If the intention is to read the output file back into your program once tar is finished, you could bypass the filesystem by using a piped-open:

(See the docs for perlfuncopen and perlopentut)

# ..................v  
open TAR, "tar .... |" or die ...;
while( <TAR> {
    ## do stuff with the tar output
}
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## do stuff with the tar output could be as simple as print FILE $_;.

See also IO::Pipe.