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in reply to Renaming all files in a directory

That may not work correctly, depending on what characters are in the file name:

$ ls -l total 0 -rw-r--r-- 1 john john 0 Feb 1 20:23 four -rw-r--r-- 1 john john 0 Feb 1 20:23 one -rw-r--r-- 1 john john 0 Feb 1 20:23 two ? three $ ls | perl -nle 'BEGIN { $counter = 0 }; $old = $_; $new = "caption" +. "$counter" . ".txt"; rename( $old, $new ); $counter++;' $ ls -l total 0 -rw-r--r-- 1 john john 0 Feb 1 20:23 caption0.txt -rw-r--r-- 1 john john 0 Feb 1 20:23 caption1.txt -rw-r--r-- 1 john john 0 Feb 1 20:23 two ? three

Better to use perl's built-in glob function:

$ ls -l total 0 -rw-r--r-- 1 john john 0 Feb 1 20:28 four -rw-r--r-- 1 john john 0 Feb 1 20:28 one -rw-r--r-- 1 john john 0 Feb 1 20:28 two ? three $ perl -e '$counter = 0; for ( <*> ) { $old = $_; $new = "caption" . " +$counter" . ".txt"; rename( $old, $new ); $counter++; }' $ ls -l total 0 -rw-r--r-- 1 john john 0 Feb 1 20:28 caption0.txt -rw-r--r-- 1 john john 0 Feb 1 20:28 caption1.txt -rw-r--r-- 1 john john 0 Feb 1 20:28 caption2.txt

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Re^2: Renaming all files in a directory
by Anonymous Monk on Feb 02, 2021 at 12:46 UTC
    Why needs the counter be inside a BEGIN block?
      In this example, perl is reading line by line, (perl -nle ...) and you want the counter to only be initialized (once) at the start of the script.