Replace an entire string using regex in Perl

Question

I would like it to look something like this.

my $str = 'axxxx';

my $replacement = 'string_begins_with_a';

$str =~ s/^a/$replacement/;

print "$str\n"; #should print 'string_begins_with_a'

Wiktor Stribiżew · Accepted Answer · 2016-11-16 10:15:15Z

2

You just need to consume the rest of the line by adding .* after a:

my $str = 'axxxx';
my $replacement = 'string_begins_with_a';
$str =~ s/^a.*/$replacement/;
print "$str\n"; #prints 'string_begins_with_a'

Or, you may just check if $str starts with a, and then assign the $replacement value to it:

$str = ($str =~ /^a/) ? $replacement : $str;

or just

if ($str =~ /^a/) {
    $str = $replacement;
}

answered Nov 16, 2016 at 10:15

Wiktor Stribiżew

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2 Comments

Thanks this answer is useful too!

Sorry my bad, I was not aware that you posted yours half a minute earlier.

Wiktor Stribiżew · Accepted Answer · 2016-11-16 17:16:46Z

1

Match the whole string with a ^a.* regex and then replace it using your replacement string.

$str =~ s/^a.*/$replacement/;
print "$str\n"; # would print 'string_begins_with_a'

Wiktor Stribiżew

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answered Nov 16, 2016 at 10:15

Arunesh Singh

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Thanks this what I was looking for!

I do not say you copied from my answer, but that it contains just the same solution. I know that SO has some lags displaying answers.