TCLUG Development Archive
[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Re: [TCLUG-DEVEL:98] GNU Make and shell expansions
On Sat, Feb 19, 2000 at 01:02:14PM -0600, John R. Sheets wrote:
> How portable are the shell expansions that GNU Make uses, to other
> implementations of make? I'm referring to these constructs:
>
> CURRENT_DIR=$(shell pwd)
> CURRENT_DIR2=`pwd`
>
> Both forms seem to work fine with GNU make. Are they GNU-specific
> extensions, though?
I've noticed that makes vary widely among platforms as to what
extensions they support. I don't know if there is a POSIX standard for
make.
For example, pattern rules (%.o : %.c) are not part of make as
it was originally written. On the other hand, I think several makes
besides GNU actually support them.
The same for the shell expansion thing. Since that's a feature
that I'm much less familiar with, I don't know whether it's widely
supported or not. But, even if it's a GNU specific thing, it's likely
that it will be eventually picked up by other makes, especially if it
becomes a popular feature.
Writing a makefile that will work with any old vanilla make is
really hard.
Have fun (if at all possible),
--
Its name is Public Opinion. It is held in reverence. It settles everything.
Some think it is the voice of God. Loyalty to petrified opinion never yet
broke a chain or freed a human soul. ---Mark Twain
-- Eric Hopper (hopper@omnifarious.mn.org http://omnifarious.mn.org/~hopper) --
PGP signature