GETUSERSHELL(3)

NAME
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
 | Thread safety | MT-Unsafe

CONFORMING TO
4.3BSD.

SEE ALSO
shells(5)

COLOPHON
This page is part of release 4.16 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/.