Make :- pattern matching and dependency checking

[T.Day at ucl-cs.UUCP]

From: Tim Day <T.Day at uk.ac.ucl.cs>

# Consider a ``make setup'' and then a ``make demo'' using this makefile...

setup:		
		touch sea.h
		touch big.fish.c
		rm -f *.o

%.fish.o:	sea.h %.fish.c


demo:		
		$(MAKE) big.fish.o
		touch sea.h
		$(MAKE) big.fish.o


# I'd expect updating ``sea.h'' to force a remake of big.fish.o.
# In fact it only makes big.fish.o once, then says ``big.fish.o is up to date''.
# Obviously pattern matching rules aren't all I thought they were.
# Can anyone enlighten me as to how to achieve this sort of effect, without
# resorting to something like :
# big.fish.o small.fish.o fat.fish.o blow.fish.o: 	sea.h
# ?

# Thanks
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Tim Day                            | Meet every second in life as challenge;
Department of Photogrammetry       | Respond fully to whatever happens
UCL, Gower St., London  WC1E 6BT   |  without anxiety, or complaint, or clinging
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