CODEWITHSUNDEEP
javashellgrep
Himanshu Sharma
Himanshu Sharma

Reputation: 580

Parsing Log Files With grep for Every 5 minutes interval

I am using trilead ssh2 to make ssh connection and parse the log files for every 5 minutes before.

I am using this syntax:-

grep '29/Jan/2018:[0-0][6-6]:[1-2][6-1]' /root/nohup.out>/tmp/nohup.txt

Basicaly I am building an android app which will parse log file for every 5 minutes interval and store it into /tmp/nohup.txt and will download and parse it to find the exceptions and show user those exception notification etc. 

String  parsingCommand="grep"+" ' "+day2+"/"+month2+"/"+year2+":"+"["+hour2/10+"-"+hour1/10+"]"+"["+hour2%10+"-"+hour1%10+"]"+":"+"["+minute2/10+"-"+minute1/10+"]"+"["+minute2%10+"-"+minute1%10+"]"+" ' "+"/root/nohup.out"+">"+"/tmp/nohup.txt";

Here minute1 = current minute fetched from server & minute2= minutes reduced by 5 minutes

grep '29/Jan/2018:[0-0][6-6]:[1-2][6-1]' /root/nohup.out>/tmp/nohup.txt

Here in this case minutes interval is 16-21.

I think i am not using proper regular expression .Because

grep '29/Jan/2018:[0-0][6-6]:[1-2][1-6]' /root/nohup.out>/tmp/nohup.txt

Its working.

Any help would be appreciated. Although so many answer are already here in stackoverflow:-

grep last 2 minutes of log?

https://superuser.com/questions/439688/how-to-grep-a-log-file-within-a-specific-time-period

Upvotes: 1

Views: 1381

Answers (2)

Madie
Madie

Reputation: 241

for the below input:

  2018-01-29 08:00:30,393  
  2018-01-29 08:02:00,003   
  2018-01-29 08:03:00,210 
  2018-01-29 08:01:00,401  
  2018-01-29 08:01:00,401  
  2018-01-29 08:05:00,401   
  2018-01-29 08:16:00,002
  2018-01-29 08:17:00,002
  2018-01-29 08:18:00,002
  2018-01-29 08:19:00,002
  2018-01-29 08:20:00,002
  2018-01-29 08:21:00,002

if you try running this regex:

  2018-01-29 08:(0[0-4]|1[6-9]|2[0-1])

you will see a perfect match for 5 min. You will have to use the or operator for multi pattern matching.The way you re building the regex , you will have to do a lot of calculations. To save so much effort the solution provided by Daniel is proper as per your need.

Upvotes: 1

Daniel
Daniel

Reputation: 1594

I would use non capturing groups and "or":

egrep '29/Jan/2018:(?:(?:06:16)|(?:06:17)|(?:06:18)|(?:06:19)|(?:06:20)|(?:06:21))' /root/nohup.out>/tmp/nohup.out

Your current solution would also get entries from 06:11 and on the other hand miss entries from 06:20.

To include the date in the groups would even be better. Otherwise you could get problems at midnight:

egrep '(?:28/Jan/2018:23:59)|(?:29/Jan/2018:00:00)|(?:29/Jan/2018:00:01)|(?:29/Jan/2018:00:02)|(?:29/Jan/2018:00:03)' ...

You can accomplish that by using a StringBuilder:

public String getGrepCommand(final Date start) {
    Calendar cal = Calendar.getInstance();
    StringBuilder bld = new StringBuilder();

    cal.setTime(start);
    for (int i = 0; i < 5; ++i) {
        bld.append("|(?:");
        bld.append(String.format("%1$td/%1$tb/%1%tY:%1$tH:%1$tM", cal.getTime()));
        bld.append(")");
        cal.add(Calendar.MINUTE, 1);
    }

    if (bld.length() > 0) { // should be ;)
        bld.delete(1, 1);
    }

    return bld.toString();

}

Upvotes: 2

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