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Why sh-set-shell insert a space after #!
From: |
Stephen J. Turnbull |
Subject: |
Why sh-set-shell insert a space after #! |
Date: |
Fri, 17 Aug 2012 16:18:07 +0900 |
Leo writes:
> Hello all,
>
> If you M-x sh-set-shell in a buffer it inserts something like:
>
> #! /bin/bash
>
> I am curious why a space after #!. I read this page:
> http://en.wikipedia.org/wiki/Shebang_(Unix). The newsgroup post by
> Dennis Ritchie also has a space. But most scripts I have seen do not. So
> I am curious ;)
IIRC, POSIX allows but doesn't require the space. However, some
historical mostly-compatible shells had problems if there was no
space. Since it never hurts with fully conforming shells, and
sometimes helps, it's a definite portability win. (AFAIK there was no
particular correlation between this kind of non-conformance and other,
more important, non-conformance.)
Although it's not needed for bash, you can argue for it from
simplicity of sh-mode implementation (you don't need to detect the
shell and maintain a list of which shells care to decide whether to
insert the space) and consistency of style.
Re: Why sh-set-shell insert a space after #!, Aurélien Aptel, 2012/08/24
Why sh-set-shell insert a space after #!,
Stephen J. Turnbull <=