#opens counter data file
open(COUNTERDAT,"./counter.dat");

#locks file, and if can't, goes back to READCOUNTER to try again
flock COUNTERDAT, 1 or next READCOUNTER;


##</code><code>##

#opens counter data file again
open(COUNTERDAT,">./counter.dat");

#locks file, and if can't, goes back to WRITECOUNTER
flock COUNTERDAT, 2 or next WRITECOUNTER;


##</code><code>##

open(COUNTERDAT,"./counter.dat");
flock COUNTERDAT, 1 or next READCOUNTER;