getusershell

Section: C Library Functions (3)
Updated: 2022-12-15
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NAME

getusershell, setusershell, endusershell - get permitted user shells  

LIBRARY

Standard C library (libc, -lc)  

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(): 

    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

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 NULL on end-of-file.  

FILES

/etc/shells  

ATTRIBUTES

For an explanation of the terms used in this section, see attributes(7).
InterfaceAttributeValue
getusershell(), setusershell(), endusershell() Thread safetyMT-Unsafe

 

STANDARDS

4.3BSD.  

SEE ALSO

shells(5)

 

Index

NAME
LIBRARY
SYNOPSIS
DESCRIPTION
RETURN VALUE
FILES
ATTRIBUTES
STANDARDS
SEE ALSO
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Time: 01:50:57 GMT, April 19, 2024