NAME    [Toc]    [Back]

     getpass - get a password

SYNOPSIS    [Toc]    [Back]

     #include <pwd.h>
     #include <unistd.h>

     char *
     getpass(const char *prompt);

DESCRIPTION    [Toc]    [Back]

     The getpass() function displays a prompt to, and reads in  a
password
     from,  /dev/tty.   If this file is not accessible, getpass()
displays the
     prompt on the standard error output and reads from the standard input.

     The  password  may be up to _PASSWORD_LEN (currently 128, as
defined in the
     <pwd.h> include file) characters in length.  Any  additional
characters
     and the terminating newline character are discarded.

     getpass()  turns  off  character  echoing  while reading the
password.

     The calling process should zero the password as soon as possible to avoid
     leaving  the cleartext password visible in the process's address space.

RETURN VALUES    [Toc]    [Back]

     Upon successful completion, getpass() returns a pointer to a
null-terminated
 string of at most _PASSWORD_LEN characters.  If an error is encountered,
 the terminal state is restored and a null pointer  is
returned.

FILES    [Toc]    [Back]

     /dev/tty

ERRORS    [Toc]    [Back]

     [EINTR]        The  getpass()  function was interrupted by a
signal.

     [EIO]         The process is a member of a  background  process attempting
                   to  read  from  its  controlling terminal, the
process is ignoring
 or blocking the SIGTTIN signal  or  the
process group
                   is orphaned.

     [EMFILE]       The process has already reached its limit for
open file descriptors.


     [ENFILE]      The system file table is full.

SEE ALSO    [Toc]    [Back]

     crypt(3), readpassphrase(3)

STANDARDS    [Toc]    [Back]

     Historically, BSD versions  of  getpass()  have  accepted  a
password on the
     standard input if /dev/tty is unavailable.  This contradicts
X/Open
     Portability Guide Issue 4.2 (``XPG4.2'') but the OpenBSD implementation
     is conformant in all other respects.

HISTORY    [Toc]    [Back]

     A getpass() function appeared in Version 7 AT&T UNIX.

BUGS    [Toc]    [Back]

     The  getpass()  function  leaves  its  result in an internal
static object and
     returns a pointer  to  that  object.   Subsequent  calls  to
getpass() will
     modify the same object.

OpenBSD      3.6                         December     7,     2001