1/* Copyright (C) 1992,93,94,95,96,97,98,99,2000, 2001 Free Software Foundation, Inc.
2   This file is part of the GNU C Library.
3
4   This program is free software; you can redistribute it and/or modify
5   it under the terms of the GNU General Public License as published by
6   the Free Software Foundation; either version 2, or (at your option)
7   any later version.
8
9   This program is distributed in the hope that it will be useful,
10   but WITHOUT ANY WARRANTY; without even the implied warranty of
11   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
12   GNU General Public License for more details.
13
14   You should have received a copy of the GNU General Public License along
15   with this program; if not, write to the Free Software Foundation,
16   Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.  */
17
18#if HAVE_CONFIG_H
19# include <config.h>
20#endif
21
22#include <stdio.h>
23#ifndef SEEK_CUR
24#define SEEK_CUR 1
25#endif
26#include <termios.h>
27#include <unistd.h>
28#include "getline.h"
29
30/* It is desirable to use this bit on systems that have it.
31   The only bit of terminal state we want to twiddle is echoing, which is
32   done in software; there is no need to change the state of the terminal
33   hardware.  */
34
35#ifndef TCSASOFT
36# define TCSASOFT 0
37#endif
38
39char *
40#if __STDC__
41getpass (const char *prompt)
42#else
43getpass (prompt)
44     const char *prompt;
45#endif
46{
47  FILE *in, *out;
48  struct termios s, t;
49  int tty_changed;
50  static char *buf;
51  static size_t bufsize;
52  ssize_t nread;
53
54  /* Try to write to and read from the terminal if we can.
55     If we can't open the terminal, use stderr and stdin.  */
56
57  in = fopen ("/dev/tty", "w+");
58  if (in == NULL)
59    {
60      in = stdin;
61      out = stderr;
62    }
63  else
64    out = in;
65
66  /* Turn echoing off if it is on now.  */
67
68  if (tcgetattr (fileno (in), &t) == 0)
69    {
70      /* Save the old one. */
71      s = t;
72      /* Tricky, tricky. */
73      t.c_lflag &= ~(ECHO|ISIG);
74      tty_changed = (tcsetattr (fileno (in), TCSAFLUSH|TCSASOFT, &t) == 0);
75    }
76  else
77    tty_changed = 0;
78
79  /* Write the prompt.  */
80  fputs (prompt, out);
81  fflush (out);
82
83  /* Read the password.  */
84  nread = getline (&buf, &bufsize, in);
85  if (buf != NULL)
86    {
87      if (nread < 0)
88	buf[0] = '\0';
89      else if (buf[nread - 1] == '\n')
90	{
91	  /* Remove the newline.  */
92	  buf[nread - 1] = '\0';
93	  if (tty_changed)
94	    {
95	      /* Write the newline that was not echoed.  */
96	      if (out == in) fseek (out, 0, SEEK_CUR);
97	      putc ('\n', out);
98	    }
99	}
100    }
101
102  /* Restore the original setting.  */
103  if (tty_changed)
104    (void) tcsetattr (fileno (in), TCSAFLUSH|TCSASOFT, &s);
105
106  if (in != stdin)
107    /* We opened the terminal; now close it.  */
108    fclose (in);
109
110  return buf;
111}
112