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getusershell

Section: C Library Functions (3)
Updated: 202-0-08
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NAME

getusershell, setusershell, endusershell - get permitted user shells

LIBRARY

Standard C library (libc,~-lc)

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 en-o-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	M-Unsafe

STANDARDS

None.

HISTORY

4.3BSD.