CODEWITHSUNDEEP
regexperl
DiegoR
DiegoR

Reputation: 1

Understanding with this regex in Perl without assignment

Can someone explain me how to understand this part of the code The code is extracted from pfLogSumm.pl a log analyzer for postfix mail

while(<>) {
    next if(defined($dateStr) && ! /^$dateStr/o);
    s/: \[ID \d+ [^\]]+\] /: /o;    # lose "[ID nnnnnn some.thing]" stuff
    my $logRmdr;

    more code

}

I can't understand what the regex is doing because don't have a assignment, don't have a conditional, simple is there

Upvotes: 0

Views: 95

Answers (1)

Barmar
Barmar

Reputation: 780889

By default, regular expressions (and many other functions) operate on $_. So 

s/: \[ID \d+ [^\]]+\] /: /o;

is equivalent to:

$_ =~ s/: \[ID \d+ [^\]]+\] /: /o;

This replaces : [ID number ...] with just : in the input line.

This is a common idiom that you should see in many Perl scripts, you should be used to it.

Upvotes: 1

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