xfree86 man page for getusershell

GETUSERSHELL(3) 					     Linux Programmer's Manual						   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     |
       +--------------------------------+---------------+-----------+
       |getusershell(), setusershell(), | Thread safety | MT-Unsafe |
       |endusershell()			|		|	    |
       +--------------------------------+---------------+-----------+
CONFORMING TO
       4.3BSD.

SEE ALSO
       shells(5)

COLOPHON
       This  page is part of release 4.15 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/.

GNU
								    2016-03-15							   GETUSERSHELL(3)