Re: Directory Recursion

[rob_au]

An interesting comment which I thought I might make is the fact that recent versions of File::Find, well at least that shipped with Perl 5.6.1, no longer use recursion (in the truest sense of the term) in order to generate a list of files. By recursion in the truest sense of the term, I refer to a single block of re-entrant code that is called for each new iteration through a directory - Instead, newer versions of File::Find make use of a stack method (search newer File::Find code for @Stack within the _find_dir subroutine) which allows for the processing of directories either by depth first or by breadth first, depending on where you expect files to reside.

A comparison of the File::Find code between versions 5.005.03 and 5.6.1 highlights a number of differences between recursion and stack processing which may be interesting to some.

 

perl -e 's&&[e-mail]&&&split/[@.]/&&s&.com.&_&&&print'

[merlyn]

Heh. That reminds me that I have a column that also does that. Directory "recursion" without recursion.

-- Randal L. Schwartz, Perl hacker

[Haloric]

I'm a few years late to the party - but you are iterating over an array that you are extending, (@files) not sure what the party line is on this, but it caused me grief. Create a temporary array, then append the two together at the end. Then throw it all away and use File::Find.

[choroba]

You replied to a wrong node. merlyn does not iterate over an array, he runs while (@array), which is correct.