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(): _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 a NULL pointer on end-of-file.

FILES
       /etc/shells

CONFORMING TO
       4.3BSD.

SEE ALSO
       shells(5)

COLOPHON
       This page is part of release 3.23 of the Linux  man-pages  project.   A
       description  of  the project, and information about reporting bugs, can
       be found at http://www.kernel.org/doc/man-pages/.