GETPASS(3) OpenBSD Programmer's Manual GETPASS(3)NAMEgetpass - get a password
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, 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
Upon successful completion, getpass() returns a pointer to a NUL-
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
/dev/tty
ERRORS
[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 ALSOcrypt(3), readpassphrase(3)STANDARDS
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
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.
OpenBSD 4.9 May 31, 2007 OpenBSD 4.9
