coec has asked for the wisdom of the Perl Monks concerning the following question:

Hi all

I have a Perl script that traverses a directory structure, processing files as it goes. The script needs to not leave the current filesystem, basicaly, equiv to adding -xdev to Unix find. I'm looking for a better way to do this.

Currently I'm doing equiv to `df . | awk '{print $1}'` and checking that the filesystem is the same. I was looking for a pure Perl solution and all I can think of is using "(stat $dir)[0]".

Are there better ways of doing this?

Thanks

CC

Replies are listed 'Best First'.
Re: Filesystem checking
by Zaxo (Archbishop) on Apr 30, 2004 at 07:05 UTC

    I think your (stat $dir)[0] idea is fine. Another possibility is to use the -l file test. That still calls stat, so it's probably not any improvement.

    You could evade all those stat calls by parsing mount points out of /etc/mtab or the system mount call, then matching paths. That seems messy and has possible inaccuracies, though.

    After Compline,
    Zaxo

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Re: Filesystem checking
by pelagic (Priest) on Apr 30, 2004 at 07:29 UTC
    Have you tried this?
    use File::Spec;
($volume,$directories,$file) = File::Spec->splitpath( $path );

    [download]
    I don't know the internal implementation of it but it might be worth a try.

    pelagic
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      I tried this on both AIX and Linux, $volume was '' on both. Worth a try, though...
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        I was sorta guessing ... but now I looked into the code:
        For VMS, W32, Mac and OS2 '$volume' means something like drive e.g. 'C:'
        as for Unix its not implemented at all and always returns ''

        pelagic
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Re: Filesystem checking
by eserte (Deacon) on Apr 30, 2004 at 08:58 UTC
    Using (stat $dir)[0] is fine. If you're using File::Find, then it may be worth to take a look at the output of find2perl -xdev.
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