— get a
() 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
(currently 128, as defined in the
include file) characters in length. Any additional characters and the
terminating newline character are discarded.
() turns off character echoing while reading
The calling process should zero the password with
soon as possible to avoid leaving the cleartext password visible in the
process's address space.
Upon successful completion, getpass
() returns a
pointer to a NUL-terminated string of at most
characters. If an error is
encountered, the terminal state is restored and a null pointer is returned.
- The getpass() function was
interrupted by a signal.
- 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.
- The process has already reached its limit for open file
- The system file table is full.
() have accepted a password on the
standard input if /dev/tty
is unavailable. This
contradicts X/Open Portability Guide
Issue 4, Version 2 (“XPG4.2”)
implementation is conformant in all other
respects. Removed from IEEE Std 1003.1-2001
() function appeared in
Version 7 AT&T UNIX
() function leaves its result in an
internal static object and returns a pointer to that object. Subsequent calls
() will modify the same object.