getusershell, setusershell, endusershell - 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)
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.
The
getusershell() function returns NULL on end-of-file.
/etc/shells
For an explanation of the terms used in this section, see
attributes(7).
Interface |
Attribute |
Value |
getusershell (), setusershell (), endusershell () |
Thread safety |
MT-Unsafe |
4.3BSD.
shells(5)