getegid() -- System Call (libc)

Get effective group identifier
#include <unistd.h>
getegid()

Every process  has two different  versions of its  group identifier, called
the real  group identifier and  the effective group  identifier.  The group
identifiers  determine   eligibility  to   access  files  and   use  system
privileges.  Normally, these two identifiers are identical.  However, for a
set group  identifier load module (see exec), the  real group identifier is
that of  the group's current group, whereas  the effective group identifier
is that of the load  module owner.  This distinction allows system programs
to use files which are protected from groups that invoke the program.

getegid() returns the effective group identifier.

See Also

access,
exec,
geteuid(),
getgid(),
getuid(),
libc,
login,
setuid(),
unistd.h
POSIX Standard, §4.2.1

© 2012 by Stephen A. Ness