114 lines
2.9 KiB
C
114 lines
2.9 KiB
C
/*
|
|
* 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
|
|
<<gets>>---get character string (obsolete, use <<fgets>> instead)
|
|
|
|
INDEX
|
|
gets
|
|
INDEX
|
|
_gets_r
|
|
|
|
ANSI_SYNOPSIS
|
|
#include <stdio.h>
|
|
|
|
char *gets(char *<[buf]>);
|
|
|
|
char *_gets_r(struct _reent *<[reent]>, char *<[buf]>);
|
|
|
|
TRAD_SYNOPSIS
|
|
#include <stdio.h>
|
|
|
|
char *gets(<[buf]>)
|
|
char *<[buf]>;
|
|
|
|
char *_gets_r(<[reent]>, <[buf]>)
|
|
struct _reent *<[reent]>;
|
|
char *<[buf]>;
|
|
|
|
DESCRIPTION
|
|
Reads characters from standard input until a newline is found.
|
|
The characters up to the newline are stored in <[buf]>. The
|
|
newline is discarded, and the buffer is terminated with a 0.
|
|
|
|
This is a @emph{dangerous} function, as it has no way of checking
|
|
the amount of space available in <[buf]>. One of the attacks
|
|
used by the Internet Worm of 1988 used this to overrun a
|
|
buffer allocated on the stack of the finger daemon and
|
|
overwrite the return address, causing the daemon to execute
|
|
code downloaded into it over the connection.
|
|
|
|
The alternate function <<_gets_r>> is a reentrant version. The extra
|
|
argument <[reent]> is a pointer to a reentrancy structure.
|
|
|
|
|
|
RETURNS
|
|
<<gets>> 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 end of file
|
|
occurs with no data in the buffer, NULL is returned.
|
|
|
|
Supporting OS subroutines required: <<close>>, <<fstat>>, <<isatty>>,
|
|
<<lseek>>, <<read>>, <<sbrk>>, <<write>>.
|
|
*/
|
|
|
|
#include <_ansi.h>
|
|
#include <reent.h>
|
|
#include <stdio.h>
|
|
#include "local.h"
|
|
|
|
char *
|
|
_DEFUN(_gets_r, (ptr, buf),
|
|
struct _reent *ptr _AND
|
|
char *buf)
|
|
{
|
|
register int c;
|
|
register char *s = buf;
|
|
FILE *fp;
|
|
|
|
_REENT_SMALL_CHECK_INIT (ptr);
|
|
fp = _stdin_r (ptr);
|
|
CHECK_INIT (ptr, fp);
|
|
_newlib_flockfile_start (fp);
|
|
while ((c = __sgetc_r (ptr, fp)) != '\n')
|
|
if (c == EOF)
|
|
if (s == buf)
|
|
{
|
|
_newlib_flockfile_exit (fp);
|
|
return NULL;
|
|
}
|
|
else
|
|
break;
|
|
else
|
|
*s++ = c;
|
|
*s = 0;
|
|
_newlib_flockfile_end (fp);
|
|
return buf;
|
|
}
|
|
|
|
#ifndef _REENT_ONLY
|
|
|
|
char *
|
|
_DEFUN(gets, (buf),
|
|
char *buf)
|
|
{
|
|
return _gets_r (_REENT, buf);
|
|
}
|
|
|
|
#endif
|