compat_getline.c

   1 /* $Id: compat_getline.c,v 1.2 2020/06/15 01:37:14 schwarze Exp $ */
   2 /*
   3  * Copyright (c) 2015 Ingo Schwarze <schwarze@openbsd.org>
   4  *
   5  * Permission to use, copy, modify, and distribute this software for any
   6  * purpose with or without fee is hereby granted, provided that the above
   7  * copyright notice and this permission notice appear in all copies.
   8  *
   9  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
  10  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
  11  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
  12  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
  13  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
  14  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
  15  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  16  */
  17 #include "config.h"
  18
  19 #include <sys/types.h>
  20 #include <errno.h>
  21 #include <stdio.h>
  22 #include <stdlib.h>
  23
  24 ssize_t
  25 getline(char **buf, size_t *bufsz, FILE *fp)
  26 {
  27         char    *nbuf;
  28         size_t   nbufsz, pos;
  29         int      c;
  30
  31         if (buf == NULL || bufsz == NULL) {
  32                 errno = EINVAL;
  33                 return -1;
  34         }
  35
  36         if (*buf == NULL)
  37                 *bufsz = 0;
  38         else
  39                 **buf = '\0';
  40
  41         pos = 0;
  42         for (;;) {
  43                 if (pos + 1 >= *bufsz) {
  44                         nbufsz = *bufsz ? *bufsz * 2 : BUFSIZ;
  45                         if ((nbuf = realloc(*buf, nbufsz)) == NULL)
  46                                 return -1;
  47                         *buf = nbuf;
  48                         *bufsz = nbufsz;
  49                 }
  50                 if ((c = fgetc(fp)) == EOF) {
  51                         (*buf)[pos] = '\0';
  52                         return pos > 0 && feof(fp) ? (ssize_t)pos : -1;
  53                 }
  54                 (*buf)[pos++] = c;
  55                 (*buf)[pos] = '\0';
  56                 if (c == '\n')
  57                         return pos;
  58         }
  59 }