Usually when searching for keywords, we need to look at the keyword context information, all of which use -A, -B and -C parameters.
Show num rows after matching – grep -A
➜ grep -A 3 "\-A num" man-grep.txt
Show num rows before matching – grep -B
➜ grep -B 3 "\-B num" man-grep.txt
Show num lines before and after matching – grep -C
➜ grep -C 3 "\-C\[num" man-grep.txt
Equivalent to : grep -A 3 -B 3
➜ grep -A 3 -B 3 "\-C\[num" man-grep.txt
When keywords are matched, sometimes matching rows need to be located, using the – n parameter.
grep show line number – grep -n
➜ grep -C 3 -n "\-line\-number" man-grep.txt