getusershell(3) - Linux manual page (original) (raw)

getusershell(3) Library Functions Manual getusershell(3)

NAME top

   getusershell, setusershell, endusershell - get permitted user
   shells

LIBRARY top

   Standard C library (_libc_, _-lc_)

SYNOPSIS top

   **#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)

DESCRIPTION top

   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 top

   The **getusershell**() function returns NULL on end-of-file.

FILES top

   _/etc/shells_

ATTRIBUTES top

   For an explanation of the terms used in this section, see
   [attributes(7)](../man7/attributes.7.html).
   ┌────────────────────────────────────┬───────────────┬───────────┐
   │ **Interface** │ **Attribute** │ **Value** │
   ├────────────────────────────────────┼───────────────┼───────────┤
   │ **getusershell**(), **setusershell**(),    │ Thread safety │ MT-Unsafe │
   │ **endusershell**()                     │               │           │
   └────────────────────────────────────┴───────────────┴───────────┘

STANDARDS top

   None.

HISTORY top

   4.3BSD.

SEE ALSO top

   [shells(5)](../man5/shells.5.html)

COLOPHON top

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Linux man-pages 6.10 2024-07-23 getusershell(3)

Pages that refer to this page:shells(5)