awk syntax

[Arnold Robbins]

Submitted-by: arnold%audiofax.com at mathcs.emory.edu (Arnold Robbins)

>In article <1991May14.185737.15746 at uunet.uu.net> arnold at audiofax.com writes:
>> One of the things that happened when new awk was first realeased was a lot
>> of cleaning up and consistencizing (if I may coin a term) of the awk 
>> language.

In article <1991May15.165824.6896 at uunet.uu.net> peter at ficc.ferranti.com (Peter da Silva) writes:
>I don't see how that makes things any more consistent. If you look at the
>grammer there's no ambiguity that needs to be resolved by adding that
>semicolon. Does anyone have an idea what the reasoning behind this was?
>To me, it adds confusion by treating a block as a statement.

This is getting off the topic of standards, but what the heck.  You
ommitted my rationalization of the consistency.  To rephrase: statements
at the rule level should be consistent with statements inside an action.
Statements in a action are separated by newline or semi-colon, therefore
rules (patterns plus actions) should also be separated by newlines or
semi-colons.  It is illegal to type

	{ i = 1  j = 2 }

in an action without the semicolon or newline between the assignments.
Therefore it "should" be illegal to type rules without the separator.
(So yes, block are statements.  This makes sense, since they're executed
in the order they occur in the program.)

As I also mentioned, modern implemenations of 'nawk' (V.4 nawk, gawk)
accept rules with or without the semicolon, so it doesn't really matter.
(Many C compilers continue to accept `i =+ 1' but that doesn't make it
good programming practice...)

>Oh, and my V.3.2 system has no problem with that:
>
>% ls -l | awk 'NF==9 { h[$3] += $5 } END {for(i in h) print i,h[i]}'
>root 7985
>peter 731662

You typed "awk", no 'n'.  My example used "nawk", with an 'n'.    Try

	awk 'BEGIN { foo() }
		function foo () { print "hi" }'

on your V.3.2 system and watch "awk" (no 'n') barf all over your screen.
We're talking two very different animals here.

For whatever it's worth, the V.3.2 nawk man page said that in the "next
major release" nawk would become 'awk' and old awk would become 'oawk'.
This doesn't seem to have happened in V.4.  It probably never will in
System V.  4.4BSD will most likely ship gawk for it's version of awk.

Next topic, please?
-- 
Arnold Robbins				 AudioFAX, Inc. | Threads are the
2000 Powers Ferry Road, Suite 200 / Marietta, GA. 30067 | lack of an idea.
INTERNET: arnold at audiofax.com  Phone:   +1 404 618 4281 |     -- Rob Pike
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[ He's right.  I've cross-posted this to comp.unix.questions, with
  followup's directed there. -- mod ]

Volume-Number: Volume 23, Number 72