Linux manual pages Section 3  

Name

getusershell, setusershell, endusershell — get permitted user shells

Synopsis

        #include <unistd.h>
char *getusershell( void);  
 
void setusershell( void);  
 
void endusershell( void);  
 
[Note] Note
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 4.07 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/.


  Copyright 1993 David Metcalfe (davidprism.demon.co.uk)

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References consulted:
    Linux libc source code
    Lewine's _POSIX Programmer's Guide_ (O'Reilly & Associates, 1991)
    386BSD man pages
Modified Sat Jul 24 19:17:53 1993 by Rik Faith (faithcs.unc.edu)