204 lines
5.3 KiB
Groff
204 lines
5.3 KiB
Groff
.\" Copyright (c) 1989, 1991, 1993
|
|
.\" The Regents of the University of California. All rights reserved.
|
|
.\"
|
|
.\" Redistribution and use in source and binary forms, with or without
|
|
.\" modification, are permitted provided that the following conditions
|
|
.\" are met:
|
|
.\" 1. Redistributions of source code must retain the above copyright
|
|
.\" notice, this list of conditions and the following disclaimer.
|
|
.\" 2. Redistributions in binary form must reproduce the above copyright
|
|
.\" notice, this list of conditions and the following disclaimer in the
|
|
.\" documentation and/or other materials provided with the distribution.
|
|
.\" 3. All advertising materials mentioning features or use of this software
|
|
.\" must display the following acknowledgement:
|
|
.\" This product includes software developed by the University of
|
|
.\" California, Berkeley and its contributors.
|
|
.\" 4. Neither the name of the University nor the names of its contributors
|
|
.\" may be used to endorse or promote products derived from this software
|
|
.\" without specific prior written permission.
|
|
.\"
|
|
.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
|
|
.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
|
|
.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
|
|
.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
|
|
.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
|
|
.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
|
|
.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
|
|
.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
|
|
.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
|
|
.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
|
|
.\" SUCH DAMAGE.
|
|
.\"
|
|
.\" From: @(#)getgrent.3 8.2 (Berkeley) 4/19/94
|
|
.\" $FreeBSD$
|
|
.\"
|
|
.Dd September 29, 1994
|
|
.Dt GETGRENT 3
|
|
.Os
|
|
.Sh NAME
|
|
.Nm getgrent ,
|
|
.Nm getgrnam ,
|
|
.Nm getgrgid ,
|
|
.Nm setgroupent ,
|
|
.\" .Nm setgrfile ,
|
|
.Nm setgrent ,
|
|
.Nm endgrent
|
|
.Nd group database operations
|
|
.Sh LIBRARY
|
|
.Lb libc
|
|
.Sh SYNOPSIS
|
|
.In sys/types.h
|
|
.In grp.h
|
|
.Ft struct group *
|
|
.Fn getgrent void
|
|
.Ft struct group *
|
|
.Fn getgrnam "const char *name"
|
|
.Ft struct group *
|
|
.Fn getgrgid "gid_t gid"
|
|
.Ft int
|
|
.Fn setgroupent "int stayopen"
|
|
.\" .Ft void
|
|
.\" .Fn setgrfile "const char *name"
|
|
.Ft int
|
|
.Fn setgrent void
|
|
.Ft void
|
|
.Fn endgrent void
|
|
.Sh DESCRIPTION
|
|
These functions operate on the group database file
|
|
.Pa /etc/group
|
|
which is described
|
|
in
|
|
.Xr group 5 .
|
|
Each line of the database is defined by the structure
|
|
.Ar group
|
|
found in the include
|
|
file
|
|
.Aq Pa grp.h :
|
|
.Bd -literal -offset indent
|
|
struct group {
|
|
char *gr_name; /* group name */
|
|
char *gr_passwd; /* group password */
|
|
gid_t gr_gid; /* group id */
|
|
char **gr_mem; /* group members */
|
|
};
|
|
.Ed
|
|
.Pp
|
|
The functions
|
|
.Fn getgrnam
|
|
and
|
|
.Fn getgrgid
|
|
search the group database for the given group name pointed to by
|
|
.Ar name
|
|
or the group id pointed to by
|
|
.Ar gid ,
|
|
respectively, returning the first one encountered. Identical group
|
|
names or group gids may result in undefined behavior.
|
|
.Pp
|
|
The
|
|
.Fn getgrent
|
|
function
|
|
sequentially reads the group database and is intended for programs
|
|
that wish to step through the complete list of groups.
|
|
.Pp
|
|
All three routines will open the group file for reading, if necessary.
|
|
.Pp
|
|
The
|
|
.Fn setgroupent
|
|
function
|
|
opens the file, or rewinds it if it is already open. If
|
|
.Fa stayopen
|
|
is non-zero, file descriptors are left open, significantly speeding
|
|
functions subsequent calls. This functionality is unnecessary for
|
|
.Fn getgrent
|
|
as it doesn't close its file descriptors by default. It should also
|
|
be noted that it is dangerous for long-running programs to use this
|
|
functionality as the group file may be updated.
|
|
.Pp
|
|
The
|
|
.Fn setgrent
|
|
function
|
|
is identical to
|
|
.Fn setgroupent
|
|
with an argument of zero.
|
|
.Pp
|
|
The
|
|
.Fn endgrent
|
|
function
|
|
closes any open files.
|
|
.Sh RETURN VALUES
|
|
The functions
|
|
.Fn getgrent ,
|
|
.Fn getgrnam ,
|
|
and
|
|
.Fn getgrgid ,
|
|
return a pointer to the group entry if successful; if end-of-file
|
|
is reached or an error occurs a null pointer is returned.
|
|
The functions
|
|
.Fn setgroupent
|
|
and
|
|
.Fn setgrent
|
|
return the value 1 if successful, otherwise the value
|
|
0 is returned.
|
|
The functions
|
|
.Fn endgrent
|
|
and
|
|
.Fn setgrfile
|
|
have no return value.
|
|
.Sh FILES
|
|
.Bl -tag -width /etc/group -compact
|
|
.It Pa /etc/group
|
|
group database file
|
|
.El
|
|
.Sh SEE ALSO
|
|
.Xr getpwent 3 ,
|
|
.Xr group 5 ,
|
|
.Xr nsswitch.conf 5 ,
|
|
.Xr yp 8
|
|
.Sh HISTORY
|
|
The functions
|
|
.Fn endgrent ,
|
|
.Fn getgrent ,
|
|
.Fn getgrnam ,
|
|
.Fn getgrgid ,
|
|
and
|
|
.Fn setgrent
|
|
appeared in
|
|
.At v7 .
|
|
The functions
|
|
.Fn setgrfile
|
|
and
|
|
.Fn setgroupent
|
|
appeared in
|
|
.Bx 4.3 Reno .
|
|
.Sh COMPATIBILITY
|
|
The historic function
|
|
.Fn setgrfile ,
|
|
which allowed the specification of alternate password databases, has
|
|
been deprecated and is no longer available.
|
|
.Sh BUGS
|
|
The functions
|
|
.Fn getgrent ,
|
|
.Fn getgrnam ,
|
|
.Fn getgrgid ,
|
|
.Fn setgroupent
|
|
and
|
|
.Fn setgrent
|
|
leave their results in an internal static object and return
|
|
a pointer to that object.
|
|
Subsequent calls to
|
|
the same function
|
|
will modify the same object.
|
|
.Pp
|
|
The functions
|
|
.Fn getgrent ,
|
|
.Fn endgrent ,
|
|
.Fn setgroupent ,
|
|
and
|
|
.Fn setgrent
|
|
are fairly useless in a networked environment and should be
|
|
avoided, if possible.
|
|
.Fn getgrent
|
|
makes no attempt to suppress duplicate information if multiple
|
|
sources are specified in
|
|
.Xr nsswitch.conf 5 .
|