getusershell, setusershell, endusershell — get permitted user shells

Synopsis

#include <unistd.h>

char *getusershell(void);

void setusershell(void);

void endusershell(void);

Feature Test Macro Requirements for glibc (see feature_test_macros(7)):

getusershell(), setusershell(), endusershell():

    Since glibc 2.21:
        _DEFAULT_SOURCE
    In glibc 2.19 and 2.20:
        _DEFAULT_SOURCE || (_XOPEN_SOURCE && _XOPEN_SOURCE < 500)
    Up to and including glibc 2.19:
        _BSD_SOURCE || (_XOPEN_SOURCE && _XOPEN_SOURCE < 500)

Description

The getusershell() function returns the next line from the file /etc/shells, opening the file if necessary. The line should contain the pathname of a valid user shell. If /etc/shells does not exist or is unreadable, getusershell() behaves as if /bin/sh and /bin/csh were listed in the file.

The setusershell() function rewinds /etc/shells.

The endusershell() function closes /etc/shells.

Return Value

The getusershell() function returns NULL on end-of-file.

Files

/etc/shells

Attributes

For an explanation of the terms used in this section, see attributes(7).

Interface Attribute Value
getusershell(), setusershell(),
endusershell()
Thread safety MT-Unsafe

Conforming to

4.3BSD.

See Also

shells(5)

Colophon

This page is part of release 5.04 of the Linux man-pages project. A description of the project, information about reporting bugs, and the latest version of this page, can be found at https://www.kernel.org/doc/man-pages/.

Referenced By

ksu(1), shells(5).

The man pages endusershell(3) and setusershell(3) are aliases of getusershell(3).

2016-03-15 GNU Linux Programmer's Manual