How can I convert a string number to a number in Perl?

Perl script to replace a number with its double?

• Hi, I need a perl script to replace a string something like time 10 (number varies) to time 20.can it done using sed or awk command. Whats the best way to do this

• Answer:

  It's a fairly simple problem: $string =~ s/(?<=time )([0-9]+)/$1 * 2/e. The (?<=...) construct is a positive lookbehind. It says "match this text, don't include it in the regular expression. This ensures that the right side of the substitution only replaces the number and not the "time " text. The parentheses around the [0-9] character class capture it to the $1 variable and the /e switch at the end of the substitution says "execute the code on the right side of the substitution and replace the left side with the results of the left. However, I can't provide a full script because it's not at all clear to me what you're really trying to do.