Re: How to specify a dependence on a directory?

[Peng Yu]

On Fri, Nov 20, 2009 at 6:15 PM, John Calcote <address@hidden> wrote:
> On 11/20/2009 4:18 PM, Peng Yu wrote:
>>
>> On Fri, Nov 20, 2009 at 5:11 PM, David Boyce<address@hidden>  wrote:
>>
>>>
>>> On Fri, Nov 20, 2009 at 5:42 PM, Peng Yu<address@hidden>  wrote:
>>>
>>>>
>>>> Is there way to specify a dependence on a directory?
>>>>
>>>> directory: somefile
>>>>  some_command
>>>>
>>>> If any file in 'directory' is older than 'somefile', then I want to
>>>> run 'some_command'. I'm wondering how to do this.
>>>>
>>>
>>> Then you don't want a dependence on a directory. You want to depend on
>>> the full set of files _within_ the directory, a very different thing.
>>> I suspect $(wildcard $(dir)/*) is what you want.
>>>
>>
>> But if there are no files in the directory, I still want some_command
>> to run. How to do it?
>>
>
> In that case, you don't want $(wildcard $(dir)/*). Rather, you want an
> explicit list of files you expect to find in that directory after the
> commands are executed.

But I don't want to explicitly specify the files, because I might
change 'some_command' to generate different files.  I don't want to
modify Makefile every time I change 'some_command'.