CODEWITHSUNDEEP
regexperl
Rao
Rao

Reputation: 1

Not able to extract regex matches, return "1" instead of string

I am seeing strange problem..can someplease please help. I have a log template that looks like this

            CPU load:    0
            Memory load: 7
            User load:   0
            Interface Information:
              eth0: Up
              eth1: Up
            Processes Information:

Now, I login to my device and get the logs like my @output = $ssh->exec("show details"); The output looks similar, as show below but different values for parameters

            CPU load:    21
            Memory load: 27
            User load:   21
            Interface Information:
              eth0: Down
              eth1: Up
            Processes Information:

First I am opening the template file, split it into line by line and when I try to compate it with "show details" output, for the matches, I am getting value 1 as result and not the matched string. Can someone please help.

Code:

my @output = $ssh->exec("show details");
open (FH, "templates/SHOW.txt") || die "Could not open File: $!\n";
@file_array = <FH>;
@TemplateArray = split(/\n/,@file_array);
@matches = split(/\n/,@output);
foreach $keys (@matches) {
   foreach (@TemplateArray) {
     $keys =~ m/($_)/;
     unshift (@result_array, $1);
   }
}
print "\n @result_array\n";

}

I get "1" as result but no string.

Upvotes: 0

Views: 992

Answers (3)

ikegami
ikegami

Reputation: 386461

split's expects a string for its second argument, so

@TemplateArray = split(/\n/, @file_array);

ends up being the same as 

@TemplateArray = split(/\n/, scalar(@file_array));

Keep in mind that scalar(@file_array) returns the number of elements in the array.

@file_array = <FH>;

will populate @file_array as follows:

@file_array = (
    "line1\n",
    "line2\n",
    "line3\n",
);

In other words, it's already split into lines. If you're trying to remove the trailing newlines, you want to replace

@TemplateArray = split(/\n/,@file_array);

with

chomp( my @TemplateArray = @file_array );

I can't help you fix

@matches = split(/\n/,@output);

because I don't know what $ssh contains, and thus I don't know what @output contains.

Please use

use strict;
use warnings;

Upvotes: 0

hexcoder
hexcoder

Reputation: 1220

Adding to TLP's answer, the solution is to change

@matches = split(/\n/,@output);

to

@matches = map { split(/\n/, $_) } @output;

so split() operates on strings from @output.

Upvotes: 0

TLP
TLP

Reputation: 67910

When you use split on an array, the array will be in scalar context, and will only return the number of elements in it. In other words:

@TemplateArray = split(/\n/,@file_array);
@matches = split(/\n/,@output);

is equal to: 

@TemplateArray = $#file_array;
@matches       = $#output;

Which is why you get "1" as a result.

Also, if you are not already doing it:

use strict;
use warnings;

Upvotes: 4

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