12.1 Invoking awk

There are two ways to run awk---with an explicit program or with one or more program files. Here are templates for both of them; items enclosed in [...] in these templates are optional:

awk [options] -f progfile [--] file ... awk [options] [--] 'program' file ...

Besides traditional one-letter POSIX-style options, gawk also supports GNU long options.

It is possible to invoke awk with an empty program:

awk '' datafile1 datafile2

Doing so makes little sense though; awk exits silently when given an empty program. (d.c.) If `--lint' has been specified on the command-line, gawk issues a warning that the program is empty.