A word on style:

$SYS_TYPE=1;
...
if ($SYS_TYPE == 1) {
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Don't do this. It just makes your code hard to read (and to maintain) - this is Perl not C.

So rather:

$sys_type = "AIX";
...
if ($sys_type eq "AIX") {
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All-caps are usually used for constants, not for normal variables.

And when an open fails $! contains the error-message from the OS (which is very useful), so rather than

open (DF, $FILE) || die "Can't Open File: $FILE\n";
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do it like this:

open my $df, "<", $file or die "Can't Open File: $file: $!\n
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