Date: Tue, 18 Jan 2022 12:44:46 +0100
From: l.bash...@scarydevilmonastery.net
Message-ID:
<1642506286.659529.80113.nullmai...@latitude.scarydevilmonastery.net>
| a: defining an empty function will throw a syntax error
| b: defining an empty bodies flow control construct will thow a syntax
error
|
| While it may be debatable whether such construct could serve any purpose
| (they actually can), perceived lack of purpose doesn't qualify them as
| syntactically wrong. They aren't.
They are, and always have been. The sh syntax doesn't permit completely
empty statements, and never has.
| Would they be syntactically wrong,
| the syntax error would continue to exist after adding a harmless
| "no operation" equivalent.
That makes no sense at all. If the question were semantics, that
might be a more reasonable thing to say, but it isn't. The syntax
requires words to exist, ':' is a word (it is even a command, which
is more than is required).
If you want the more elementary case, even less than this, try
E=
fn() { $E; }
(though that one is dangerous, as it is the value of E at the time
the function is called which controls what happens, other than the question
of the syntax, not its value at definition time.
if true then $E; fi
while $E; do $E; done
(the latter is an infinite loop, doing nothing, executing nothing, just
the shell using all the available CPU).
kre
