endusershell
(3)get permitted user shells
#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)
LIBRARY
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.