
#include <stdlib.h>
#include <sys/types.h>
#include <unistd.h>
#include <string.h>

#include "defines.h"
#include "log.h"

void write_pid(const char *file) {
    FILE *f;
    size_t written, len;
    char buf[MAXLINE];

    f = fopen(file, "w");
    if (f == NULL) {
        log_line("FATAL - failed to open pid file \"%s\"!\n", file);
        exit(EXIT_FAILURE);
    }

    snprintf(buf, sizeof buf - 1, "%i", (unsigned int)getpid());
    len = strlen(buf);
    written = 0;
    while (written < len)
        written = fwrite(buf + written, sizeof (char), len - written, f);

    if (fclose(f) != 0) {
        log_line("FATAL - failed to close pid file \"%s\"!\n", file);
        exit(EXIT_FAILURE);
    }
}

/* Return 0 on success, -1 on failure. */
int file_exists(const char *file, const char *mode) {
    FILE *f;

    if (file == NULL || mode == NULL) {
        log_line("file_exists: FATAL - coding bug: NULL passed\n");
        return -1;
    }

    f = fopen(file, mode);
    if (f == NULL) {
        log_line("file_exists: FATAL - can't open file %s with mode %s!\n",
                 file, mode);
        return -1;
    }
    fclose(f);
    return 0;
}