Control characters in the shell

Moderator, John S. Quarterman std-unix at longway.TIC.COM
Fri Mar 23 09:35:10 AEST 1990


From: Maarten Litmaath <uunet!cs.vu.nl!maart>

In article <589 at longway.TIC.COM>,
	karl at IMA.IMA.ISC.COM (Karl Heuer) writes:
)...
)Proposal: Reserve $\ (dollar-backslash) as a new entity that begins a C-like
)escape, so we would have $\a $\b $\t $\n $\v $\f $\r, octal escapes like
)$\177, and hex escapes like $\x7F.
)
)Alternative proposal (from a suggestion by Eric Gisin, eric at mks.com): make a
)new string quoting mechanism, $"...", which is just like "..." except that, in
)addition to the four current backslash escapes \$ \` \" \\ that are permitted
)inside double quotes, all the C-like escapes \a etc. would be recognized.

Good idea!
But why not allow *both* syntaxes?  The first would be a simple form of
the second:

	$\a
equals
	$"\a"

...just like:

	$foo
and
	${foo}

When you only want a single control character, you'd use the first form,
when you want some escape codes in a row (possibly containing `normal'
characters as well), you'd use the second form.
--
 1) Will 4.5BSD have wait5()?         |Maarten Litmaath @ VU Amsterdam:
 2) Sleep(3) should be sleep(2) again.|maart at cs.vu.nl, uunet!mcsun!botter!maart

Volume-Number: Volume 19, Number 23



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