How to read a specific value from a Log file?

Shell Programming and Scripting
1

Hi,

I have a .log file in which it has many values. But i need some specific values. How it can be done using Shell Script. Please explain in detail.

Thankx in advance.

Sathish D V.

2

it depends.

what does the file look like? Give us its format.

3

Please post here a sample log file and the specific values you are looking for. Please be little more specific, if you want a general answer then I can tell you that to look for specific values in a specific log file there are many tools, like grep, sed, awk, perl, bash, ksh, sh whatsoever suits you.

Regards,
Tayyab

4

Some more details would be nice.

But finding a specific value in a file:

grep <value> <file>

Or multiple values:

egrep "<value1>|<value2>|<value3>" <file>

5

Hi the log file looks like below:

Database Name AAALog BBB Log
#===================================================================#
XXXXXX S0000993.LOG S0000992.LOG
YYYYYY S0002549.LOG S0002549.LOG

I need to print only the difference of the S0000993.LOG and S0000992.LOG using Shell script. If we open 123.log then the output looks as above shown.

Can u suggest how to do this?
Thanks
Sathish D V

6

for eg: you have a logfile called itr.log means and you want to get root name and read that means below is the way.

grep "root" itr.log|read a
echo $a

in the above example you grep for root,then store the grep output in a variable a

then you can echo and check whether stored value is correct

7

You mean you want to print only those lines where both log file names are not identical? Then try something like this:

awk '$2 != $3' 123.log

It'll yeild:

XXXXXX                  S0000993.LOG        S0000992.LOG
8

Hi,
Thank u very much. But i need one more help. I have shown a values as S0000993.LOG, here i need to remove 'S' and '.LOG' from the shown value. And only print '0000993'. Is it possible? If so can please explain?

Thanks and Regards
Sathish D V.

9

You can try using this with the previous command :

awk '$2 != $3' 123.log | sed -e s/S//g -e s/.LOG//g