Subversion Repositories Kolibri OS

/*

 * Copyright (c) 1990 The Regents of the University of California.

 * All rights reserved.

 *

 * Redistribution and use in source and binary forms are permitted

 * provided that the above copyright notice and this paragraph are

 * duplicated in all such forms and that any documentation,

 * advertising materials, and other materials related to such

 * distribution and use acknowledge that the software was developed

 * by the University of California, Berkeley.  The name of the

 * University may not be used to endorse or promote products derived

 * from this software without specific prior written permission.

 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR

 * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED

 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.

 */

/*

FUNCTION

<>, <>---get character string from a file or stream

INDEX

	fgets

INDEX

	fgets_unlocked

INDEX

	_fgets_r

INDEX

	_fgets_unlocked_r

ANSI_SYNOPSIS

        #include 

	char *fgets(char *restrict <[buf]>, int <[n]>, FILE *restrict <[fp]>);

	#define _GNU_SOURCE

        #include 

	char *fgets_unlocked(char *restrict <[buf]>, int <[n]>, FILE *restrict <[fp]>);

        #include 

	char *_fgets_r(struct _reent *<[ptr]>, char *restrict <[buf]>, int <[n]>, FILE *restrict <[fp]>);

        #include 

	char *_fgets_unlocked_r(struct _reent *<[ptr]>, char *restrict <[buf]>, int <[n]>, FILE *restrict <[fp]>);

TRAD_SYNOPSIS

	#include 

	char *fgets(<[buf]>,<[n]>,<[fp]>)

        char *<[buf]>;

	int <[n]>;

	FILE *<[fp]>;

	#define _GNU_SOURCE

	#include 

	char *fgets_unlocked(<[buf]>,<[n]>,<[fp]>)

        char *<[buf]>;

	int <[n]>;

	FILE *<[fp]>;

	#include 

	char *_fgets_r(<[ptr]>, <[buf]>,<[n]>,<[fp]>)

	struct _reent *<[ptr]>;

        char *<[buf]>;

	int <[n]>;

	FILE *<[fp]>;

	#include 

	char *_fgets_unlocked_r(<[ptr]>, <[buf]>,<[n]>,<[fp]>)

	struct _reent *<[ptr]>;

        char *<[buf]>;

	int <[n]>;

	FILE *<[fp]>;

DESCRIPTION

	Reads at most <[n-1]> characters from <[fp]> until a newline

	is found. The characters including to the newline are stored

	in <[buf]>. The buffer is terminated with a 0.

	<> is a non-thread-safe version of <>.

	<> may only safely be used within a scope

	protected by flockfile() (or ftrylockfile()) and funlockfile().  This

	function may safely be used in a multi-threaded program if and only

	if they are called while the invoking thread owns the (FILE *)

	object, as is the case after a successful call to the flockfile() or

	ftrylockfile() functions.  If threads are disabled, then

	<> is equivalent to <>.

	The functions <<_fgets_r>> and <<_fgets_unlocked_r>> are simply

	reentrant versions that are passed the additional reentrant structure

	pointer argument: <[ptr]>.

RETURNS

	<> returns the buffer passed to it, with the data

	filled in. If end of file occurs with some data already

	accumulated, the data is returned with no other indication. If

	no data are read, NULL is returned instead.

PORTABILITY

	<> should replace all uses of <>. Note however

	that <> returns all of the data, while <> removes

	the trailing newline (with no indication that it has done so.)

	<> is a GNU extension.

Supporting OS subroutines required: <>, <>, <>,

<>, <>, <>, <>.

*/

#include <_ansi.h>

#include 

#include 

#include "local.h"

#ifdef __IMPL_UNLOCKED__

#define _fgets_r _fgets_unlocked_r

#define fgets fgets_unlocked

#endif

/*

 * Read at most n-1 characters from the given file.

 * Stop when a newline has been read, or the count runs out.

 * Return first argument, or NULL if no characters were read.

 */

char *

_DEFUN(_fgets_r, (ptr, buf, n, fp),

       struct _reent * ptr _AND

       char *__restrict buf _AND

       int n     _AND

       FILE *__restrict fp)

{

  size_t len;

  char *s;

  unsigned char *p, *t;

  if (n < 2)			/* sanity check */

    return 0;

  s = buf;

  CHECK_INIT(ptr, fp);

  _newlib_flockfile_start (fp);

#ifdef __SCLE

  if (fp->_flags & __SCLE)

    {

      int c = 0;

      /* Sorry, have to do it the slow way */

      while (--n > 0 && (c = __sgetc_r (ptr, fp)) != EOF)

	{

	  *s++ = c;

	  if (c == '\n')

	    break;

	}

      if (c == EOF && s == buf)

        {

          _newlib_flockfile_exit (fp);

          return NULL;

        }

      *s = 0;

      _newlib_flockfile_exit (fp);

      return buf;

    }

#endif

  n--;				/* leave space for NUL */

  do

    {

      /*

       * If the buffer is empty, refill it.

       */

      if ((len = fp->_r) <= 0)

	{

	  if (__srefill_r (ptr, fp))

	    {

	      /* EOF: stop with partial or no line */

	      if (s == buf)

                {

                  _newlib_flockfile_exit (fp);

                  return 0;

                }

	      break;

	    }

	  len = fp->_r;

	}

      p = fp->_p;

      /*

       * Scan through at most n bytes of the current buffer,

       * looking for '\n'.  If found, copy up to and including

       * newline, and stop.  Otherwise, copy entire chunk

       * and loop.

       */

      if (len > n)

	len = n;

      t = (unsigned char *) memchr ((_PTR) p, '\n', len);

      if (t != 0)

	{

	  len = ++t - p;

	  fp->_r -= len;

	  fp->_p = t;

	  _CAST_VOID memcpy ((_PTR) s, (_PTR) p, len);

	  s[len] = 0;

          _newlib_flockfile_exit (fp);

	  return (buf);

	}

      fp->_r -= len;

      fp->_p += len;

      _CAST_VOID memcpy ((_PTR) s, (_PTR) p, len);

      s += len;

    }

  while ((n -= len) != 0);

  *s = 0;

  _newlib_flockfile_end (fp);

  return buf;

}

#ifndef _REENT_ONLY

char *

_DEFUN(fgets, (buf, n, fp),

       char *__restrict buf _AND

       int n     _AND

       FILE *__restrict fp)

{

  return _fgets_r (_REENT, buf, n, fp);

}

#endif /* !_REENT_ONLY */