shadow/libmisc/yesno.c
Samanta Navarro c0fc4d2122 libmisc/yesno.c: Fix regression
The getline function does not return a pointer but the amount of read
characters. The error return value to check for is -1.

Set buf to NULL to avoid dereference of an uninitialized stack value.

The getline function returns -1 if size argument is NULL. Always use
a valid pointer even if size is unimportant.

Signed-off-by: Samanta Navarro <ferivoz@riseup.net>
2023-04-28 11:22:48 -05:00

88 lines
1.4 KiB
C

/*
* SPDX-FileCopyrightText: 1992 - 1994, Julianne Frances Haugh
* SPDX-FileCopyrightText: 2007 - 2008, Nicolas François
* SPDX-FileCopyrightText: 2023, Alejandro Colomar <alx@kernel.org>
*
* SPDX-License-Identifier: BSD-3-Clause
*/
#include <config.h>
#ident "$Id$"
#include <stdbool.h>
#include <stdio.h>
#include <stdlib.h>
#include "prototypes.h"
/*
* Synopsis
* bool yes_or_no(bool read_only);
*
* Arguments
* read_only
* In read-only mode, all questions are answered "no". It
* will print "No" to stdout.
*
* Description
* After a yes/no question, this function gets the answer from the
* user.
*
* Calls to this function will normally be preceeded by a prompt on
* stdout, so we should fflush(3).
*
* Return value
* false "no"
* true "yes"
*
* See also
* rpmatch(3)
*/
#if !defined(HAVE_RPMATCH)
static int rpmatch(const char *response);
#endif
bool
yes_or_no(bool read_only)
{
bool ret;
char *buf;
size_t size;
if (read_only) {
puts(_("No"));
return false;
}
fflush(stdout);
buf = NULL;
ret = false;
size = 0;
if (getline(&buf, &size, stdin) != -1)
ret = rpmatch(buf) == 1;
free(buf);
return ret;
}
#if !defined(HAVE_RPMATCH)
static int
rpmatch(const char *response)
{
if (response[0] == 'y' || response[0] == 'Y')
return 1;
if (response[0] == 'n' || response[0] == 'n')
return 0;
return -1;
}
#endif