in reply to regex trouble

Works for me. 
perl -e 'my $x=q|v09.11-e020|;$x =~  m/^v[0-9][0-9]\.[0-9][0-9]-[a-z][
+0-9][0-9][0-9]/ and print " match\n"'
#Prints ' match'

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You may want to make the regex somewhat shorter: 
 m/^v\d{2}\.\d{2}-[a-z]\d{3}/

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     Theory is when you know something, but it doesn't work.
    Practice is when something works, but you don't know why it works.
    Programmers combine Theory and Practice: Nothing works and they don't know why.         -Anonymous

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Re^2: regex trouble
by blackgoat (Acolyte) on Mar 05, 2010 at 06:31 UTC
    But if there's a lot of text like a paragraph, and this string needs to be picked out and copied, then how should i do it?? can u pls help??
[reply]

      You need to capture it (note the parentheses): 

      #!/usr/bin/perl -l

my $para = "xyz-xyz-xyz-xyz-v09.11-e020xyz-xyz-xyz-";

my ($string) = $para =~ m/(v\d{2}\.\d{2}-[a-z]\d{3})/;

print $string;   # v09.11-e020

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[reply]
[d/l]
        okay... thanks!!
[reply]

      Matching by itself only checks whether a string conforms to a pattern that you defined in the regular expression.

      You capture strings using brackets - ( ).

      If you have only one string to capture, then the way that almut suggested will work.

      If you have more than one string, you have several ways to capture them:

      First way:

      #!/usr/bin/perl -l

my $para = "xyz-xyz-xyz-xyz-v09.11-e020xyz-xyz-xyz-";

my ($part1, $part2) = $para =~ m/(v\d{2}\.\d{2})-([a-z]\d{3})/;

print "$part1, $part2";   # v09.11, e020

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      Second way:

      #!/usr/bin/perl -l

my $para = "xyz-xyz-xyz-xyz-v09.11-e020xyz-xyz-xyz-";

if ($para =~ m/(v\d{2}\.\d{2})-([a-z]\d{3})/) {
    my ($part1, $part2) = ($1, $2); # the variables $1 and $2 are crea
+ted automatically after a successful match
    print "$part1, $part2";   # v09.11, e020
}

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      Third way - very readable, but will only work in Perl 5.10:

      #!/usr/bin/perl -l

my $para = "xyz-xyz-xyz-xyz-v09.11-e020xyz-xyz-xyz-";

if ($para =~ m/(?<part1>v\d{2}\.\d{2})-(?<part2>[a-z]\d{3})/) {
    print "$+{part1}, $+{part2}";   # v09.11, e020
}

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      (You should probably pick better names that "part1" and "part2". I only gave them as an example.)

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[d/l]
[select]

        I have to run a command in unix. And I have to match this expression from whatever output I get. I tried doing the following:

        my $var = 'command';
my ($exp) = $var =~ m/(v\d{2}\.\d{2})-([a-z]\d{3})/;

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        The same is followed by a html script in which the value of $exp must appear. But I am unable to do so...

        Can u pls help!

        Thanks

        BG

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[d/l]

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