Section: Linux Programmer's Manual (3)
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getpass - get a password
char *getpass(const char *prompt);
Feature Test Macro Requirements for glibc (see
- Since glibc 2.2.2:
_XOPEN_SOURCE && ! (_POSIX_C_SOURCE >= 200112L)
|| /* Glibc since 2.19: */ _DEFAULT_SOURCE
|| /* Glibc versions <= 2.19: */ _BSD_SOURCE
- Before glibc 2.2.2:
This function is obsolete.
Do not use it.
If you want to read input without terminal echoing enabled,
see the description of the
(the controlling terminal of the process), outputs the string
turns off echoing, reads one line (the "password"),
restores the terminal state and closes
returns a pointer to a static buffer containing (the first
bytes of) the password without the trailing
newline, terminated by a null byte ('\0').
This buffer may be overwritten by a following call.
On error, the terminal state is restored,
is set appropriately, and NULL is returned.
The function may fail if
The process does not have a controlling terminal.
For an explanation of the terms used in this section, see
||Thread safety||MT-Unsafe term|
Present in SUSv2, but marked LEGACY.
Removed in POSIX.1-2001.
In the GNU C library implementation, if
cannot be opened, the prompt is written to
and the password is read from
There is no limit on the length of the password.
Line editing is not disabled.
According to SUSv2, the value of
must be defined in
in case it is smaller than 8, and can in any case be obtained using
However, POSIX.2 withdraws the constants
and the function
The glibc version accepts
The calling process should zero the password as soon as possible to avoid
leaving the cleartext password visible in the process's address space.
This page is part of release 4.16 of the Linux
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