NAME

getpass — get a password

LIBRARY

Standard C Library (libc, -lc)

SYNOPSIS

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

char *
getpass(const char *prompt);

DESCRIPTION

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) characters in length. Any additional characters and the terminating newline character are discarded.

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

RETURN VALUES

getpass() returns a pointer to the null terminated password.

FILES

/dev/tty

SEE ALSO

crypt(3)

STANDARDS

The getpass() function appeared in Version 2 of the Single UNIX Specification, but it was already marked as legacy. The function was removed in the IEEE Std 1003.1-2001 (“POSIX.1”) standard.

HISTORY

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

BUGS

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.

SECURITY CONSIDERATIONS

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