1: /* Copyright (C) 1992-1999,2001,2003,2004,2005 Free Software Foundation, Inc.
    2:    This file is part of the GNU C Library.
    3: 
    4:    The GNU C Library is free software; you can redistribute it and/or
    5:    modify it under the terms of the GNU Lesser General Public
    6:    License as published by the Free Software Foundation; either
    7:    version 2.1 of the License, or (at your option) any later version.
    8: 
    9:    The GNU C Library 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 GNU
   12:    Lesser General Public License for more details.
   13: 
   14:    You should have received a copy of the GNU Lesser General Public
   15:    License along with the GNU C Library; if not, write to the Free
   16:    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
   17:    02111-1307 USA.  */
   18: 
   19: #include <stdio.h>
   20: #include <stdio_ext.h>
   21: #include <string.h>             /* For string function builtin redirect.  */
   22: #include <termios.h>
   23: #include <unistd.h>
   24: 
   25: #include <wchar.h>
   26: #define flockfile(s) _IO_flockfile (s)
   27: #define funlockfile(s) _IO_funlockfile (s)
   28: #include <bits/libc-lock.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: static void
   40: call_fclose (void *arg)
   41: {
   42:   if (arg != NULL)
   43:     fclose (arg);
   44: }
   45: 
   46: char *
   47: getpass (prompt)
   48:      const char *prompt;
   49: {
   50:   FILE *in, *out;
   51:   struct termios s, t;
   52:   int tty_changed;
   53:   static char *buf;
   54:   static size_t bufsize;
   55:   ssize_t nread;
   56: 
   57:   /* Try to write to and read from the terminal if we can.
   58:      If we can't open the terminal, use stderr and stdin.  */
   59: 
   60:   in = fopen ("/dev/tty", "w+c");
   61:   if (in == NULL)
   62:     {
   63:       in = stdin;
   64:       out = stderr;
   65:     }
   66:   else
   67:     {
   68:       /* We do the locking ourselves.  */
   69:       __fsetlocking (in, FSETLOCKING_BYCALLER);
   70: 
   71:       out = in;
   72:     }
   73: 
   74:   /* Make sure the stream we opened is closed even if the thread is
   75:      canceled.  */
   76:   __libc_cleanup_push (call_fclose, in == out ? in : NULL);
   77: 
   78:   flockfile (out);
   79: 
   80:   /* Turn echoing off if it is on now.  */
   81: 
   82:   if (__tcgetattr (fileno (in), &t) == 0)
   83:     {
   84:       /* Save the old one. */
   85:       s = t;
   86:       /* Tricky, tricky. */
   87:       t.c_lflag &= ~(ECHO|ISIG);
   88:       tty_changed = (tcsetattr (fileno (in), TCSAFLUSH|TCSASOFT, &t) == 0);
   89:     }
   90:   else
   91:     tty_changed = 0;
   92: 
   93:   /* Write the prompt.  */
   94:   __fxprintf (out, "%s", prompt);
   95:   fflush_unlocked (out);
   96: 
   97:   /* Read the password.  */
   98:   nread = __getline (&buf, &bufsize, in);
   99:   if (buf != NULL)
  100:     {
  101:       if (nread < 0)
  102:         buf[0] = '\0';
  103:       else if (buf[nread - 1] == '\n')
  104:         {
  105:           /* Remove the newline.  */
  106:           buf[nread - 1] = '\0';
  107:           if (tty_changed)
  108:             /* Write the newline that was not echoed.  */
  109:             __fxprintf (out, "\n");
  110:         }
  111:     }
  112: 
  113:   /* Restore the original setting.  */
  114:   if (tty_changed)
  115:     (void) tcsetattr (fileno (in), TCSAFLUSH|TCSASOFT, &s);
  116: 
  117:   funlockfile (out);
  118: 
  119:   __libc_cleanup_pop (0);
  120: 
  121:   if (in != stdin)
  122:     /* We opened the terminal; now close it.  */
  123:     fclose (in);
  124: 
  125:   return buf;
  126: }