1  /* Copyright (C) 1993-2023 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, see
      16     <https://www.gnu.org/licenses/>.
      17  
      18     As a special exception, if you link the code in this file with
      19     files compiled with a GNU compiler to produce an executable,
      20     that does not cause the resulting executable to be covered by
      21     the GNU Lesser General Public License.  This exception does not
      22     however invalidate any other reasons why the executable file
      23     might be covered by the GNU Lesser General Public License.
      24     This exception applies to code released by its copyright holders
      25     in files containing the exception.  */
      26  
      27  #include "libioP.h"
      28  #include <string.h>
      29  
      30  size_t
      31  _IO_getline (FILE *fp, char *buf, size_t n, int delim,
      32  	     int extract_delim)
      33  {
      34    return _IO_getline_info (fp, buf, n, delim, extract_delim, (int *) 0);
      35  }
      36  libc_hidden_def (_IO_getline)
      37  
      38  /* Algorithm based on that used by Berkeley pre-4.4 fgets implementation.
      39  
      40     Read chars into buf (of size n), until delim is seen.
      41     Return number of chars read (at most n).
      42     Does not put a terminating '\0' in buf.
      43     If extract_delim < 0, leave delimiter unread.
      44     If extract_delim > 0, insert delim in output. */
      45  
      46  size_t
      47  _IO_getline_info (FILE *fp, char *buf, size_t n, int delim,
      48  		  int extract_delim, int *eof)
      49  {
      50    char *ptr = buf;
      51    if (eof != NULL)
      52      *eof = 0;
      53    if (__builtin_expect (fp->_mode, -1) == 0)
      54      _IO_fwide (fp, -1);
      55    while (n != 0)
      56      {
      57        ssize_t len = fp->_IO_read_end - fp->_IO_read_ptr;
      58        if (len <= 0)
      59  	{
      60  	  int c = __uflow (fp);
      61  	  if (c == EOF)
      62  	    {
      63  	      if (eof)
      64  		*eof = c;
      65  	      break;
      66  	    }
      67  	  if (c == delim)
      68  	    {
      69   	      if (extract_delim > 0)
      70  		*ptr++ = c;
      71  	      else if (extract_delim < 0)
      72  		_IO_sputbackc (fp, c);
      73  	      if (extract_delim > 0)
      74  		++len;
      75  	      return ptr - buf;
      76  	    }
      77  	  *ptr++ = c;
      78  	  n--;
      79  	}
      80        else
      81  	{
      82  	  char *t;
      83  	  if ((size_t) len >= n)
      84  	    len = n;
      85  	  t = (char *) memchr ((void *) fp->_IO_read_ptr, delim, len);
      86  	  if (t != NULL)
      87  	    {
      88  	      size_t old_len = ptr-buf;
      89  	      len = t - fp->_IO_read_ptr;
      90  	      if (extract_delim >= 0)
      91  		{
      92  		  ++t;
      93  		  if (extract_delim > 0)
      94  		    ++len;
      95  		}
      96  	      memcpy ((void *) ptr, (void *) fp->_IO_read_ptr, len);
      97  	      fp->_IO_read_ptr = t;
      98  	      return old_len + len;
      99  	    }
     100  	  memcpy ((void *) ptr, (void *) fp->_IO_read_ptr, len);
     101  	  fp->_IO_read_ptr += len;
     102  	  ptr += len;
     103  	  n -= len;
     104  	}
     105      }
     106    return ptr - buf;
     107  }
     108  libc_hidden_def (_IO_getline_info)