lib/getdelim.c

   1 /* Taken from uClibc and adapted to GLiv */
   2
   3 /* Copyright (C) 2004       Manuel Novoa III    <mjn3@codepoet.org>
   4  *
   5  * GNU Library General Public License (LGPL) version 2 or later.
   6  *
   7  * Dedicated to Toni.  See uClibc/DEDICATION.mjn3 for details.
   8  */
   9
  10 #include "stdio.h"
  11 #include "stdlib.h"
  12 #include "getdelim.h"
  13
  14 /* Note: There is a defect in this function.  (size_t vs long). */
  15
  16 /* glibc function --
  17  * Return -1 if error or EOF prior to any chars read.
  18  * Return number of chars read (including possible delimiter but not
  19  *   the terminating nul) otherwise.
  20  *
  21  * NOTE: If we need to allocate a buffer, we do so prior to attempting
  22  * a reading.  So space may be allocated even if initially at EOF.
  23  */
  24 #define GETDELIM_GROWBY 64
  25 long getdelim(char ** lineptr, size_t * n,
  26               int delimiter, FILE * stream)
  27 {
  28         char *buf;
  29         long pos = -1;
  30         int c;
  31
  32         if (lineptr && n && stream) {
  33                 if (!(buf = *lineptr)) { /* If passed NULL for buffer, */
  34                         *n = 0;         /* ignore value passed and treat size as 0. */
  35                 }
  36
  37                 /* Within the loop, pos is actually the current buffer index + 2,
  38                  * because we want to make sure we have enough space to store
  39                  * an additional char plus a nul terminator.
  40                  */
  41                 pos = 1;
  42
  43                 do {
  44                         if (pos >= *n) {
  45                                 if (!(buf = realloc(buf, *n + GETDELIM_GROWBY))) {
  46                                         pos = -1;
  47                                         break;
  48                                 }
  49                                 *n += GETDELIM_GROWBY;
  50                                 *lineptr = buf;
  51                         }
  52
  53                         if ((c = fgetc(stream)) != EOF) {
  54                                 buf[++pos - 2] = c;
  55                                 if (c != delimiter) {
  56                                         continue;
  57                                 }
  58                         }
  59
  60                         /* We're done, so correct pos back to being the current index. */
  61                         if ((pos -= 2) >= 0) {
  62                                 buf[++pos] = 0;
  63                         }
  64                         break;
  65
  66                 } while (1);
  67         }
  68
  69         return pos;
  70 }