What is the difference between ; and &&

[Matthew Seaman]

On Wed, Jan 07, 2004 at 11:38:58PM +0000, Ceri Davies wrote:
> On Wed, Jan 07, 2004 at 05:36:42PM -0600, Eric F Crist wrote:

> > make depend && make && make install

> [Of course, if the Makefile has it's dependencies correct, then a simple
>  "make install" will achieve the same thing.]

Hmmm... Usually 'make depend' generates a dependency Makefile, which
is .included'ed into the main Makefile on subsequent runs.  That means
that

    make depend ; make all

has a different effect to:

    make depend all

Unless make(1) has been taught to keep tabs on it's included Makefiles
and knows how to re-load them if their modification time changes.  As
I understood it, that was a trick that gmake(1) could do but that BSD
make couldn't.

	Cheers,

	Matthew

-- 
Dr Matthew J Seaman MA, D.Phil.                       26 The Paddocks
                                                      Savill Way
PGP: http://www.infracaninophile.co.uk/pgpkey         Marlow
Tel: +44 1628 476614                                  Bucks., SL7 1TH UK
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