compat/fgetln.c

   1 /*
   2  * Copyright (c) 2015 Joerg Jung <jung@openbsd.org>
   3  *
   4  * Permission to use, copy, modify, and distribute this software for any
   5  * purpose with or without fee is hereby granted, provided that the above
   6  * copyright notice and this permission notice appear in all copies.
   7  *
   8  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
   9  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
  10  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
  11  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
  12  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
  13  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
  14  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  15  */
  16
  17 /*
  18  * portable fgetln() version, NOT reentrant
  19  */
  20
  21 #include <stdio.h>
  22 #include <stdlib.h>
  23 #include <errno.h>
  24
  25 #include "compat.h"
  26
  27 char *
  28 fgetln(FILE *fp, size_t *len)
  29 {
  30         static char *buf = NULL;
  31         static size_t bufsz = 0;
  32         size_t r = 0;
  33         char *p;
  34         int c, e;
  35
  36         if (!fp || !len) {
  37                 errno = EINVAL;
  38                 return NULL;
  39         }
  40         if (!buf) {
  41                 if (!(buf = calloc(1, BUFSIZ)))
  42                         return NULL;
  43                 bufsz = BUFSIZ;
  44         }
  45         while ((c = getc(fp)) != EOF) {
  46                 buf[r++] = c;
  47                 if (r == bufsz) {
  48                         if (!(p = reallocarray(buf, 2, bufsz))) {
  49                                 e = errno;
  50                                 free(buf);
  51                                 errno = e;
  52                                 buf = NULL, bufsz = 0;
  53                                 return NULL;
  54                         }
  55                         buf = p, bufsz = 2 * bufsz;
  56                 }
  57                 if (c == '\n')
  58                         break;
  59         }
  60         return (*len = r) ? buf : NULL;
  61 }