How to truncate a string to a specific length in perl?

Question

I am just unable to find "truncate a string to a specific length" in Perl. Is there any built in way?

UPDATE:

input: $str = "abcd";

output (truncate for 3 characters): $str is abc

Answer 1

You want to use the substr() function.

$shortened = substr( $long, 0, 50 ); # 50 characters long, starting at the beginning. 

For more, use perldoc

perldoc -f substr 

In your case, it would be:

$str = 'abcd'; $short = substr( $str, 0, 3 ); 

Answer 2

For a string of arbitrary length, where truncate length can be longer than string length, I would opt for a substitution

$str =~ s/.{3}\K.*//s; 

For shorter strings, the substitution will not match and the string will be unchanged. The convenient \K escape can be replaced with a lookbehind assertion, or a simple capture:

s/(?<=.{3}).*//s   # lookbehind s/(.{3}).*/$1/s    # capture