I have a requirement to search a log file that never rotates for certain values. If I find them I pipe them to a another file. To log file is constanyl being appened with new lines and never rotating Easy so far.

The problem is I dont want to pipe out matches already seen before. One thing I tried was to use sed to put a # at the beginning of each line as it is read. Then the grep would ignore lines starting with #

My problem is I can get it to just add # to the unread lines, it adds another to all lines so each time the log is read so the earliest entries have loads of * infront of them.

I was tryin gto get it to ignore liens with # and then to a for loop for any the new lines e.g. for any not starting with # search for the string and add # to the front. This way is would only add # to lines that dont have one.
Here i swhat I was working with but just cant get that loop to work on lines not starting with #

Any help would be a awesome.

grep -v '^#' test.log | grep "Can not load CRL" This line ignores lines starting with # and greps the rest for "Can not load CRL"

sed 's/^/#/g' test.log > testnew.log The line adds the # to the front and creates output file testnew.log I want it to only add # to lines without a # already

mv testnew.log test.log This line renames\overwrites testnew.log and to test.log If anyone knows how i can write directly to the original file instead of having to write a new file and then overwrite the original would be great as well