source: trunk/third/gnome-vfs/libgnomevfs/getdelim.c @ 15497

/* Copyright (C) 1991, 1992, 1995, 1996, 1997 Free Software Foundation, Inc.
   This file is part of the GNU C Library.

   The GNU C Library is free software; you can redistribute it and/or
   modify it under the terms of the GNU Library General Public License as
   published by the Free Software Foundation; either version 2 of the
   License, or (at your option) any later version.

   The GNU C Library is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
   Library General Public License for more details.

   You should have received a copy of the GNU Library General Public
   License along with the GNU C Library; see the file COPYING.LIB.  If not,
   write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
   Boston, MA 02111-1307, USA.  */

#include <stddef.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <limits.h>
#include <errno.h>

/* Read up to (and including) a TERMINATOR from STREAM into *LINEPTR
   (and null-terminate it). *LINEPTR is a pointer returned from malloc (or
   NULL), pointing to *N characters of space.  It is realloc'd as
   necessary.  Returns the number of characters read (not including the
   null terminator), or -1 on error or EOF.  */

ssize_t
getdelim (lineptr, n, terminator, stream)
     char **lineptr;
     size_t *n;
     int terminator;
     FILE *stream;
{
  char *line, *p;
  size_t size, copy;

  if (!__validfp (stream) || lineptr == NULL || n == NULL)
    {
      __set_errno (EINVAL);
      return -1;
    }

  if (ferror (stream))
    return -1;

  /* Make sure we have a line buffer to start with.  */
  if (*lineptr == NULL || *n < 2) /* !seen and no buf yet need 2 chars.  */
    {
#ifndef MAX_CANON
#define MAX_CANON       256
#endif
      line = realloc (*lineptr, MAX_CANON);
      if (line == NULL)
        return -1;
      *lineptr = line;
      *n = MAX_CANON;
    }

  line = *lineptr;
  size = *n;

  copy = size;
  p = line;

  if (stream->__buffer == NULL && stream->__userbuf)
    {
      /* Unbuffered stream.  Not much optimization to do.  */

      while (1)
        {
          size_t len;

          while (--copy > 0)
            {
              register int c = getc (stream);
              if (c == EOF)
                goto lose;
              else if ((*p++ = c) == terminator)
                goto win;
            }

          /* Need to enlarge the line buffer.  */
          len = p - line;
          size *= 2;
          line = realloc (line, size);
          if (line == NULL)
            goto lose;
          *lineptr = line;
          *n = size;
          p = line + len;
          copy = size - len;
        }
    }
  else
    {
      /* Leave space for the terminating null.  */
      --copy;

      if (!stream->__seen || stream->__buffer == NULL || stream->__pushed_back)
        {
          /* Do one with getc to allocate a buffer.  */
          int c = getc (stream);
          if (c == EOF)
            goto lose;
          *p++ = c;
          if (c == terminator)
            goto win;
          --copy;
        }

      while (1)
        {
          size_t i;
          char *found;

          i = stream->__get_limit - stream->__bufp;
          if (i == 0)
            {
              /* Refill the buffer.  */
              int c = __fillbf (stream);
              if (c == EOF)
                goto lose;
              *p++ = c;
              if (c == terminator)
                goto win;
              --copy;
              i = stream->__get_limit - stream->__bufp;
            }

          if (i > copy)
            i = copy;

          found = (char *) __memccpy ((void *) p, stream->__bufp, 
                                      terminator, i);
          if (found != NULL)
            {
              stream->__bufp += found - p;
              p = found;
              goto win;
            }

          stream->__bufp += i;
          p += i;
          copy -= i;
          if (copy == 0)
            {
              /* Need to enlarge the line buffer.  */
              size_t len = p - line;
              size *= 2;
              line = realloc (line, size);
              if (line == NULL)
                goto lose;
              *lineptr = line;
              *n = size;
              p = line + len;
              copy = size - len;
              /* Leave space for the terminating null.  */
              --copy;
            }
        }
    }

 lose:
  if (p == *lineptr)
    return -1;
  /* Return a partial line since we got an error in the middle.  */
 win:
  *p = '\0';
  return p - *lineptr;
}

weak_alias (__getdelim, getdelim)