How to extract special charachetrs like <=, >= != from string

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

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Re: How to extract special charachetrs like <=, >= != from string by james28909 (Deacon) on Aug 14, 2015 at 05:27 UTC
If all your trying to do is extract those specific characters, then this might work for you: `use strict; use warnings; while (<DATA>) { print "$1\n" if $_ =~ /(!=\|<=\|>=\|==)/; } __DATA__ $this <= $that $this lt $that $this >= $that $this gt $that $this != $that $this ne $that $this == $that $this eq $that` [download] I do suggest you read up on Regular Expressions as it will help you out tremendously on your journey :)	[reply] [d/l]
Re^2: How to extract special charachetrs like <=, >= != from string by vinoth.ree (Monsignor) on Aug 14, 2015 at 05:49 UTC
We can even shorten this with character class [] `use strict; use warnings; use Data::Dumper; while(<DATA>) { print "$1\n" if($_ =~ /([><=!]+)/g) } __DATA__ $this vinoth $that $this >= $that $this gt $that $this != $that $this ne $that $this == $that $this eq $that` [download] *All is well. I learn by answering your questions...*	[reply] [d/l]
Re^3: How to extract special charachetrs like <=, >= != from string by Anonymous Monk on Aug 14, 2015 at 08:13 UTC
Hi all, Solution provided by james28909 did work for me. thanks --girija	[reply]
Re^3: How to extract special charachetrs like <=, >= != from string by james28909 (Deacon) on Aug 14, 2015 at 05:52 UTC
My question to this is, how does it know to print the `=` after the `><=!` ? Maybe i am missing a key piece of data/knowledge which would not surprise me lol.	[reply] [d/l] [select]
Re^4: How to extract special charachetrs like <=, >= != from string by choroba (Cardinal) on Aug 14, 2015 at 05:58 UTC
Re^4: How to extract special characters like <=, >= != from string by soonix (Chancellor) on Aug 14, 2015 at 06:44 UTC
Re^4: How to extract special charachetrs like <=, >= != from string by vinoth.ree (Monsignor) on Aug 14, 2015 at 06:30 UTC
Re^5: How to extract special charachetrs like <=, >= != from string by james28909 (Deacon) on Aug 14, 2015 at 06:45 UTC
Some notes below your chosen depth have not been shown here
Re: How to extract special charachetrs like <=, >= != from string by NetWallah (Canon) on Aug 14, 2015 at 05:41 UTC
<, > = and ! are not that "special" for regular expressions. They can be used inside a "[ ] Bracketed Character class" with capture (see perldoc perlre). `perl -e '($x=shift()) =~/([=<>!]+)/ and print "\[$x] has \[$1]\n"' "Ra +nge is != 4%" [Range is != 4%] has [!=]` [download] Clarity: it's like that one thing that is not the other thing, except for when it is.	[reply] [d/l]
Re: How to extract special charachetrs like <=, >= != from string by anonymized user 468275 (Curate) on Aug 14, 2015 at 11:03 UTC
There is a named posix class `[[:punct:]]`for characters such as these which are none of \w, whitespace nor control characters. See perlrecharclass Update: `my @puncts = /([[:punct:]]+)/g;` [download] One world, one people	[reply] [d/l] [select]