checkcreate-tmp-owner-dir

#!/usr/bin/perl -w

# Thu Aug 28 00:02:51 CEST 2008
(my $email='XXX%YYY,ch')=~ tr/%,/@./;

use strict;

$0=~ /(.*?)([^\/]+)\z/s or die "?";
my ($mydir, $myname)=($1,$2);
sub usage {
    print STDERR map{"$_\n"} @_ if @_;
    print "$myname

  Create /tmp/\$USER if it doesn't exist already (checking whether
  \$USER matches uid in getpwent data), or check whether it's owned by
  the current user and it's got private permissions.
  Return with success if everything's fine (for cd
  to enter and use the dir).

  (Christian Jaeger <$email>)
";
exit (@_ ? 1 : 0);
}

use Getopt::Long;
our $verbose=0;
GetOptions("verbose"=> \$verbose,
	   "help"=> sub{usage},
	   ) or exit 1;
usage if @ARGV;

sub Die {
    die "$myname: @_\n";
}

our $uid= $>; ##correct right?
our $usernam= do {
    my $nam= $ENV{USER};
    defined (my $expected_uid= getpwnam $nam)
      or Die "couldn't look up user '$nam'";
    $expected_uid == $uid
      or Die "uid for user '$nam' doesn't match the current uid";
#    $nam=~ /
    $nam
};
our $tmp_owner_dir= "/tmp/$usernam";

use Chj::xperlfunc ':all';

if (my $s= Xlstat $tmp_owner_dir) {
    $s->uid == $uid
      or Die "item '$tmp_owner_dir' is not owned by you";
    # no need to check whether it's a symlink or dir, right? since if
    # it's a symlink, the followup check is "racy" anyway (hm in which
    # sense?) but anyway, cd will then fail, 'as easy as that', k?
    $s->permissions == 0700
      or Die "item '$tmp_owner_dir' does not have private permissions";
} else {
    xmkdir $tmp_owner_dir, 0700;
    # done.
}

#use Chj::ruse;
#use Chj::Backtrace; use Chj::repl; repl;