Bug in csh

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2 total messages Started by Daniel Klein Thu, 25 Apr 1991 18:30

#355

Author: Daniel Klein
Date: Thu, 25 Apr 1991 18:30

13 lines
825 bytes

Well, here's an interesting one! Try typing:

% echo hello & while (1)
? end

The "echo hello" gets executed at each loop of the while.  A similar bug
does not exist with foreach, though.

-- ============ -- =========== -- =========== -- =========== -- =========== --
"The only thing that separates us from the animals is superstition and
mindless rituals" (Latke)      Daniel Klein	CMU-SEI   +1 412/268-7791
						dvk@sei.cmu.edu

Re: Bug in csh

#356

Author: Root Boy Jim
Date: Thu, 25 Apr 1991 18:54

36 lines
1430 bytes

In article <24610@as0c.sei.cmu.edu> dvk@sei.cmu.edu (Daniel Klein) writes:
>
>Well, here's an interesting one! Try typing:
>
>% echo hello & while (1)
>? end
>
>The "echo hello" gets executed at each loop of the while.  A similar bug
>does not exist with foreach, though.

You should know better than to try this. Csh is intrinsicly broken.
Anyway, it's not a bug, it's a feature. It's documented:

	The foreach, switch, and while statements, as well as the
	if-then-else form of the if statement require that the major
	keywords appear in a single simple command on an input line
	as shown below.

Sun says it better:

	Each occurrence of a foreach, switch, while,  if...then  and
	else built-in must appear as the first word on its own input line.

BTW, don't try piping to them or I/O redirection either.

Another broken feature: for integer values of X & Y try:

	(repeat X repeat Y echo foo) | wc -l

What is printed is not X*Y, but rather X+Y-1.

No one cares enuf to fix csh.

-- 
		[rbj@uunet 1] stty sane
		unknown mode: sane

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