libio/iogetdelim.c

   1 /*
   2 Copyright (C) 1994 Free Software Foundation
   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 #ifdef EINVAL
  52       errno = EINVAL;
  53 #endif
  54       return -1;
  55     }
  56   CHECK_FILE (fp, -1);
  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   return result;
 120 }
 121
 122 weak_alias (_IO_getdelim, __getdelim)
 123 weak_alias (_IO_getdelim, getdelim)