contrib/cvs-1.12/lib/getdelim.c

   1 /* getdelim.c --- Implementation of replacement getdelim function.
   2    Copyright (C) 1994, 1996, 1997, 1998, 2001, 2003, 2005 Free
   3    Software Foundation, Inc.
   4
   5    This program is free software; you can redistribute it and/or
   6    modify it under the terms of the GNU General Public License as
   7    published by the Free Software Foundation; either version 2, or (at
   8    your option) any later version.
   9
  10    This program is distributed in the hope that it will be useful, but
  11    WITHOUT ANY WARRANTY; without even the implied warranty of
  12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13    General Public License for more details.
  14
  15    You should have received a copy of the GNU General Public License
  16    along with this program; if not, write to the Free Software
  17    Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
  18    02110-1301, USA.  */
  19
  20 /* Ported from glibc by Simon Josefsson. */
  21
  22 #ifdef HAVE_CONFIG_H
  23 # include <config.h>
  24 #endif
  25
  26 #include <stdlib.h>
  27 #include <errno.h>
  28
  29 #include "getdelim.h"
  30
  31 #if !HAVE_FLOCKFILE
  32 # undef flockfile
  33 # define flockfile(x) ((void) 0)
  34 #endif
  35 #if !HAVE_FUNLOCKFILE
  36 # undef funlockfile
  37 # define funlockfile(x) ((void) 0)
  38 #endif
  39
  40 /* Read up to (and including) a DELIMITER from FP into *LINEPTR (and
  41    NUL-terminate it).  *LINEPTR is a pointer returned from malloc (or
  42    NULL), pointing to *N characters of space.  It is realloc'ed as
  43    necessary.  Returns the number of characters read (not including
  44    the null terminator), or -1 on error or EOF.  */
  45
  46 ssize_t
  47 getdelim (char **lineptr, size_t *n, int delimiter, FILE *fp)
  48 {
  49   int result = 0;
  50   ssize_t cur_len = 0;
  51   ssize_t len;
  52
  53   if (lineptr == NULL || n == NULL || fp == NULL)
  54     {
  55       errno = EINVAL;
  56       return -1;
  57     }
  58
  59   flockfile (fp);
  60
  61   if (*lineptr == NULL || *n == 0)
  62     {
  63       *n = 120;
  64       *lineptr = (char *) malloc (*n);
  65       if (*lineptr == NULL)
  66         {
  67           result = -1;
  68           goto unlock_return;
  69         }
  70     }
  71
  72   for (;;)
  73     {
  74       char *t;
  75       int i;
  76
  77       i = getc (fp);
  78       if (i == EOF)
  79       {
  80         result = -1;
  81         break;
  82       }
  83
  84       /* Make enough space for len+1 (for final NUL) bytes.  */
  85       if (cur_len + 1 >= *n)
  86         {
  87           size_t needed = 2 * (cur_len + 1) + 1;   /* Be generous. */
  88           char *new_lineptr;
  89
  90           if (needed < cur_len)
  91             {
  92               result = -1;
  93               goto unlock_return;
  94             }
  95
  96           new_lineptr = (char *) realloc (*lineptr, needed);
  97           if (new_lineptr == NULL)
  98             {
  99               result = -1;
 100               goto unlock_return;
 101             }
 102
 103           *lineptr = new_lineptr;
 104           *n = needed;
 105         }
 106
 107       (*lineptr)[cur_len] = i;
 108       cur_len++;
 109
 110       if (i == delimiter)
 111         break;
 112     }
 113   (*lineptr)[cur_len] = '\0';
 114   result = cur_len ? cur_len : result;
 115
 116  unlock_return:
 117   funlockfile (fp);
 118   return result;
 119 }