Re: semicolon at beginning of line

[Linda Walsh]

Elliott Forney wrote:

> I wish bash would happily execute lines that begin with a semicolon,
> i.e., treat it as a no-op followed by a command.  The following
> examples come to mind:
>
> $ infloop& echo hello 
> hello 
> $ infloop&; echo hello
> bash: syntax error near unexpected token `;'
> $ echo hello; echo world
> hello       ; > world
> $ echo hello;; echo world
> bash: syntax error near unexpected token `;;' ***
> $ ; echo hello world
> bash: syntax error near unexpected token `;'
>
> Any thoughts?

---

I like it (which probably isn't good with this crowd) -- but I think
the case I marked with *** could be more challenging -- since ;; is a
language token closing ")" in a case statement.  But other than that,
a semi-colon being a substitute for a "\n", when it would
otherwise return a "semi-colon unexpected" message seems reasonable --
at least in non-posix mode (posix may require it...can't do anything
'different' there or risk incompats)

If it needs a value, a semi-colon wouldn't be a substitute for a value any
more than a newline, so

  while;do;done

wouldn't be expected to work as you need a statement after 'while' and 'done' to 
be eval'ed.

I've often wondered why it wasn't that way myself, but assumed I'd be told "it 
just has to be that way, because....xxyz" (posix, or parser or something...).. 
it makes too much sense not to do it for it not to have been done already..

Linda
(oft' resident contrarian)