manual/examples/mygetpass.c

   1 /* Reading passphrases manually.
   2    Copyright (C) 1991-2024 Free Software Foundation, Inc.
   3
   4    This program is free software; you can redistribute it and/or
   5    modify it under the terms of the GNU General Public License
   6    as published by the Free Software Foundation; either version 2
   7    of the License, or (at your option) 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
  15    along with this program; if not, see <https://www.gnu.org/licenses/>.
  16 */
  17
  18 #include <termios.h>
  19 #include <stdio.h>
  20
  21 ssize_t
  22 my_getpass (char **lineptr, size_t *n, FILE *stream)
  23 {
  24   struct termios old, new;
  25   int nread;
  26
  27   /* Turn echoing off and fail if we can't.  */
  28   if (tcgetattr (fileno (stream), &old) != 0)
  29     return -1;
  30   new = old;
  31   new.c_lflag &= ~ECHO;
  32   if (tcsetattr (fileno (stream), TCSAFLUSH, &new) != 0)
  33     return -1;
  34
  35   /* Read the passphrase  */
  36   nread = getline (lineptr, n, stream);
  37
  38   /* Restore terminal.  */
  39   (void) tcsetattr (fileno (stream), TCSAFLUSH, &old);
  40
  41   return nread;
  42 }