From: Rogan Dawes <discard@dawes.za.net>
Date: Wed, 20 Dec 2006 14:33:40 GMT
Subject: Re: [RFC/PATCH] Implement poor-man's submodule support using commit hooks
Message-ID: <458949C4.1020207@dawes.za.net>
In-Reply-To: <200612201347.13805.andyparkins@gmail.com>

Andy Parkins wrote:
> 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 $