Path: utzoo!utgpu!water!watmath!clyde!att!osu-cis!tut.cis.ohio-state.edu!mailrus!ames!amdahl!pacbell!ditka!rpp386!jfh
From: jfh@rpp386.Dallas.TX.US (The Beach Bum)
Newsgroups: comp.lang.c
Subject: Re: What does Z["ack"] = 5 mean?
Message-ID: <7607@rpp386.Dallas.TX.US>
Date: 6 Oct 88 04:27:31 GMT
References: <14999@agate.BERKELEY.EDU>
Reply-To: jfh@rpp386.Dallas.TX.US (The Beach Bum)
Organization: River Parishes Programming, Dallas TX
Lines: 38

In article <14999@agate.BERKELEY.EDU> laba-3aw@web.berkeley.edu (Sam Shen) writes:
>Exactly what does this mean:
>
>main()
>{
>	char Z;
>
>	Z["ack!"] = 5;
>}

The same as

	char Z;

	"ack!"[Z] = 5;

>This doesn't look right to me.  However, cc doesn't complain
>at all about it.  Lint says:
>
>blah.c(5): warning: Z may be used before set

Right.  It should be

	char Z = 0;

to give Z a reasonable value.

That would produce code to change the 'a' in "ack!" to a \005, which is ^E.

>Worse yet, the executable produced by gcc core dumps.  Oh, by the way, this
>is all on a Sun-3/50.

And well it should.
-- 
John F. Haugh II (jfh@rpp386.Dallas.TX.US)                   HASA, "S" Division

      "Why waste negative entropy on comments, when you could use the same
                   entropy to create bugs instead?" -- Steve Elias