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/*
* 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>
char *
_DEFUN(_gets_r, (ptr, buf),
struct _reent *ptr _AND
char *buf)
{
register int c;
register char *s = buf;
__sfp_lock_acquire ();
_flockfile (stdin);
while ((c = __sgetc_r (ptr, stdin)) != '\n')
if (c == EOF)
if (s == buf)
{
_funlockfile (stdin);
__sfp_lock_release ();
return NULL;
}
else
break;
else
*s++ = c;
*s = 0;
_funlockfile (stdin);
__sfp_lock_release ();
return buf;
}
#ifndef _REENT_ONLY
char *
_DEFUN(gets, (buf),
char *buf)
{
return _gets_r (_REENT, buf);
}
#endif
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