by John on (#4W7NE)
Suppose you’re looking for instances of -42 in a file foo.txt. The command grep -42 foo.txt won’t work. Instead you’ll get a warning message like the following. Usage: grep [OPTION]... PATTERN [FILE]... Try 'grep --help' for more information. Putting single or double quotes around -42 won’t help. The problem is that grep interprets 42 as […]