man pages section 3: Basic Library Functions

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Updated: July 2014
 
 

getpass(3C)

Name

getpass, getpassphrase - read a string of characters without echo

Synopsis

#include <stdlib.h>

char *getpass(const char *prompt);
char *getpassphrase(const char *prompt);

XPG4, SUS, SUSv2

#include <unistd.h>

char *getpass(const char *prompt);

Description

The getpass() function opens the process's controlling terminal, writes to that device the null-terminated string prompt, disables echoing, reads a string of characters up to the next newline character or EOF, restores the terminal state and closes the terminal.

The getpassphrase() function is identical to getpass(), except that it reads and returns a string of up to 257 characters in length.

Return Values

Upon successful completion, getpass() returns a pointer to a null-terminated string of at most 9 bytes that were read from the terminal device. If an error is encountered, the terminal state is restored and a null pointer is returned.

Errors

The getpass() and getpassphrase() functions may fail if:

EINTR

The 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

OPEN_MAX file descriptors are currently open in the calling process.

ENFILE

The maximum allowable number of files is currently open in the system.

ENXIO

The process does not have a controlling terminal.

Usage

The return value points to static data whose content may be overwritten by each call.

Attributes

See attributes(5) for descriptions of the following attributes:

ATTRIBUTE TYPE
ATTRIBUTE VALUE
Interface Stability
getpass() is Standard.
MT-Level
Unsafe

See Also

attributes(5), standards(5)