lib/libc/stdio/perror.c

   1 /*
   2  * Copyright (c) 1988, 1993
   3  *      The Regents of the University of California.  All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions
   7  * are met:
   8  * 1. Redistributions of source code must retain the above copyright
   9  *    notice, this list of conditions and the following disclaimer.
  10  * 2. Redistributions in binary form must reproduce the above copyright
  11  *    notice, this list of conditions and the following disclaimer in the
  12  *    documentation and/or other materials provided with the distribution.
  13  * 3. All advertising materials mentioning features or use of this software
  14  *    must display the following acknowledgement:
  15  *      This product includes software developed by the University of
  16  *      California, Berkeley and its contributors.
  17  * 4. Neither the name of the University nor the names of its contributors
  18  *    may be used to endorse or promote products derived from this software
  19  *    without specific prior written permission.
  20  *
  21  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  31  * SUCH DAMAGE.
  32  *
  33  * $FreeBSD: src/lib/libc/stdio/perror.c,v 1.3.6.1 2001/03/05 11:27:49 obrien Exp $
  34  * $DragonFly: src/lib/libc/stdio/perror.c,v 1.7 2005/11/20 11:07:30 swildner Exp $
  35  *
  36  * @(#)perror.c 8.1 (Berkeley) 6/4/93
  37  */
  38
  39 #include "namespace.h"
  40 #include <sys/types.h>
  41 #include <sys/uio.h>
  42 #include <unistd.h>
  43 #include <errno.h>
  44 #include <stdio.h>
  45 #include <string.h>
  46 #include "un-namespace.h"
  47
  48 void
  49 perror(const char *s)
  50 {
  51         struct iovec *v;
  52         struct iovec iov[4];
  53
  54         v = iov;
  55         if (s != NULL && *s != '\0') {
  56                 v->iov_base = __DECONST(char *, s);
  57                 v->iov_len = strlen(s);
  58                 v++;
  59                 v->iov_base = __DECONST(char *, ": ");
  60                 v->iov_len = 2;
  61                 v++;
  62         }
  63         v->iov_base = strerror(errno);
  64         v->iov_len = strlen(v->iov_base);
  65         v++;
  66         v->iov_base = __DECONST(char *, "\n");
  67         v->iov_len = 1;
  68         _writev(STDERR_FILENO, iov, (v - iov) + 1);
  69 }