Hello, I just encountered a problem where when the search pattern starts with a dash, grep interprets it as an argument parameter. It does not matter in what kind of quotes the pattern is wrapped. See examples below. $ echo "- break -" | grep "- break -" grep: invalid option -- ' ' Usage: grep [OPTION]... PATTERNS [FILE]... Try 'grep --help' for more information. $ echo "- break -" | grep '- break -' grep: invalid option -- ' ' Usage: grep [OPTION]... PATTERNS [FILE]... Try 'grep --help' for more information. $ echo "- break -" | grep '^- break -' - break - $ echo "- break -" | grep "^- break -" - break - $ echo "- break -" | grep "-s break -" grep: invalid option -- ' ' Usage: grep [OPTION]... PATTERNS [FILE]... Try 'grep --help' for more information.
grep Version: grep (GNU grep) 3.7 Sincerely, Gazi
