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perlrenamebatch-rename

Perl's rename - how to append a counter?

There's a nice renaming utility, which comes with Perl's installation. How one would append a counter in the Perl regexp? This is a relevant question e.g. for a problem of numbering files in the current directory:

rename 's/^/<here I'd like to have a number of a file being processed>/g' *

For example how would one rename:

fileA
fileB
fileC

to

1 - fileA
2 - fileB
3 - fileC

Edit:

I've added the counter feature ($c variable) - see here. It works fine - but when I try to specify the counter format:

rename_c.pl -c 5.2f 's/^/$c - /' *

it says:

 Useless use of concatenation (.) or string in void context at line 120.

and it doesn't really use the format I told it to use. This must be some simple syntax mistake in a line number 120. Can You please take a look?

Solution

  • The line of code in question is:

    $c = sprintf(eval("%" . "$form", $cNumber));

    You don't want the eval there; you can simply create the format as a string:

    $c = sprintf("%$form", $cNumber));

    The string (first argument) ends up containing the format requested, and sprintf() formats $cNumber using that.