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One-Shot Throw-Away `awk' Programs
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   Once you are familiar with `awk', you will often type in simple
programs the moment you want to use them.  Then you can write the
program as the first argument of the `awk' command, like this:

     awk 'PROGRAM' INPUT-FILE1 INPUT-FILE2 ...

where PROGRAM consists of a series of PATTERNS and ACTIONS, as
described earlier.

   This command format instructs the "shell", or command interpreter,
to start `awk' and use the PROGRAM to process records in the input
file(s).  There are single quotes around PROGRAM so the shell won't
interpret any `awk' characters as special shell characters.  The quotes
also cause the shell to treat all of PROGRAM as a single argument for
`awk', and allow PROGRAM to be more than one line long.

   This format is also useful for running short or medium-sized `awk'
programs from shell scripts, because it avoids the need for a separate
file for the `awk' program.  A self-contained shell script is more
reliable because there are no other files to misplace.

   Note: Some Simple Examples, presents several short,
self-contained programs.