Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP
Path: utzoo!mnetor!seismo!cmcl2!lanl!dph
From: dph@lanl.ARPA (David P Huelsbeck)
Newsgroups: net.unix
Subject: Re: passing command line arguments to awk
Message-ID: <7759@lanl.ARPA>
Date: Mon, 22-Sep-86 05:48:21 EDT
Article-I.D.: lanl.7759
Posted: Mon Sep 22 05:48:21 1986
Date-Received: Mon, 22-Sep-86 07:54:22 EDT
References: <731@scc.UUCP>
Reply-To: dph@a.UUCP (David P Huelsbeck)
Distribution: net
Organization: Los Alamos National Laboratory
Lines: 37

In article <731@scc.UUCP> steiny@scc.UUCP (Don Steiny) writes:
>In article <753@moscom.UUCP>, de@moscom.UUCP (Dave Esan) writes:
>> > 
>> > I surrender  --  is it possible to pass command line arguments to awk?
>> > If so - how.  
>
>	awk ' statement ; . . . ' file
>
>be sure and use single quotes!   Lots of awk characters have
>special meaning to the shell.  The following prints the uids in
>the password file from highest to lowest:
>
>	awk -F: '{ print $3 }' | sort -n -r
>
>
>-- 
>scc!steiny
>Don Steiny @ Don Steiny Software 
>109 Torrey Pine Terrace
>Santa Cruz, Calif. 95060
>(408) 425-0382


This is a special case but an important one. Using the -F<c> option sets the
field separator to the character <c>. This is important because setting the
field separator with:

	awk '{ print $3 }' FS=\":\" | sort -n -r

will not set the FS variable to ":". (at least on 4.2) I haven't checked but
I suspect that it's caused by the fact that parameter values passed from the 
command line are not made available until after the first record has been read
and parsed. Other variables not used in parsing (such as OFS etc.) may be set
in the way I've shown. In the case of RS I know of no way to set it from the
command line.

	dph@lanl.arpa