error.c

/*
 * The TCP Scanner (tcp-scan) is Copyright (C) 2003-2008 Roy Hills,
 * NTA Monitor Ltd.
 *
 * This file is part of tcp-scan.
 *
 * tcp-scan 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 3 of the License, or
 * (at your option) any later version.
 *
 * tcp-scan 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 tcp-scan.  If not, see <http://www.gnu.org/licenses/>.
 *
 * error.c -- error routines for tcp-scan
 *
 * Author:	Roy Hills
 * Date:	1 December 2001
 */

#include "tcp-scan.h"

int daemon_proc;	/* Non-zero if process is a daemon */

/*
 *	Function to handle fatal system call errors.
 */
void
err_sys(const char *fmt,...) {
   va_list ap;

   va_start(ap, fmt);
   err_print(1, fmt, ap);
   va_end(ap);
   exit(EXIT_FAILURE);
}

/*
 *	Function to handle non-fatal system call errors.
 */
void
warn_sys(const char *fmt,...) {
   va_list ap;

   va_start(ap, fmt);
   err_print(1, fmt, ap);
   va_end(ap);
}

/*
 *	Function to handle fatal errors not from system calls.
 */
void
err_msg(const char *fmt,...) {
   va_list ap;

   va_start(ap, fmt);
   err_print(0, fmt, ap);
   va_end(ap);
   exit(EXIT_FAILURE);
}

/*
 *	Function to handle non-fatal errors not from system calls.
 */
void
warn_msg(const char *fmt,...) {
   va_list ap;

   va_start(ap, fmt);
   err_print(0, fmt, ap);
   va_end(ap);
}

/*
 *	General error printing function used by all the above
 *	functions.
 */
void
err_print (int errnoflag, const char *fmt, va_list ap) {
   int errno_save;
   size_t n;
   char buf[MAXLINE];

   errno_save=errno;

   vsnprintf(buf, MAXLINE, fmt, ap);
   n=strlen(buf);
   if (errnoflag)
     snprintf(buf+n, MAXLINE-n, ": %s", strerror(errno_save));
   strlcat(buf, "\n", sizeof(buf));

   fflush(stdout);	/* In case stdout and stderr are the same */
   fputs(buf, stderr);
   fflush(stderr);
}