libio/iogetdelim.c

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