in reply to Re^2: List and identify directories
in thread List and identify directories

Any of the -X operators involve a call to stat(). You can use the cached result by doing if -f $_ and ! -l _ ie the '_' char accesses the (last) cached stat result. As for readdir vs glob I would expect them to be similar for speed. glob *is* different from readdir in one important way that can bite you if you don't expect it. With glob you will have the full/partial path you fed it in every result element. Sometimes this is very convenient as it saves adding the path, sometimes of course it is not. If it is convenient I use glob, if I just want the file/dir names without any path I use readdir.

cheers

tachyon

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Re^4: List and identify directories
by BrowserUk (Patriarch) on Jun 29, 2004 at 03:34 UTC
    As for readdir vs glob I would expect them to be similar for speed.

    I got caught by that assumption a while ago...but glob is still nicer. 

    P:\test>perl -MBenchmark=cmpthese -le" cmpthese( -1, {    
    glob=>q[
        @f=@d=();
        push @{ -d() ? \@d : \@f }, $_ for glob('*');
    ], 
    readdir=>q[ 
        @d=@f=();
        opendir D, '.'; 
        push @{ -d() ? \@d : \@f }, $_ while $_ = readdir D;
    ] 
});"

          Rate    glob readdir
glob    22.9/s      --    -48%
readdir 44.4/s     94%      --

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