external/bsd/dhcpcd/dist/compat/getline.c

   1 /*
   2  * dhcpcd - DHCP client daemon
   3  * Copyright (c) 2006-2009 Roy Marples <roy@marples.name>
   4  * All rights reserved
   5
   6  * Redistribution and use in source and binary forms, with or without
   7  * modification, are permitted provided that the following conditions
   8  * are met:
   9  * 1. Redistributions of source code must retain the above copyright
  10  *    notice, this list of conditions and the following disclaimer.
  11  * 2. Redistributions in binary form must reproduce the above copyright
  12  *    notice, this list of conditions and the following disclaimer in the
  13  *    documentation and/or other materials provided with the distribution.
  14  *
  15  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
  16  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  17  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  18  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
  19  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  20  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  21  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  22  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  23  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  24  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  25  * SUCH DAMAGE.
  26  */
  27
  28 #include <errno.h>
  29 #include <stdint.h>
  30 #include <stdlib.h>
  31 #include <stdio.h>
  32 #include <string.h>
  33
  34 #include "getline.h"
  35
  36 /* Redefine a small buffer for our simple text config files */
  37 #undef BUFSIZ
  38 #define BUFSIZ 128
  39
  40 ssize_t
  41 getline(char ** __restrict buf, size_t * __restrict buflen,
  42     FILE * __restrict fp)
  43 {
  44         size_t bytes, newlen;
  45         char *newbuf, *p;
  46
  47         if (buf == NULL || buflen == NULL) {
  48                 errno = EINVAL;
  49                 return -1;
  50         }
  51         if (*buf == NULL)
  52                 *buflen = 0;
  53
  54         bytes = 0;
  55         do {
  56                 if (feof(fp))
  57                         break;
  58                 if (*buf == NULL || bytes != 0) {
  59                         newlen = *buflen + BUFSIZ;
  60                         newbuf = realloc(*buf, newlen);
  61                         if (newbuf == NULL)
  62                                 return -1;
  63                         *buf = newbuf;
  64                         *buflen = newlen;
  65                 }
  66                 p = *buf + bytes;
  67                 memset(p, 0, BUFSIZ);
  68                 if (fgets(p, BUFSIZ, fp) == NULL)
  69                         break;
  70                 bytes += strlen(p);
  71         } while (bytes == 0 || *(*buf + (bytes - 1)) != '\n');
  72         if (bytes == 0)
  73                 return -1;
  74         return bytes;
  75 }