Programming Perl, 4th Edition

getgrent

getgrent
setgrent
endgrent

These routines iterate through your /etc/group file (or maybe someone else’s /etc/group file, if it’s coming from a server somewhere). The return value from getgrent in list context is:

#  0      1        2     3
($name, $passwd, $gid, $members) = getgrent();

where $members contains a space-separated list of the login names of the members of the group. To set up a hash for translating group names to GIDs, say this:

while (($name, $passwd, $gid) = getgrent()) {
    $gid{$name} = $gid;
}

In scalar context, getgrent returns only the group name. The standard User::grent module supports a by-name interface to this function. See getgrent(3).