You said that you want to work on subfolders. The 
next if -f $_;

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checks if the current directory entry (contained in $_) is a regular file (as opposed to directories or folders in MS parlance), and, if it is, goes directly to the next directory entry in the list. This way, the script will only work on subdirectories.

Update: as correctly pointed out below by Happy-the-monk, the code above will filter out only plain files (I used the words "regular files" to mean that). So that it is not completely accurate to write, as I did above, that the script will only work on subdirectories, since there can be other entities than just plain files and subdirectories. And it would be better to identify real directories with something like next unless -d $_;. Thank you, Happy-the-monk, for the added accuracy.

Je suis Charlie.

In reply to Re^3: How to get sub-folder names using perl? by Laurent_R
in thread How to get sub-folder names using perl? by erhan

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