Grep

grep is a command for searching plain text data sets for lines that match a regular expression.

See also

• ack, ag, grep, egrep, fgrep, agrep, ngrep, pgrep, awk, sed, strings, tr, tail, mtail, git grep, wc, uniq, LogQL, findstr (Windows), rg, git-grep, cut
• include Cisco IOS command
• match PAN-OS command
• Select-String or sls in Powershell
• git grep

http://man7.org/linux/man-pages/man1/grep.1p.html