Testing a command line argument

mike65535 has asked for the wisdom of the Perl Monks concerning the following question:

Monk-dom,

I have some code that's wrapped with a test:

if( $ARGV[1] eq "ALL" )
[download]

I want to improve that test to be case-Insensitive and also to include the numeric '0'.

Like this

if ( $ARGV[1] eq (/^ALL|0)$/i) )
[download]

but it appears that's not a valid implementation (not sure what it does!)

Thanks for your help!

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Re: Testing a command line argument by toolic (Bishop) on Dec 10, 2015 at 17:35 UTC
Use the bind operator (=~) instead of eq for regular expressions, and the parens are in the wrong place: `if ( $ARGV[1] =~ /^(ALL\|0)$/i ) {` [download]	[reply] [d/l]
Re^2: Testing a command line argument by mike65535 (Novice) on Dec 10, 2015 at 17:58 UTC
Thanks for the "bind" tip. Sorry for the parens mistake (and the ensuing trouble it caused!) I have to use a separate computer to develop code on from the one on which I have Internet access so it's difficult to lift the code directly (without burning a CD, believe it or not). Thanks again.	[reply]
Re: Testing a command line argument by BillKSmith (Monsignor) on Dec 10, 2015 at 20:33 UTC
Fixing your operator as others have suggested will give you valid perl code. It still may not do exactly what you want. First note that `ARGV[1]` refers to the second argument, not the first. A regular expression treats the argument as a string. Your regex will match any string that begins with the digit "0" or the characters "ALL" (case insensitive). I am not sure that this agrees with your idea of numeric '0'. (it will match the strings such as "0h, my" or "007") You probably do not intend it to match a mixed case string such as "aLl oR NoTHinG", but it will. It is often difficult to specify all the special cases correctly. It is impossible to get the regular expression right before you do. Bill	[reply] [d/l]
Re: Testing a command line argument by james28909 (Deacon) on Dec 10, 2015 at 17:37 UTC
try: `if ( $ARGV[1] =~ (/^ALL\|0)$/i) )` [download] Ive noticed that when using 'eq' it likes to use `''` instead of `//`. So try swapping the `eq` to `=~`	[reply] [d/l] [select]
Re^2: Testing a command line argument by choroba (Cardinal) on Dec 10, 2015 at 17:46 UTC
That's wrong. `Unmatched ) in regex; marked by <-- HERE in m/^ALL\|0) <-- HERE $/` [download] ($q=q:Sq=~/;[c](.)(.)/;chr(-\|\|-\|5+lengthSq)`"S\|oS2"`map{chr \|+ord }map{substrSq`S_+\|`\|}3E\|-\|`7**2-3:)=~y+S\|`+$1,++print+eval$q,q,a, [download]	[reply] [d/l] [select]
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