glibc/stdio/gets.c

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1995-02-18 09:27:10 +08:00
/* Copyright (C) 1991, 1994, 1995 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., 675 Mass Ave,
Cambridge, MA 02139, USA. */
#include <ansidecl.h>
#include <stdio.h>
#include <errno.h>
#include <string.h>
link_warning ("the `gets' function is unreliable and should not be used.")
/* Read a newline-terminated string from stdin into S,
removing the trailing newline. Return S or NULL. */
char *
DEFUN(gets, (s), char *s)
{
register char *p = s;
register int c;
FILE *stream = stdin;
if (!__validfp(stream) || p == NULL)
{
errno = EINVAL;
return NULL;
}
if (feof(stream) || ferror(stream))
return NULL;
while ((c = getchar()) != EOF)
if (c == '\n')
break;
else
*p++ = c;
*p = '\0';
/* Return null if we had an error, or if we got EOF
before writing any characters. */
if (ferror (stream) || (feof (stream) && p == s))
return NULL;
return s;
}