The removal is completed and disk space released once your program closes.
I believe the removal is happening even earlier -- after the program has compiled, and the Perl interpreter has started executing it, but potentially long before the program completes.  Try this to see what I mean: 
#!/usr/bin/perl -w
                                                                      
+          
# Strict
use strict;
use warnings;
                                                                      
+          
# Main program
print "Check file before unlink\n"; sleep 1;   system("ls $0");
print "Unlinking the file $0\n";    sleep 1;   unlink $0;
print "Check file after unlink\n";  sleep 1;   system("ls $0");
                                                                      
+          
print "File should be now be gone from disk (but still in memory)\n";
print "Try ^Z and check it with 'ls $0' ... (come back with 'fg')\n";
sleep 10;
                                                                      
+          
print "I'm still here, but the original file is long gone.\n";

[download]
And when you run it: 
% chmod +x rmtest
% rmtest
Check file 'rmtest' before unlink
rmtest
Unlinking the file 'rmtest'
Check file 'rmtest' after unlink
ls: rmtest: No such file or directory
File should be now be gone from disk (but still in memory)
Try ^Z and check it with 'ls rmtest' ... (come back with 'fg')
 
Suspended
% ls rmtest
ls: rmtest: No such file or directory
% fg
rmtest
I'm still here, but the original file is long gone.
%

In reply to Re^2: Deleting a file after it runs? by liverpole
in thread Deleting a file after it runs? by Spidy

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