Experimental Physics and
Industrial Control System

"J. Lewis Muir" <[email protected]> · Tue, 16 Sep 2014 15:16:04 -0500

On 9/16/14, 2:40 PM, Benjamin Franksen wrote:
> Hi Lewis
>
> Gnu make by default uses /bin/sh to execute recipes (one invocation
> per line), which should be a posix conformant(*) shell and thus
> support tilde expansion.  For make itself, the tilde is just another
> character with no special meaning.

Hi, Ben.

Right, I'm aware of that, but the problem is the assumption that the
RULES_JAVA value will be passed to the default shell to be expanded
before being used.  That's an invalid assumption.

> The problem is that makefiles sometimes do non-trivial processing of
> make variables before using them in recipes, where they (hopefully)
> get expanded by the shell. This is very common in EPICS. If this
> processing is written in a way that, for instance, expects an absolute
> path to start with a '/' then this processing will fail even though
> the shell will expand it to one.

Another case is if the value is used in the default shell in single
quotes thereby disabling the shell's tilde expansion.

> (*) Interestingly, neither my spell checker nor Webster knows this
> word, but I've read it many, many times in English texts so it can't
> be completely wrong, or can it?

Same for me. :-)  I'm sure it's correct.  Maybe it's mostly used in
engineering, science, or technical circles, and it hasn't hit the
mainstream free English dictionaries (yet?).  I bet the OED has it, but
I don't have access to that; it costs an arm and a leg.

Regards,

Lewis

Experimental Physics and Industrial Control System

Experimental Physics and
Industrial Control System