libio/iogetdelim.c

   1 /* Copyright (C) 1994, 1996, 1997, 1998 Free Software Foundation, Inc.
   2    This file is part of the GNU IO Library.
   3
   4    This library is free software; you can redistribute it and/or
   5    modify it under the terms of the GNU General Public License as
   6    published by the Free Software Foundation; either version 2, or (at
   7    your option) any later version.
   8
   9    This library is distributed in the hope that it will be useful, but
  10    WITHOUT ANY WARRANTY; without even the implied warranty of
  11    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  12    General Public License for more details.
  13
  14    You should have received a copy of the GNU General Public License
  15    along with this library; see the file COPYING.  If not, write to
  16    the Free Software Foundation, 59 Temple Place - Suite 330, Boston,
  17    MA 02111-1307, USA.
  18
  19    As a special exception, if you link this library with files
  20    compiled with a GNU compiler to produce an executable, this does
  21    not cause the resulting executable to be covered by the GNU General
  22    Public License.  This exception does not however invalidate any
  23    other reasons why the executable file might be covered by the GNU
  24    General Public License.  */
  25
  26 #ifdef __STDC__
  27 #include <stdlib.h>
  28 #endif
  29 #include "libioP.h"
  30 #include <string.h>
  31 #include <errno.h>
  32
  33 /* Read up to (and including) a TERMINATOR from FP into *LINEPTR
  34    (and null-terminate it).  *LINEPTR is a pointer returned from malloc (or
  35    NULL), pointing to *N characters of space.  It is realloc'ed as
  36    necessary.  Returns the number of characters read (not including the
  37    null terminator), or -1 on error or EOF.  */
  38
  39 _IO_ssize_t
  40 _IO_getdelim (lineptr, n, delimiter, fp)
  41      char **lineptr;
  42      _IO_size_t *n;
  43      int delimiter;
  44      _IO_FILE *fp;
  45 {
  46   int result;
  47   _IO_ssize_t cur_len = 0;
  48   _IO_ssize_t len;
  49
  50   if (lineptr == NULL || n == NULL)
  51     {
  52       MAYBE_SET_EINVAL;
  53       return -1;
  54     }
  55   CHECK_FILE (fp, -1);
  56   _IO_cleanup_region_start ((void (*) __P ((void *))) _IO_funlockfile, fp);
  57   _IO_flockfile (fp);
  58   if (_IO_ferror_unlocked (fp))
  59     {
  60       result = -1;
  61       goto unlock_return;
  62     }
  63
  64   if (*lineptr == NULL || *n == 0)
  65     {
  66       *n = 120;
  67       *lineptr = (char *) malloc (*n);
  68       if (*lineptr == NULL)
  69         {
  70           result = -1;
  71           goto unlock_return;
  72         }
  73     }
  74
  75   len = fp->_IO_read_end - fp->_IO_read_ptr;
  76   if (len <= 0)
  77     {
  78       if (__underflow (fp) == EOF)
  79         {
  80           result = -1;
  81           goto unlock_return;
  82         }
  83       len = fp->_IO_read_end - fp->_IO_read_ptr;
  84     }
  85
  86   for (;;)
  87     {
  88       _IO_size_t needed;
  89       char *t;
  90       t = (char *) memchr ((void *) fp->_IO_read_ptr, delimiter, len);
  91       if (t != NULL)
  92         len = (t - fp->_IO_read_ptr) + 1;
  93       /* Make enough space for len+1 (for final NUL) bytes.  */
  94       needed = cur_len + len + 1;
  95       if (needed > *n)
  96         {
  97           if (needed < 2 * *n)
  98             needed = 2 * *n;  /* Be generous. */
  99           *n = needed;
 100           *lineptr = (char *) realloc (*lineptr, needed);
 101           if (*lineptr == NULL)
 102             {
 103               result = -1;
 104               goto unlock_return;
 105             }
 106         }
 107       memcpy (*lineptr + cur_len, (void *) fp->_IO_read_ptr, len);
 108       fp->_IO_read_ptr += len;
 109       cur_len += len;
 110       if (t != NULL || __underflow (fp) == EOF)
 111         break;
 112       len = fp->_IO_read_end - fp->_IO_read_ptr;
 113     }
 114   (*lineptr)[cur_len] = '\0';
 115   result = cur_len;
 116
 117 unlock_return:
 118   _IO_funlockfile (fp);
 119   _IO_cleanup_region_end (0);
 120   return result;
 121 }
 122
 123 #ifdef weak_alias
 124 weak_alias (_IO_getdelim, __getdelim)
 125 weak_alias (_IO_getdelim, getdelim)
 126 #endif