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():
           _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

ATTRIBUTES

   Multithreading (see pthreads(7))
       The getusershell(), setusershell() and endusershell() functions are not thread-safe.

CONFORMING TO

       4.3BSD.

SEE ALSO

       shells(5)

COLOPHON

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       project,     and    information    about    reporting    bugs,    can    be    found    at
       http://www.kernel.org/doc/man-pages/.