system does a fork and wait. But if you want to completely disassociate the system call from the parent process (meaning spawn the system call and then just move on, letting it do its thing alone without reporting back), you probably need to read Complete Disassociation of Child from Parent, in perlipc for an example of one way.

My guess: it'll be a lot easier to offer a good explanation if you show us your code.

If I understand what you wrote as you wrote it (intended?), your description doesn't match the way system works -- c.f. perldoc -f system:

system LIST
system PROGRAM LIST
       Does exactly the same thing as "exec LIST", except that a fork
       is done first, and the parent process waits for the child
       process to exit. ....

I agree, this is probably a "faux" problem

If you use system to open a program, i.e:

`gimp`;
print "gimp was closed\n";
print "... lots and lots of commands next";
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the script is stopped until the first line is finished, so the second, third etc lines, are "frozen" and never run until you close manually this gimp session.

 delete a folder which is created by this program after it gets closed by the user

It depends on your specific case, you could need to add another system line below doing the cleanup, a rmdir $dir line, or nothing

Sorry I didn't show any code. Is just a few lines long so I didn't think it was necessary. Example: system ("vp -e " . $ENV{'VREL'}); rm /home/$ENV{'verl'}; the problem is my program is dying when the user closes my vp program. I never get to the remove directory. I tried printing for debugging purposes also but my program is dying on that line.

The user's program is probably sending a SIGCHLD signal to your perl program which is killing it.    You probably need to ignore this signal.

How do I go about doing that ?

perldoc perlipc

       You may also choose to assign the strings 'IGNORE' or 'DEFAULT'
+ as the
       handler, in which case Perl will try to discard the signal or d
+o the default
       thing.

       On most Unix platforms, the "CHLD" (sometimes also known as "CL
+D") signal
       has special behavior with respect to a value of 'IGNORE'.  Sett
+ing
       $SIG{CHLD} to 'IGNORE' on such a platform has the effect of not
+ creating
       zombie processes when the parent process fails to "wait()" on i
+ts child
       processes (i.e. child processes are automatically reaped).  Cal
+ling
       "wait()" with $SIG{CHLD} set to 'IGNORE' usually returns "-1" o
+n such platforms.
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Ask Google... http://www.schwer.us/journal/2008/02/06/perl-sigchld-ignore-system-and-you/