How to Sort Output from several Log Files by date

Question

I have got output from several different log files:

logfile3
2010/07/21 15:28:52 INFO xxx
2010/07/21 15:31:25 INFO xxx
2010/07/21 15:31:25 DEBUG xxx

logfile1
2010/07/21 19:28:52 INFO xxx
2010/07/21 19:31:25 INFO xxx
2010/07/21 19:31:25 DEBUG xxx

logfile2
2010/07/21 13:28:52 INFO xxx
2010/07/21 13:31:25 INFO xxx
2010/07/21 13:31:25 DEBUG xxx

I would like to sort this output by date, but keep the name of the logfile above the log lines, so it should look like:

logfile2
2010/07/21 13:28:52 INFO xxx
2010/07/21 13:31:25 INFO xxx
2010/07/21 13:31:25 DEBUG xxx

logfile3
2010/07/21 15:28:52 INFO xxx
2010/07/21 15:31:25 INFO xxx
2010/07/21 15:31:25 DEBUG xxx

logfile1
2010/07/21 19:28:52 INFO xxx
2010/07/21 19:31:25 INFO xxx
2010/07/21 19:31:25 DEBUG xxx

Do you have any idea how to sort output like this with bash commands, sed or awk? Thanks a lot!

UPDATE: This is the source of the output

for i in $( find log/ -iname *debug*.log -size +0 );do
if [ `grep -c 'ERROR' $i` -gt 0 ];then
 echo -e "\n$i"
 grep 'ERROR' --color=auto -A 5 -B 5 $i
fi
done

Martin

Answer 1

You may be able to get satisfactory results from this (as long as none of your filenames contain colons):

grep -C 5 --recursive 'ERROR' log/* | sort --field-separator=: --key=2

Each line will be prepended by the filename. Your output will look something like this:

logfile2:2010/07/21 13:28:52 INFO xxx
logfile2:2010/07/21 13:31:25 INFO xxx
logfile2:2010/07/21 13:31:25 DEBUG xxx

logfile3:2010/07/21 15:28:52 INFO xxx
logfile3:2010/07/21 15:31:25 INFO xxx
logfile3:2010/07/21 15:31:25 DEBUG xxx
etc.

You can use AWK to reformat that into the format that you show in your example:

grep -C 5 --recursive 'ERROR' log/* | sort --field-separator=: --key=2 |
    awk '{colon = match($0,":"); file = substr($0,1,colon - 1); 
    if (file != prevfile) {print "\n" file; prevfile = file}; 
    print substr($0,colon+1)}'

Here are several improvements to your script, in case you still use it:

find log/ -iname "*debug*.log" -size +0 | while read -r file
do
    if grep -qsm 1 'ERROR' "$file"
    then
        echo -e "\n$file"
        grep 'ERROR' --color=auto -C 5 "$file"
    fi
done