Used strict and warning but still no error messages when there is supposed to be a mistake somewhere

Question

I have a program that basically opens and reads the syslog in ubuntu and use a keyword text file to search for specific words in the syslog and have that to be outputted into an output text file. Problem is, it was all going well until I can't seem to get any errors anymore which doesn't really help me as there is a mistake somewhere which makes me not see any output at all. I ran my regex using a perl online testing tool and it works but doesnt seem so when I try to run it on the terminal. I would be glad if someone could help me with this.

Here is my code:

#!usr/bin/perl

use strict;  
use warnings;

my $syslogFile = 'syslog';
open (my $syslogInfo, '<', $syslogFile) or die "Could not open $syslogFile";

my $keywordFile = 'keyword';
open (my $keywordInfo, '<', $keywordFile) or die "Could not open $keywordFile";

while (my $line = <$syslogInfo>)
{

    if($line =~ m/[a-zA-Z]\s(\d{1-31})\s(\d{1-24}):(\d{1-59}):(\d{1-59})\s[a-zA-Z]\s($keywordInfo).\ni/)
    {
        open(outputFile, ">>output");

        flock(outputFile, 2);

        print outputFile "$line\n";
    }
}

Edit: Here is a sample of what is in the syslog

Dec 29 22:02:28 osboxes NetworkManager[686]: plen 24 (255.255.255.0)

Your regex doesn't look correct at all. For starters, the first element is for one and only one alphabetical character. I would recommend running your regex through an online tester to make sure it works, such as [https://regex101.com/](https://regex101.com/). — AntonH, Jan 02 '16 at 04:46
`$keywordInfo` is a filehandle... but the rest of your regex is bonkers as well. — Matt Jacob, Jan 02 '16 at 04:51
Also look [here](https://stackoverflow.com/questions/7536755/regular-expression-for-matching-hhmm-time-format) to see a regex to check times. — AntonH, Jan 02 '16 at 04:52
@AntonH Thank you very much for that website helped a lot! But another question though since I cannot find it in the book. How do you add a textfile or string into the regex? — TheNoob, Jan 02 '16 at 05:17
Your shebang line is missing a slash. Should be `#!/usr/bin/perl` — Borodin, Jan 02 '16 at 05:21
Ok i fixed my regex by doing this: /^[a-zA-Z][a-zA-Z][a-zA-Z]\s(\d\d)\s(\d\d):(\d\d):(\d\d)\s[a-zA-Z]*\sNetworkManager.*/s But it still doesn't seem to output anything nor give me any error . (PS. I placed NetworkManager as a test to see if there's an output) — TheNoob, Jan 02 '16 at 05:32
What's `2`? Exclusive lock? Use `LOCK_EX` exported from Fcntl instead. — ikegami, Jan 02 '16 at 22:59

score 4 · Accepted Answer · edited Jan 02 '16 at 14:40

4

You include $keywordInfo in your regex. But $keywordInfo is a filehandle, which means that, when stringified, it will look like "GLOB(0x1819f30)". I suspect that's not the string that you're looking for.

You know how to read data from a filehandle. You're doing that with your other filehandle, $syslogInfo. So you just need to do that with this filehandle too. Something like this:

my $string_to_find = <$keywordInfo>;
chomp $string_to_find;

# Now use $string_to_find in your regex.

edited Jan 02 '16 at 14:40

glenn jackman

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answered Jan 02 '16 at 06:50

Dave Cross

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Oh that helped a lot. Got it working now thank you very much Dave! – TheNoob Jan 02 '16 at 08:34

Used strict and warning but still no error messages when there is supposed to be a mistake somewhere

1 Answers1