sed command for pattern search
 

Hi All,

I have a requirement to search for a particular pattern from the log files every 4 hours. I have set up a cron which runs the script every 4 hours.

Log file pattern as below.

2018-12-17 01:53:47,390 [pool-3-thread-1] INFO [traceId=7c87f067fca636df,spanId=7c87f067fca636df] c.b.s.m.a.update.EmailProcessor - =========== Is email body HTML?

2018-12-17 04:47:21,838 [ActiveMQ Task-1] INFO [traceId=,spanId=] o.a.a.t.failover.FailoverTransport - Successfully connected to tcp://xx.xx.xx.xx:31313

After some research the below sed command was found

But the issue here is , it outputs all the text in the last 4 hours. My requirement is to find if the below pattern exists in the last 4 hours.
c.b.s.m.a.update.EmailProcessor

How to append the pattern in the above code.

Thanks for the help.

looks like homework for me
you may try sed -n and add a second sed expression to look for the specified text.

Some remarks:

• you do not need switch -e if you only have one sed script
• I'm not sure why you use instruction d...
• OK, I see you are using a regex as a line range end. Do you know that the end line number will be the first one that is going to match your regex (maybe not what you want if there are multiple logs in the last 4-hour span), and if there is no match, then every lines will be taken into account?
• do you expect a "yes"/"no" output? If you want that, maybe awk would be more appropriate...

do you have to use sed?
other programs/commands can search inside of files to find a match to, 'c.b.s.m.a.update.EmailProcessor' if true then log it true, if false then log it false.

Hi

I tried the below approach, but couldnot get the result expected .

let's review.
1. set up a cron job to fire off every 4 hours.
2. job is to search log files looking for an entry "c.b.s.m.a.update.EmailProcessor' within same said log files.
3. If found ?? If not found ??

seding for a date within a file is redundant. The log files are already going to be four hours old, every 4 hours, entries are (maybe) added to all of the log files.

So logic states what about the log files condition each 4 hours they are searched, again?

plus your sed statment is malformed.

grep has a return value
sed does not, from what I've read on it thus far.

grep -q

grep retrun code

Indeed, neither your first command, nor the 2nd one can work as is...
If I were you I would do read sed man page (simply type "man sed" in your terminal) and/or do some additional searches on the internet.

As has been asked, why sed? sed stands for stream editor. Your OP says (emphasis added).
IMO, sed is not the appropriate tool. I'd use grep, i.e.
Yes, that will show you the same lines every time it runs...not just the lines added in the last four hours. You'll need to analyze the result and parse it some more to tune the result.

No need to use .* as boundaries for your grep pattern

I knew that...my bad...don't know what I was thinking. Thanks for pointing it out...better for others.;)

C'mon folks, the OP is trying, let's help. And *YES* the command posted originally works exactly as it's supposed to.Close - you need the input file on the first sed, and by using "-n" in the second sed you are suppressing all printing, so you have to explicitly print the lines you want. Try it like this.
As suggested above, it is possibly better to only call sed once

works off return code 1 | 0

or

results.
placed within a bunch of text 3 times, and returned 3 times it was found. Then one could just do the math on each run to see the increments in finds.

there is a space before /home in filename, which make this command useless.
use grep -c instead of grep | wc
And do not repeat the same grep. That is just wasting the resources and time.
grep cannot handle the 4 hours requirement, sed can do the search for you

and probably works:

This was not posted for copy paste efficiency. I just tossed that in here after I pasted it from my test code, that is where the space came from. It was "$1" to use the CLI.

That is a neither, here nor there, due to, if the user OP cannot figure out why it is not working due a space because of a copy paste using of answers in any forum, then it is a good exercise to be used as a learning tool, to test any code gotten from somewhere else before putting to use.
point taken. As one little file is not a good test for reality purposes.