c.pl

#!/usr/local/bin/perl5
#
# Time-stamp: <1999-07-04 19:15:55 hirose31>
#
# flock() を使わなくても壊れないカウンタ
# つっても排他制御してるんだけどね。
#

BEGIN: { $|++; }

#$SIG{INT} = \&finish; # fixme ほかにもいろいろ

my $cfile    = 'n.dat';
my $cfiletmp = "$cfile.$$";

sub alarm_h {
  alarm 0;
  print "rest alarm and do next.";
  if ( glob("n.dat*") ) {
    open T, ">>$cfile"; close T;
  } else {
    exit 1;
  }
}

#$SIG{ALRM} = \&alarm_h;
#alarm 5;
while ( ! rename($cfile, $cfiletmp) ) {
#  rename $cfile, $cfiletmp and last;
#  glob("n.dat*") or die $!;
  print ".";
}
#alarm 0;

print "open.\n";
# here we go!
open R, "+<$cfiletmp" or die "$!";

#sleep 1;
seek R, 0, 0;
my $c = <R>;
chomp $c;
$c++;
print "$c\n";

#<STDIN>;
#sleep 1;
seek R, 0, 0;
print R $c;

close R or die "$!";

#<STDIN>;
#sleep 1;
&finish();

###

sub finish {
	#print "f\n";
	rename $cfiletmp, $cfile or die "$!";
	exit;
}

# vi: set ts=4 sw=4: