[9fans] is there any good reason why awk does this?

[9fans] is there any good reason why awk does this?

[boyd]

brahma% awk 'END {exit "foo"}' /dev/null ; echo $status

brahma% awk 'END {exit 1}' /dev/null ; echo $status
awk 8186: 1

Re: [9fans] is there any good reason why awk does this?

[Charles Forsyth]

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same reason as this, i suspect:

awk 'END {print 1 * "hello"}' /dev/null
0

the rules aren't really given in the manual page except perhaps
by implication in the BUGS, but in a context where a number is
expected (operand of arithmetic operator) the string is converted
to a number, and "hello" or "foo" are both zero, but "5hello" is 5.
exit takes an expression but doesn't say whether it's integer or
string (but it's integer, as usual on Unix).

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From: boyd@sdgm.net
To: 9fans@cse.psu.edu
Subject: [9fans] is there any good reason why awk does this?
Date: Sun, 31 Aug 2003 22:50:34 -0400
Message-ID: <1ef339d30bfee33810aa4e1d0c4488af@sdgm.net>

brahma% awk 'END {exit "foo"}' /dev/null ; echo $status

brahma% awk 'END {exit 1}' /dev/null ; echo $status
awk 8186: 1

Re: [9fans] is there any good reason why awk does this?

[boyd, rounin]

i think awk should be able to exit with a string like everything
else does/should with exits().

Re: [9fans] is there any good reason why awk does this?

[rob pike, esq.]

> i think awk should be able to exit with a string like everything
> else does/should with exits().

it's ported from and maintained as a posix program; it calls exit.
regex wasn't kept compatible, though, so i suppose exit could
go too, but it seems not worth the trouble.

Re: [9fans] is there any good reason why awk does this?

[boyd, rounin]

> it's ported from and maintained as a posix program; it calls exit.
> regex wasn't kept compatible, though, so i suppose exit could
> go too, but it seems not worth the trouble.

i 'call bullshit on dat'.

this plan 9 and we have exits(2).

i'll fix it if someone will apply it to the source tree.

Re: [9fans] is there any good reason why awk does this?

[Joel Salomon]

On Mon, 1 Sep 2003, boyd, rounin wrote:

> i think awk should be able to exit with a string like everything
> else does/should with exits().
>

Taking the original example:
>brahma% awk 'END {exit "foo"}' /dev/null ; echo $status
>
>brahma% awk 'END {exit 1}' /dev/null ; echo $status
>awk 8186: 1
I would guess that awk *is* using exits() but first exit converts is arg
to a number (if necessary), presumably for compatability w/ unix awk,
then converts the num to a string which gets sent to exits().

Ugh.

--Joel

Re: [9fans] is there any good reason why awk does this?

[Dan Cross]

That's right.  Awk was brought in under the ape, and so doesn't really
do exits....

	- Dan C.

Re: [9fans] is there any good reason why awk does this?

[boyd, rounin]

> That's right.  Awk was brought in under the ape, and so doesn't really
> do exits....

bugger it, i'm porting it away from ape.

Re: [9fans] is there any good reason why awk does this?

[Douglas A. Gwyn]

boyd, rounin wrote:
> bugger it, i'm porting it away from ape.

But there is still a specification for awk to which
I urge you to conform.  awk runs on a multitude of
platforms and it would be nice if awk programs were
portable.

Re: [9fans] is there any good reason why awk does this?

[Lyndon Nerenberg]

> > bugger it, i'm porting it away from ape.
> But there is still a specification for awk to which
> I urge you to conform.

awk?
nawk?
gawk?
mawk?
bawk?
squawk?

Frobbing exit[s] (and making it grok UTF-8?) are not evil designs on life,
the universe, and everything.

--lyndon

Re: [9fans] is there any good reason why awk does this?

[boyd, rounin]

> Frobbing exit[s] (and making it grok UTF-8?) are not evil designs on life,
> the universe, and everything.

it will behave just like it does now on plan 9 except you can go:

    exit "foo"

now testing it is probably going to be a bugger.

i did find this bug:

/dev/std* were being used instead of /fd/*

Re: [9fans] is there any good reason why awk does this?

[Russ Cox]

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I think you're wrong.  The only occurrence of /dev/std* in the source
is in a table that makes them work in awk programs.  That is,

awk 'BEGIN {print "hello world" >"/dev/stderr" }'

works because of that table.  It's not a bug.

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From: "boyd, rounin" <boyd@insultant.net>
To: <9fans@cse.psu.edu>
Subject: Re: [9fans] is there any good reason why awk does this?
Date: Wed, 3 Sep 2003 14:20:28 +0200
Message-ID: <01cb01c37215$c5a7e420$b9844051@insultant.net>

> Frobbing exit[s] (and making it grok UTF-8?) are not evil designs on life,
> the universe, and everything.

it will behave just like it does now on plan 9 except you can go:

    exit "foo"

now testing it is probably going to be a bugger.

i did find this bug:

/dev/std* were being used instead of /fd/*

Re: [9fans] is there any good reason why awk does this?

[boyd, rounin]

> I think you're wrong.  The only occurrence of /dev/std* in the source
> is in a table that makes them work in awk programs.  That is,
>
> awk 'BEGIN {print "hello world" >"/dev/stderr" }'

noted.

> works because of that table.  It's not a bug.

maybe.

Re: [9fans] is there any good reason why awk does this?

[boyd, rounin]

> awk 'BEGIN {print "hello world" >"/dev/stderr" }'

you're right.  i've un-broken it.

Re: [9fans] is there any good reason why awk does this?

[Ralph Corderoy]

boyd wrote:
> it will behave just like it does now on plan 9 except you can go:
>
>    exit "foo"

What will it do for

    exit foo

Cheers,

--
Ralph Corderoy.      http://inputplus.co.uk/ralph/     http://troff.org/

Re: [9fans] is there any good reason why awk does this?

[boyd, rounin]

 > What will it do for
>
>     exit foo

smash it into a string.

Re: [9fans] is there any good reason why awk does this?

[Ralph Corderoy]

Hi boyd,,

> > What will it do for
> >
> >     exit foo
>
> smash it into a string.

Oh dear.  Why not leave awk's `exit' alone so it works as every awk
script in the world expects and add `exits'?

Cheers,


Ralph.

Re: [9fans] is there any good reason why awk does this?

[boyd, rounin]

> Oh dear.  Why not leave awk's `exit' alone so it works as every awk
> script in the world expects and add `exits'?

nope.  it's smashed into a string _anyway_.

Re: [9fans] is there any good reason why awk does this?

[boyd, rounin]

> awk runs on a multitude of platforms and it would be nice if
> awk programs were portable.

that's always been the plan.