Shell Programming and Scripting

Hi All,

I am lookig for a way to get all the lines from a log file which has been updated 5 mins prior to the system time.

The log file will be like below:

09:01:00 Started polling
09:01:05 Checking directory test
09:02:00 Error! Cannot access directory test
09:03:00 Polling


I get the system time and calculate 5 mins before the system time. For example if the system time is 09:05, then the script will calculate the time to check as 09:00. Then a sed command will be run to get all the lines below the pattern:

sed '/$time/,$p' $logfile

Which will print all the lines below the pattern. But if the log file does not contain 09:00, no lines will be grepped. Is there a way to solve this issue?

Thanks
D

why don't you first grep for 09:00 and make sure the log is written for 09:00 and if grep succeeds, you proceed with sed... in other case you can increase/decrease the time by 01 min or so.

Why dont you append a line with the time every 5 minutes for you to use then?

Thats a good idea. But the problem is that there are a number of log files in which the command is checking.. in that case we will need to append the time in all the log files.

Code:

#!/bin/sh
five_mins_ago=$(date -d '5 min ago' +%s)
awk -v start=$five_mins_ago '{
        getlogtime="date -d "$1" +%s"
        getlogtime | getline logtime
        if (logtime > start ) print $0
}' $logfile

Another awk solution:

Code:

BEGIN{"date +'%H:%m:%S' --date 'now 5 minutes ago'" | getline sys_time}
$1 >= sys_time {print}

The date -d doesnt work in my version of unix.

Therefore I have been trying to follow the approach by vbe to write a specific line to all the log files in every 5 mins.

But I am facing another issue with sed:

check_param="Fri Aug 28 12:59:14 BST 2009ALERT CHECKPOINT"

Then Im using sed to get all the lines after the above string from the log files like below:

sed -n /$check_param/,$p test.log

But Im getting the error: sed: 0602-404 Function /Fri cannot be parsed.

If I use the string itself instead of the variable, im getting the correct output. I believe I am not using the variable in sed correctly.

Thanks
D