Re^5: What does

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It's a question of Perl Culture by massa (Hermit) on Feb 04, 2009 at 11:12 UTC
`-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)	[reply] [d/l] [select]
Re^6: What does _ mean? by ikegami (Patriarch) on Feb 04, 2009 at 02:08 UTC
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`.	[reply] [d/l] [select]
Re^7: What does _ mean? by pileofrogs (Priest) on Feb 04, 2009 at 17:29 UTC
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?	[reply] [d/l] [select]
Re^8: What does _ mean? by ikegami (Patriarch) on Feb 04, 2009 at 18:02 UTC
Do you agree with the statement, "-d $filename" is clearer than "-d (_)"? No. The meaning of neither is ambiguous. You may not know what they do, but I don't see how you could possibly think they do something than what they do.	[reply]
Re^9: What does _ mean? by Argel (Prior) on Feb 04, 2009 at 20:46 UTC
Re^10: What does _ mean? by ikegami (Patriarch) on Feb 04, 2009 at 20:49 UTC
Some notes below your chosen depth have not been shown here
Re^9: What does _ mean? by pileofrogs (Priest) on Feb 04, 2009 at 19:15 UTC
Re^10: What does _ mean? by ikegami (Patriarch) on Feb 04, 2009 at 19:53 UTC
Re^8: What does _ mean? by massa (Hermit) on Feb 04, 2009 at 22:48 UTC
Your results are inconclusive, as `-d _` without the parentheses would be enough. Maybe if you pit the total of `-X $something` against the total of `-X _` plus `-X(_)` plus `-X (_)` etc you would have a better idea. Anyway, the point is moot because (IMHO!!) this: `if( -x $filename and -d _ )` [download] is better, cleaner, more concise, and clearer, than `if( -x $filename and -d $filename )` [download] because I am used to Perl and I know that anything that has `_` in it means *that thing we were just talking about*, i.e., the Topic. []s, HTH, Massa (κς,πμ,πλ)	[reply] [d/l] [select]