getgid.2

来自「<B>Digital的Unix操作系统VAX 4.2源码</B>」· 2 代码 · 共 42 行

.\" SCCSID: @(#)getgid.2	2.1	3/10/87
.TH getgid 2
.SH Name
getgid, getegid \- get group identity
.SH Syntax
.nf
.B #include <sys/types.h>
.B #include <unistd.h>
.PP
.B gid = getgid()
.B gid_t gid;
.PP
.B egid = getegid()
.B gid_t egid;
.fi
.SH Description
.NXR "getgid system call"
.NXR "getegid system call"
.NXR "real group ID" "getting"
.NXR "effective group ID" "getting"
The
.PN getgid
system call returns the real group ID of the current process, and the
.PN getegid
call returns the effective group ID.
.PP
The real group ID is specified at login time.
.PP
The effective group ID is more transient and determines
additional access permission during execution of a
``set-group-ID'' process. The
.PN getgid
call is most useful with processes that are ``set-group-ID.''
.SH Environment
Differs from the System V definition in that
the return values are of type
.I int, 
instead of type 
.I unsigned short.
.SH See Also
getuid(2), setregid(2), setgid(3)