I have never used regular expressions before, but I was wondering how I would search for a string of the form:

[#.#.#.#] or in other words [number.number.number.number]

I am parsing a file and need to extract all of those strings of that form

if( my @captured = $_ =~ m{ \A \[ (\d+) \. (\d+) \. (\d+) \. (\d+) \] \z }msx ){ 
  print "The numbers are: @captured\n"; 
}else{ 
  warn "unrecognized format for $_\n"; 
}

Also something else I am not quite clear on, and maybe this is a stupid question, but will this check every string in the file one line at a time and be able to locate a string in the form [#.#.#.#] Regardless of what else is on that line?

I suppose what I am asking is if the file I am reading is something like:

1 blahblahblahblah [#.#.#.#] blahblah
2 blahblahetc.etc.etc.etc.
3 blahblahblahblah [#.#.#.#] etc.

Will it be able to extract that string from each line, or does the file have to be of the form:

1 [#.#.#.#]
2 [#.#.#.#]
3 [#.#.#.#]

I guess essentially what I am asking is, does this check every string on a line regardless of what all is on that line to check and see if the string is of that form, or will this only check one string per line?

#!/usr/bin/perl 
 
use strict; 
use warnings; 
 
while( <DATA> ){ 
  if( my @captured = $_ =~ m{ \[ (\d+) \. (\d+) \. (\d+) \. (\d+) \] }cgmsx ){  
    print "found @captured\n";  
  } 
} 
__DATA__ 
[0.0.0.0] 
this is a test [232.34.03489.238327983] 
[1.2.3.4] [1.2.3.4] [1.2.3.4] [1.2.3.4] [1.2.3.4]