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
39 char *
40 #if __STDC__
getpass(const char * prompt)41 getpass (const char *prompt)
42 #else
43 getpass (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