I couldn't understand how your code relates to your description, except for this part:

if I change one part of the name (%03d), then I get errors about the file not being clobbered.

That would be happening because you are trying to open file names for output when the files already exist in your current working directory -- your posted code specifically dies when this is the case. You could just create a new directory and run the script there (with adjustments to the input file name).

For all your concerns about renaming files, I'm wondering why you don't show any use of the rename function. If you have hundreds of files to rename, you just need a list of the existing file names, and a corresponding list of the intended file names (or a method for deriving intended names from existing names, e.g. by adding and/or replacing something). Then just loop over the list: 

for my $old ( @existing_names ) {
    my $new = $old . ".foobar";
    rename $old, $new or warn "rename failed for $old -> $new\n";
}

[download]

In reply to Re: Renaming Multiple Files with Different Names by graff
in thread Renaming Multiple Files with Different Names by Feral_Akodon

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