/********************************************************
 * log_msg -- Write a message to the log file.          *
 ********************************************************/
#include <stdio.h>
#include <sys/fcntl.h>
#include <stdarg.h>
#include <unistd.h>
#include <string.h>
#include "log_msg.h"

/********************************************************
 * log_msg -- Write a message to the log file.          *
 *      Uses printf type arguements.                    *
 ********************************************************/
void log_msg(char *fmt, ...)
{
    char full_string[5000];     /* The string containing the message */
    va_list ap;                 /* For variable arguements */
    static int log_fd = -1;     /* FD of the file to write */

    if (log_fd < 0) {
        char log_file_name[100];        /* Name of the log file */

        sprintf(log_file_name, "debug_log.%d", getpid());

        log_fd = open(log_file_name, O_WRONLY|O_CREAT, 0666);
    }
    va_start(ap, fmt);
    vsnprintf(full_string, sizeof(full_string), fmt, ap);
    if (log_fd >= 0) {
        write(log_fd, full_string, strlen(full_string));
    }
}