> -----Original Message-----
> From: Chris Stinemetz [mailto:[email protected]]
> Sent: Tuesday, December 20, 2011 9:22 AM
> To: Saravanan Murugaiah
> Cc: [email protected]
> Subject: Re: Help in search concept
>
> >
> > I am a learner in Perl and this is my first post in this group. I
> need
> > to search a word "Test 1.2.1" in my file. I am using "$_ =~m/Test
> > \d+", but it searched only "Test 1" not the full content. I need to
> > check whether it is "Test 1" or "Test 1.2" or "Test 1.2.1". Kindly
> > help me in this regard
> >
>
> Hello MadYuv,
>
> I'm sure there is a much cleaner way of writing the regular expression.
> I am in the process of learning regular expression Perl flavour myself.
>
> Below is sample program I came up with below:
>
> HTH,
>
> Chris
>
> #!/usr/bin/perl
> use warnings;
> use strict;
>
> while(<DATA>) {
> chomp;
> if($_ =~ m/(Test\s+\d\.\d\.\d)/){
> print "$1\n";
> }
> }
>
> __DATA__
> Test 1.2.1
> Test 1.2.1
> Test 1.2.1
> Test 1.2.1
> Test 1
> Test 1.2
>
> ***OUTPUT***
> Test 1.2.1
> Test 1.2.1
> Test 1.2.1
> Test 1.2.1
>
Hi Chris,
Note that your regular expression requires that 'Test' be followed by
whitespace and then exactly one digit followed by a period followed by a
single digit followed by a period followed by another single digit.
It does not account for '1' or '1.2'. Also, although the OP does not
specify, the numbers could be more that single digits.
Below I give an example using a quoted regular expression with the 'x'
modifier to allow comments and whitespace (including newlines) to be ignored
- the better to document what you are trying to accomplish.
HTH,
Ken
use strict;
use warnings;
my $matchRE = qr/
( # Start grabbing $1
Test # Literal 'Test'
\s+ # one or more whitespace characters
\d+ # one or more numeric characters
(?: # Do not capture match in parentheses
\. # literal period|dot character
\d+ # one or more numeric characters
)* # match in parentheses is optional
# and can occur multiple times
) # End of parentheses capturing $1
/x;
while(<DATA>) {
chomp;
if(/$matchRE/) {
print "$1\n";
}
}
__DATA__
Test 1.2.1
Test 1.2.12
Test 1.21.1
Test 1.21.12
Test 1.21.12.1
Test 1
Test 1.2
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