blob: 575959354e2b5580646f88bf83bf586146a9201d [file] [log] [blame]
/* Copyright (C) 1992-2014 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 Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 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
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with the GNU C Library; if not, see
<>. */
#include <stdio.h>
#include <stdio_ext.h>
#include <string.h> /* For string function builtin redirect. */
#include <termios.h>
#include <unistd.h>
#include <wchar.h>
#define flockfile(s) _IO_flockfile (s)
#define funlockfile(s) _IO_funlockfile (s)
#include <bits/libc-lock.h>
/* It is desirable to use this bit on systems that have it.
The only bit of terminal state we want to twiddle is echoing, which is
done in software; there is no need to change the state of the terminal
hardware. */
#ifndef TCSASOFT
#define TCSASOFT 0
static void
call_fclose (void *arg)
if (arg != NULL)
fclose (arg);
char *
getpass (prompt)
const char *prompt;
FILE *in, *out;
struct termios s, t;
int tty_changed;
static char *buf;
static size_t bufsize;
ssize_t nread;
/* Try to write to and read from the terminal if we can.
If we can't open the terminal, use stderr and stdin. */
in = fopen ("/dev/tty", "w+ce");
if (in == NULL)
in = stdin;
out = stderr;
/* We do the locking ourselves. */
__fsetlocking (in, FSETLOCKING_BYCALLER);
out = in;
/* Make sure the stream we opened is closed even if the thread is
canceled. */
__libc_cleanup_push (call_fclose, in == out ? in : NULL);
flockfile (out);
/* Turn echoing off if it is on now. */
if (__tcgetattr (fileno (in), &t) == 0)
/* Save the old one. */
s = t;
/* Tricky, tricky. */
t.c_lflag &= ~(ECHO|ISIG);
tty_changed = (tcsetattr (fileno (in), TCSAFLUSH|TCSASOFT, &t) == 0);
tty_changed = 0;
/* Write the prompt. */
__fxprintf (out, "%s", prompt);
fflush_unlocked (out);
/* Read the password. */
nread = __getline (&buf, &bufsize, in);
if (buf != NULL)
if (nread < 0)
buf[0] = '\0';
else if (buf[nread - 1] == '\n')
/* Remove the newline. */
buf[nread - 1] = '\0';
if (tty_changed)
/* Write the newline that was not echoed. */
__fxprintf (out, "\n");
/* Restore the original setting. */
if (tty_changed)
(void) tcsetattr (fileno (in), TCSAFLUSH|TCSASOFT, &s);
funlockfile (out);
__libc_cleanup_pop (0);
if (in != stdin)
/* We opened the terminal; now close it. */
fclose (in);
return buf;