getpass — get a password
||const char *prompt
This function is obsolete. Do not use it. If you want to
read input without terminal echoing enabled, see the
description of the
ECHO flag in
getpass() function opens
/dev/tty (the controlling
terminal of the process), outputs the string
prompt, turns off echoing,
reads one line (the "password"), restores the terminal state
returns a pointer to a static buffer containing (the first
PASS_MAX 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,
errno is set appropriately, and NULL is
For an explanation of the terms used in this section, see attributes(7).
||Thread safety||MT-Unsafe term|
In the GNU C library implementation, if
/dev/tty cannot be opened, the prompt is
stderr 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
PASS_MAX must be defined in
in case it is smaller than 8, and can in any case be obtained
However, POSIX.2 withdraws the constants
_SC_PASS_MAX, and the function
getpass(). The glibc version accepts
_SC_PASS_MAX and returns
BUFSIZ (e.g., 8192).
The calling process should zero the password as soon as possible to avoid leaving the cleartext password visible in the process's address space.
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Copyright (c) 2000 Andries Brouwer (aebcwi.nl)
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