Question

I have a string from which I wish to extract a single word, but with a numerical appended to it, which might be different in each line:

This is string1 this is string This is string11  This is string6 and it is in this line 

I want to parse this file and get the values of "stringXXX", starting from 0 to 100

# suppose ABC.txt contains the above lines FH1 = open "Abc.txt";  @abcFile = <FH1>;  foreach $line(@abcFile) {     if ($pattern =~ s/string.(d{0}d{100});         print $pattern; 

The above prints the whole line, I wish to get only stringXXX

Answer 1

you need to capture it:

while ($pattern =~/(string(100|\d{1,2}))/g) {     print $1; } 

Explanation:

• the parentheses capture what’s in them into $1. If you have more than one set of parens, the 1st captures into $1, the 2nd into $2 etc. In this case $2 will have the actual number.
• \d{1,2} captures between 1 and 3 digits, allowing you to capture between 0 and 99. The additional 100 there allows you to capture 100 explicitly, since it’s the only 3-digit number you want to match.

edit: fixed the order of the numbers that are captured.