Re: Help Explain Behavior

[BrowserUk]

in reply to Help Explain Behavior

Its a little more surprising than that even. Not only is the script still in memory and still running after you unlink it.

It is still on the disk also ... until the script exits ... at which point it automagically vanishes:

C:\test>copy con surprise.pl
#! perl -slw
use strict;

unlink $0;

print "still here";

print for glob $0;

print "Still there also";
^Z
        1 file(s) copied.

C:\test>surprise.pl
still here
C:\test\surprise.pl
Still there also

C:\test>dir surprise.pl
 Directory of C:\test
File Not Found

C:\test>

[Joe_]

Now that seems really strange to me. I understand that the whole script was already loaded into memory by the time the unlink happens; but shouldn't the file vanish after the unlink?

[BrowserUk]

When Perl loads the script, it retains an open filehandle to the source. The filesystem won't allow the file to be deleted until all open filehandles are closed.

So until the script ends, the source file is in a "marked for deletion" state.

[Joe_]

Thanks, I get it now.