How many places do you see '-d'? How many places do you see '_'? '-d' stands for directory. '_' stands for ??? -d is the same as the unix file test, '_' is the same as ???.

It might be easy for you to remember things like this, bit it isn't for me. I guarantee you, in a week if you showed me -d(_) I'll have to look it up. And who wants to do that?

Where is this code running? Is the performance that important? Is -d $filename so much slower?

--Pileofrogs

-d $FILE stands for "test to see if $FILE is a directory";

_ stands for "the topic (of the current conversation)"^*;

so, -d _ means "test to see if the last tested file is a directory";

^*:

$_ is the topic of the for, will be used by default by regexen and a lot of functions
@_ is the collection of topics for a function (the arguments!)
_ is the topic for file tests.

[]s, HTH, Massa (κς,πμ,πλ)

How many places do you see '-d'?

None.

How many places do you see '_'?

It should be used just about everywhere -d is used.

-d is the same as the unix file test, '_' is the same as ???.

I guess you'll be disappointed when you try to use _ with test.

A google code search for '" -d " lang:perl' produces 108,000 results while a search for '"(_)" lang:perl' produces 6,000.

I'll grant you, some of those -d results are spurious, someone documenting a '-d' command line switch and so on.

Let's try and wrap this up. Do you agree with the statement, "-d $filename" is clearer than "-d (_)"? I'll agree that "-d (_)" is better for performance than "-d $filename". I'll even agree that my first post was stupid. OK?