Re: [RFC/PATCH] Implement poor-man's submodule support using commit hooks

From: Rogan Dawes <discard@dawes.za.net>
Date: Dec 20, 2006, 14:33 UTC
Message-ID: <458949C4.1020207@dawes.za.net>
In-Reply-To: <200612201347.13805.andyparkins@gmail.com>

Andy Parkins wrote:

Show 12 quoted lines

> On Wednesday 2006 December 20 13:29, Johannes Sixt wrote:
> 
>>> +       cat "$GITMODULES" |
>> useless-use-of-cat-syndrome
> 
> I tried 
> 
>  while
>  do 
>  done < file1 > file1
> 
> And that didn't work.

It wouldn't, since the redirection overwrites the file at the same time as trying to read from it. A better way is to redirect to a temp file, and rename it if the previous operation was successful.

e.g.

0 $ echo true > t 0 $ sed 's/true/false/g' < t > t~ && mv t~ t || rm t~ 0 $ cat t false

and

0 $ echo true > t 0 $ (sed 's/true/false/g' < t > t~; false) && mv t~ t || rm t~ 0 $ cat t true 0 $ ls t~ ls: t~: No such file or directory 2 $