I have a file with many lines from the following format
00000000000 00000000 0 MMM_WR 0 000004 00000abc
00000000000 00000000 0 MMM_WR 0 000008 0000000c
...
I want to extract the last 2 words into variables in my perl script and print them
I tried
$line =~ m/^.+ MMM_WR 0\s+(\w+)\s+(\w+)/;
print $1;
print $2;
but $1 and $2 are always uninitialized
any advise? please
You have two spaces before MMM_WR where you should have one.
$line =~ m/^.+ MMM_WR 0\s+(\w+)\s+(\w+)/;
This sort of thing is safer done with split. Split it up on whitespace and grab the fields you want.
my @fields = split(/\s+/, $line);
However, this looks like a fixed width format which is better handled with unpack. See perlpacktut for more on that.
$line =~ m/^.+ MMM_WR 0\s+(\w+)\s+(\w+)/;
This regex expects two spaces in front of MMM_WR
00000000000 00000000 0 MMM_WR 0 000004 00000abc
This line provides only a single space before MMM_WR. Thus, your regex (which expects twp spaces) cannot match. If you fix the regex to only expect a single space it works.
There seems to be only one space before MMM_WR in your data, but the regex contains two.
You can split the string into array and print two last elements
use strict;
use warnings;
use feature 'say';
while(<DATA>) {
my @data = (split ' ')[5,6];
say join ' ', @data;
}
__DATA__
00000000000 00000000 0 MMM_WR 0 000004 00000abc
00000000000 00000000 0 MMM_WR 0 000008 0000000c
Output
000004 00000abc
000008 0000000c
Other variation with regex match
use strict;
use warnings;
use feature 'say';
while (<DATA>) {
my @data;
@data = $_ =~ /MMM_WR\s+\d\s+(\d{6})\s+(.+)/;
say join ' ', @data;
}
__DATA__
00000000000 00000000 0 MMM_WR 0 000004 00000abc
00000000000 00000000 0 MMM_WR 0 000008 0000000c
Output
000004 00000abc
000008 0000000c
The data of interest can be extracted with unpack
use strict;
use warnings;
use feature 'say';
while (<DATA>) {
my @data = (unpack("A45A6A12A8",$_))[1,3];
say join ' ', @data;
}
__DATA__
00000000000 00000000 0 MMM_WR 0 000004 00000abc
00000000000 00000000 0 MMM_WR 0 000008 0000000c
Output
000004 00000abc
000008 0000000c
Variation by utilizing 'substr'
use strict;
use warnings;
use feature 'say';
while (<DATA>) {
my @data;
$data[0] = substr $_, 45, 6;
$data[1] = substr $_, 63, 8;
say join ' ', @data;
}
__DATA__
00000000000 00000000 0 MMM_WR 0 000004 00000abc
00000000000 00000000 0 MMM_WR 0 000008 0000000c
Output
000004 00000abc
000008 0000000c
$line =~ /MMM_WR\s+0\s+(\w+)\s+(\w+)/;to extract data of interest.