libio/iogetline.c

   1 /* Copyright (C) 1993,1997,1998,2000,2001,2002,2005
   2    Free Software Foundation, Inc.
   3    This file is part of the GNU C Library.
   4
   5    The GNU C Library is free software; you can redistribute it and/or
   6    modify it under the terms of the GNU Lesser General Public
   7    License as published by the Free Software Foundation; either
   8    version 2.1 of the License, or (at your option) any later version.
   9
  10    The GNU C 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 GNU
  13    Lesser General Public License for more details.
  14
  15    You should have received a copy of the GNU Lesser General Public
  16    License along with the GNU C Library; if not, write to the Free
  17    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
  18    02111-1307 USA.
  19
  20    As a special exception, if you link the code in this file with
  21    files compiled with a GNU compiler to produce an executable,
  22    that does not cause the resulting executable to be covered by
  23    the GNU Lesser General Public License.  This exception does not
  24    however invalidate any other reasons why the executable file
  25    might be covered by the GNU Lesser General Public License.
  26    This exception applies to code released by its copyright holders
  27    in files containing the exception.  */
  28
  29 #include "libioP.h"
  30 #include <string.h>
  31
  32 #if defined _LIBC || !_G_HAVE_IO_GETLINE_INFO
  33
  34 _IO_size_t
  35 _IO_getline (fp, buf, n, delim, extract_delim)
  36      _IO_FILE *fp;
  37      char *buf;
  38      _IO_size_t n;
  39      int delim;
  40      int extract_delim;
  41 {
  42   return INTUSE(_IO_getline_info) (fp, buf, n, delim, extract_delim,
  43                                    (int *) 0);
  44 }
  45 INTDEF(_IO_getline)
  46
  47 /* Algorithm based on that used by Berkeley pre-4.4 fgets implementation.
  48
  49    Read chars into buf (of size n), until delim is seen.
  50    Return number of chars read (at most n).
  51    Does not put a terminating '\0' in buf.
  52    If extract_delim < 0, leave delimiter unread.
  53    If extract_delim > 0, insert delim in output. */
  54
  55 _IO_size_t
  56 _IO_getline_info (fp, buf, n, delim, extract_delim, eof)
  57      _IO_FILE *fp;
  58      char *buf;
  59      _IO_size_t n;
  60      int delim;
  61      int extract_delim;
  62      int *eof;
  63 {
  64   char *ptr = buf;
  65   if (eof != NULL)
  66     *eof = 0;
  67   if (__builtin_expect (fp->_mode, -1) == 0)
  68     _IO_fwide (fp, -1);
  69   while (n != 0)
  70     {
  71       _IO_ssize_t len = fp->_IO_read_end - fp->_IO_read_ptr;
  72       if (len <= 0)
  73         {
  74           int c = __uflow (fp);
  75           if (c == EOF)
  76             {
  77               if (eof)
  78                 *eof = c;
  79               break;
  80             }
  81           if (c == delim)
  82             {
  83               if (extract_delim > 0)
  84                 *ptr++ = c;
  85               else if (extract_delim < 0)
  86                 INTUSE(_IO_sputbackc) (fp, c);
  87               if (extract_delim > 0)
  88                 ++len;
  89               return ptr - buf;
  90             }
  91           *ptr++ = c;
  92           n--;
  93         }
  94       else
  95         {
  96           char *t;
  97           if ((_IO_size_t) len >= n)
  98             len = n;
  99           t = (char *) memchr ((void *) fp->_IO_read_ptr, delim, len);
 100           if (t != NULL)
 101             {
 102               _IO_size_t old_len = ptr-buf;
 103               len = t - fp->_IO_read_ptr;
 104               if (extract_delim >= 0)
 105                 {
 106                   ++t;
 107                   if (extract_delim > 0)
 108                     ++len;
 109                 }
 110               memcpy ((void *) ptr, (void *) fp->_IO_read_ptr, len);
 111               fp->_IO_read_ptr = t;
 112               return old_len + len;
 113             }
 114           memcpy ((void *) ptr, (void *) fp->_IO_read_ptr, len);
 115           fp->_IO_read_ptr += len;
 116           ptr += len;
 117           n -= len;
 118         }
 119     }
 120   return ptr - buf;
 121 }
 122 INTDEF(_IO_getline_info)
 123
 124 #endif /* Defined _LIBC || !_G_HAVE_IO_GETLINE_INFO */