libio/iogetdelim.c

   1 /* Copyright (C) 1994,1996-1998,2001,2003,2005 Free Software Foundation, Inc.
   2    This file is part of the GNU C Library.
   3
   4    The GNU C Library is free software; you can redistribute it and/or
   5    modify it under the terms of the GNU Lesser General Public
   6    License as published by the Free Software Foundation; either
   7    version 2.1 of the License, or (at your option) any later version.
   8
   9    The GNU C Library is distributed in the hope that it will be useful,
  10    but WITHOUT ANY WARRANTY; without even the implied warranty of
  11    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  12    Lesser General Public License for more details.
  13
  14    You should have received a copy of the GNU Lesser General Public
  15    License along with the GNU C Library; if not, write to the Free
  16    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
  17    02111-1307 USA.
  18
  19    As a special exception, if you link the code in this file with
  20    files compiled with a GNU compiler to produce an executable,
  21    that does not cause the resulting executable to be covered by
  22    the GNU Lesser General Public License.  This exception does not
  23    however invalidate any other reasons why the executable file
  24    might be covered by the GNU Lesser General Public License.
  25    This exception applies to code released by its copyright holders
  26    in files containing the exception.  */
  27
  28 #ifdef __STDC__
  29 #include <stdlib.h>
  30 #endif
  31 #include "libioP.h"
  32 #include <string.h>
  33 #include <errno.h>
  34
  35 /* Read up to (and including) a TERMINATOR from FP into *LINEPTR
  36    (and null-terminate it).  *LINEPTR is a pointer returned from malloc (or
  37    NULL), pointing to *N characters of space.  It is realloc'ed as
  38    necessary.  Returns the number of characters read (not including the
  39    null terminator), or -1 on error or EOF.  */
  40
  41 _IO_ssize_t
  42 _IO_getdelim (lineptr, n, delimiter, fp)
  43      char **lineptr;
  44      _IO_size_t *n;
  45      int delimiter;
  46      _IO_FILE *fp;
  47 {
  48   _IO_ssize_t result;
  49   _IO_ssize_t cur_len = 0;
  50   _IO_ssize_t len;
  51
  52   if (lineptr == NULL || n == NULL)
  53     {
  54       MAYBE_SET_EINVAL;
  55       return -1;
  56     }
  57   CHECK_FILE (fp, -1);
  58   _IO_acquire_lock (fp);
  59   if (_IO_ferror_unlocked (fp))
  60     {
  61       result = -1;
  62       goto unlock_return;
  63     }
  64
  65   if (*lineptr == NULL || *n == 0)
  66     {
  67       *n = 120;
  68       *lineptr = (char *) malloc (*n);
  69       if (*lineptr == NULL)
  70         {
  71           result = -1;
  72           goto unlock_return;
  73         }
  74     }
  75
  76   len = fp->_IO_read_end - fp->_IO_read_ptr;
  77   if (len <= 0)
  78     {
  79       if (__underflow (fp) == EOF)
  80         {
  81           result = -1;
  82           goto unlock_return;
  83         }
  84       len = fp->_IO_read_end - fp->_IO_read_ptr;
  85     }
  86
  87   for (;;)
  88     {
  89       _IO_size_t needed;
  90       char *t;
  91       t = (char *) memchr ((void *) fp->_IO_read_ptr, delimiter, len);
  92       if (t != NULL)
  93         len = (t - fp->_IO_read_ptr) + 1;
  94       if (__builtin_expect (cur_len + len + 1 < 0, 0))
  95         {
  96           __set_errno (EOVERFLOW);
  97           result = -1;
  98           goto unlock_return;
  99         }
 100       /* Make enough space for len+1 (for final NUL) bytes.  */
 101       needed = cur_len + len + 1;
 102       if (needed > *n)
 103         {
 104           char *new_lineptr;
 105
 106           if (needed < 2 * *n)
 107             needed = 2 * *n;  /* Be generous. */
 108           new_lineptr = (char *) realloc (*lineptr, needed);
 109           if (new_lineptr == NULL)
 110             {
 111               result = -1;
 112               goto unlock_return;
 113             }
 114           *lineptr = new_lineptr;
 115           *n = needed;
 116         }
 117       memcpy (*lineptr + cur_len, (void *) fp->_IO_read_ptr, len);
 118       fp->_IO_read_ptr += len;
 119       cur_len += len;
 120       if (t != NULL || __underflow (fp) == EOF)
 121         break;
 122       len = fp->_IO_read_end - fp->_IO_read_ptr;
 123     }
 124   (*lineptr)[cur_len] = '\0';
 125   result = cur_len;
 126
 127 unlock_return:
 128   _IO_release_lock (fp);
 129   return result;
 130 }
 131
 132 #ifdef weak_alias
 133 weak_alias (_IO_getdelim, __getdelim)
 134 weak_alias (_IO_getdelim, getdelim)
 135 #endif