Query about conditional pattern matching
 

Hello All,

I am trying to count the number of users logged in a particular day using the last and filtering with 'awk, like below:

It worked fine, until I encountered a server whose wtmp contained login information more than a year. so obviously my filtering method above lists current year as well as previous year's info.

Is there any sub-programming in awk or sed to
a) print the lines that contain the pattern
b) stop parsing the file, once the line that does not contain pattern had been reached.

Maybe use the -F option for last and then limit the regex to be between the dates you are looking for.

As for stop parsing the file, you can use the exit command when you reach the point at which you wish to stop.

Hi Grail,

Thanks for the suggestions!.

I added the 'day of the week' in the regex and excluded the previous year's information from the output

However, for non Linux platform, like AIX, last output didnt had a 'day of the week' field. so i used

and it seems to be working :scratch:

Thank you once again!

hmmm ... my suggestion was the option for last not awk, just to be clear.