http://www.perlmonks.org?node_id=256511

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

Writing some code that builds the VM args string for a java program. I'm completely regex ignorant, was wondering if someone could help...

Given a string containing the following:

-Dname1=2 -Dname2.3="anything" -Djetty.home=c:\a\b\c

or 

-Dname1=2 -Dname2.3="anything" -jetty.home="c:\a\b\c"

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What would be a pattern that matches: 

-Djetty.home=anything_up_to-whitespace_or_eol

or

-Djetty.home="anything_up_to[" or eol]

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make sense? Thanks! Geoff

update (broquaint): title change (was Regex match newbie)

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Re: Regex to match command line arguments
by broquaint (Abbot) on May 08, 2003 at 12:50 UTC
    What would be a pattern that matches:
    Something like this should do the trick 
    my $re = qr/\s -D?jetty\.home= (.+?) (?:\s|$) /x;

/$re/ and print "yup - $1"
  for q[-Dname1=2 -Dname2.3="anything" -jetty.home="c:\a\b\c"],
      q[-Dname1=2 -Dname2.3="anything" -Djetty.home=c:\a\b\c]

__output__

yup - "c:\a\b\c"
yup - c:\a\b\c

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    See. perlre for more info.
    HTH

    _________
    broquaint

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Re: Regex to match command line arguments
by Skeeve (Parson) on May 08, 2003 at 12:48 UTC
    so you want to get the parameter given on the command line? 
    /-Djetty.home=("[^"]*"|\S*)/

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    This should work but doesn't take quotes in quotes into account.
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[d/l]
      Perfect! Thank you wery much!
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Re: Regex to match command line arguments
by jdporter (Paladin) on May 08, 2003 at 13:32 UTC
    If you're just trying to extract the value of the parameter -Djetty.home, then this will work: 
      /-Djetty\.home=(?:(:?"(.*?)")|(\S*))/;

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    but with the caveat that the result (the value of the param) is in $+, not in $1.

    jdporter
    The 6th Rule of Perl Club is -- There is no Rule #6.

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Re: Regex to match command line arguments
by pzbagel (Chaplain) on May 08, 2003 at 14:54 UTC

    I'm not sure your second example data makes sense. But then, I am not familiar with java VM. On a side note, if you are dealing with a number of arguments, a more general solution would be: 

    #If they arguments are in @ARGV
while (shift){
($arg,$val)=split /=/;
$args{$arg}=$val;
}

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    Now you will find all your command line arguments in the hash %args with the argument name as the key, like this: 

    '-Dname1' => 2 
'-Dname2.3' => "anything" 
'-Djetty.home' => 'c:\a\b\c'

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    Hope that's what you are looking for.

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Re: Regex to match command line arguments
by LordWeber (Monk) on May 08, 2003 at 16:21 UTC
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