Re: [PATCH v3 1/6] t9001: non order-sensitive file comparison

> Junio C Hamano <gitster@pobox.com> writes:
> 
>> Tom Russello <tom.russello@grenoble-inp.org> writes:
>>
>>> +# Check if two files have the same content, non-order sensitive
>>> +test_cmp_noorder () {
>>> +	sort $1 >$1;
>>
>> Here is what I think happens:
>>
>>     0) the shell parses this command line;
>>     1) the shell notices that the output has to go to $1;
>>     2) the shell does open(2) of $1,
>>     3) the shell spawns "sort" with a single argument, with its
>>        output connected to the file descriptor obtained in 2).
>>
>> Because "$1" becomes an empty file at 2), "sort" reads nothing and
>> writes nothing.
> 
> Tom: in case you're not convinced, try this:
> 
> $ (echo b; echo a) >f
> $ sort f
> a
> b
> $ sort f >f
> $ cat f
> $
> 
> Also, useless ';' and missing double-quotes around "$1" to avoid bad
> surprises ifever test_cmp_noorder is called on file names with special
> characters.