./configure script prototype

I've started writing up a configuration script to move some of the logic 
out of the Makefile and make it a bit easier to enable/disable certain 
stuff.

I'm not exactly fluent in what sh flavours accept what syntax and the 
uname -m output is a bit of a mystery for some architectures (PowerPC, 
notably) so the SHA1 method selection stuff might not work.

Thoughts? Comments? Patches?

-- 
Andreas Ericsson                   andreas.ericsson@op5.se
OP5 AB                             www.op5.se
Tel: +46 8-230225                  Fax: +46 8-230231

Andreas Ericsson wrote:

I've started writing up a configuration script to move some of the logic 
out of the Makefile and make it a bit easier to enable/disable certain 
stuff.

I'm not exactly fluent in what sh flavours accept what syntax and the 
uname -m output is a bit of a mystery for some architectures (PowerPC, 
notably) so the SHA1 method selection stuff might not work.

Thoughts? Comments? Patches?

Attachments? ;)

-- 
Andreas Ericsson                   andreas.ericsson@op5.se
OP5 AB                             www.op5.se
Tel: +46 8-230225                  Fax: +46 8-230231

Dear diary, on Mon, Nov 14, 2005 at 01:18:52PM CET, I got a letter
where Andreas Ericsson [off-list ref] said that...

		--prefix=*)
			prefix=${1##*=}

Aren't those heavy bashisms?

-- 
				Petr "Pasky" Baudis
Stuff: http://pasky.or.cz/
VI has two modes: the one in which it beeps and the one in which
it doesn't.

Petr Baudis wrote:

Dear diary, on Mon, Nov 14, 2005 at 01:18:52PM CET, I got a letter
where Andreas Ericsson [off-list ref] said that...

quoted

	--prefix=*)
		prefix=${1##*=}

Aren't those heavy bashisms?

Dunno. I only know bash-scripting, really. I'll replace them with some 
sed thing instead.

-- 
Andreas Ericsson                   andreas.ericsson@op5.se
OP5 AB                             www.op5.se
Tel: +46 8-230225                  Fax: +46 8-230231

On Mon, Nov 14, 2005 at 03:32:13PM +0100, Andreas Ericsson wrote:

Dunno. I only know bash-scripting, really. I'll replace them with
some sed thing instead.

For some people /bin/sh != /bin/bash so you probably want "!/bin/bash"
instead.

Chris Wedgwood wrote:

On Mon, Nov 14, 2005 at 03:32:13PM +0100, Andreas Ericsson wrote:

quoted

Dunno. I only know bash-scripting, really. I'll replace them with
some sed thing instead.

For some people /bin/sh != /bin/bash so you probably want "!/bin/bash"
instead.

Ach no. The configure script really needs to be portable. POSIX (or SUS 
or some such) define a minimum syntax that any shell must support when 
invoked as /bin/sh.

-- 
Andreas Ericsson                   andreas.ericsson@op5.se
OP5 AB                             www.op5.se
Tel: +46 8-230225                  Fax: +46 8-230231

On Mon, Nov 14, 2005 at 02:29:56PM +0100, Petr Baudis wrote:
| Dear diary, on Mon, Nov 14, 2005 at 01:18:52PM CET, I got a letter
| where Andreas Ericsson [off-list ref] said that...
| > 		--prefix=*)
| > 			prefix=${1##*=}
| 
| Aren't those heavy bashisms?

As far as I know, it should be supported by a POSIX 'sh'[1]:

---8<---
${parameter##word}

Remove Largest Prefix Pattern. The word shall be expanded to produce a
pattern. The parameter expansion shall then result in parameter, with
the largest portion of the prefix matched by the pattern deleted.
---8<---

Whether other shells support it or not... I don't know.

Cheers,
Ferdy

[1] http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html

-- 
Fernando J. Pereda Garcimartin
Gentoo Developer (Alpha,net-mail,mutt,git)
20BB BDC3 761A 4781 E6ED  ED0B 0A48 5B0C 60BD 28D4

On Mon, Nov 14, 2005 at 05:11:58PM +0100, Andreas Ericsson wrote:

Ach no. The configure script really needs to be portable. POSIX (or
SUS or some such) define a minimum syntax that any shell must
support when invoked as /bin/sh.

Then bashism need to go away and it should be test with
dash/ash/whatever.

On Mon, Nov 14, 2005 at 02:29:56PM +0100, Petr Baudis wrote:

Dear diary, on Mon, Nov 14, 2005 at 01:18:52PM CET, I got a letter
where Andreas Ericsson [off-list ref] said that...

quoted

		--prefix=*)
			prefix=${1##*=}

	${i# and ${i% are POSIX, iirc.

Joel

-- 

Life's Little Instruction Book #197

	"Don't forget, a person's greatest emotional need is to 
	 feel appreciated."

Joel Becker
Principal Software Developer
Oracle
E-mail: joel.becker@oracle.com
Phone: (650) 506-8127

On Mon, 14 Nov 2005, Joel Becker wrote:

On Mon, Nov 14, 2005 at 02:29:56PM +0100, Petr Baudis wrote:

quoted

Dear diary, on Mon, Nov 14, 2005 at 01:18:52PM CET, I got a letter
where Andreas Ericsson [off-list ref] said that...

quoted

		--prefix=*)
			prefix=${1##*=}

	${i# and ${i% are POSIX, iirc.

They may be in POSIX, but they sure as h*ll aren't portable.

There's a _lot_ of machines out there that don't do POSIX, just because 
those "newfangled" things are so complicated.

Also, even in POSIX, there's tons of different substandards, and you might 
follow one but not the other. 

Finally, even if somebody is certified, they can very well be certified 
with "exceptions", so if they claim POSIX it doesn't necessarily mean that 
they follow all of it.

If you want to do a "configure" script (and I'm not sure it's worth it), 
you should cater to the lowest common denominator for it to be meaningful. 
What the hell that would be, I have no idea, since if you ever want to run 
on native Windows, it won't even be traditional shell. But traditional 
shell is at least a lot closer to that lowest common denominator than 
POSIX shell is.

That said, most of those ${var...} sequences definitely _are_ very 
traditional, and for all I know, ## may be too.

			Linus

On Mon, Nov 14, 2005 at 10:39:26AM -0800, Linus Torvalds wrote:

quoted

	${i# and ${i% are POSIX, iirc.

They may be in POSIX, but they sure as h*ll aren't portable.

	By POSIX I meant POSIX shell, which is ksh.  That's available on
just about all modern non-free Unices, and we all know bash and zsh are
compatible with it.
	But I had no intention of arguing how portable POSIX is, I was
just trying to describe the minimum breadth of support.  My personal
experience is that these particular variable forms have worked on Linux,
Solaris, AIX, Ultrix, IRIX, and the BSDs for, I dunno, eight to ten
years or so.
	That said, $(echo | sed), or `echo | sed` for even more
backwards portability (I bet $() is about as portable as ${i%}), can be
used to replace the ${i%} forms.

Joel

-- 

"I always thought the hardest questions were those I could not answer.
 Now I know they are the ones I can never ask."
			- Charlie Watkins

Joel Becker
Principal Software Developer
Oracle
E-mail: joel.becker@oracle.com
Phone: (650) 506-8127

Linus Torvalds wrote:

On Mon, 14 Nov 2005, Joel Becker wrote:

quoted

On Mon, Nov 14, 2005 at 02:29:56PM +0100, Petr Baudis wrote:

quoted

Dear diary, on Mon, Nov 14, 2005 at 01:18:52PM CET, I got a letter
where Andreas Ericsson [off-list ref] said that...

quoted

	--prefix=*)
		prefix=${1##*=}

${i# and ${i% are POSIX, iirc.

They may be in POSIX, but they sure as h*ll aren't portable.

A bit funny really. I've already said I'll change them to some sed 
thing, so the last 16 emails on this thread have been purely academic. I 
guess more people than me are bored by mondays.

If you want to do a "configure" script (and I'm not sure it's worth it), 

Perhaps not. I was under the impression that Junio was for it to 
simplify the possible move of binaries to GIT_EXEC_PATH.

-- 
Andreas Ericsson                   andreas.ericsson@op5.se
OP5 AB                             www.op5.se
Tel: +46 8-230225                  Fax: +46 8-230231