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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