I have a growing file . I knew only last few lines which is constant for evey job run. I'd need to pull the Nth record from the last line. In this case i should not use search pattern.
One way - assume you want line #101 from the end
tail -101 filename | head -1
If you want the last line, use:
tail -n 1
How you pull the record from a specific position depends on how the record is delimited and what tools you have available (sed, awk, Perl, etc.).