Toan Pham wrote: > I do not know where to ask this question perhaps this mailing list is > best because it had to do with c complilation. > > I would like to set up a make target dynamicly. for example > > when one issue command: make sda1 > it auto compile and install to a mount point @ /mnt/sda1 > > similiarly: make sda2 would compile and install to /mnt/sda2 > > > i know that in a makefile one can accomplish this by setting up two targets, ie. > > sda1: > make all > mount /dev/sda1 /mnt/sda1 > cp releases/* /mnt/sda1 > umount /mnt/sda1 > > sda2: > make all > mount /dev/sda1 /mnt/sda2 > cp releases/* /mnt/sda2 > umount /mnt/sda2 > > > i am curious if we can simplify everything by having a make target > like this when no matches found > > $param1: > make all > mount /dev/sda1 /mnt/$param1 > cp releases/* /mnt/$param1 > umount /mnt/$param1 You could use a pattern rule, e.g.: sda%: make all mount /dev/$@ /mnt/$@ cp releases/* /mnt/$@ umount /mnt/$@ But that's really abusing make; it's better to use variables for this, e.g.: DISC = sda1 install: make all mount /dev/$(DISC) /mnt/$(DISC) cp releases/* /mnt/$(DISC) umount /mnt/$(DISC) and use e.g.: make install DISC=sda1 Beyond that: 1. Don't use "make" in commands; use $(MAKE) instead. This will work if your make program is actually called e.g. gmake, make-3.81, etc. Also, if you use "make -n", $(MAKE) will perform a recursive "make -n" rather than just printing the "make" command. 1a. But only invoke $(MAKE) explicitly if you need to force a particular sequence. It's usually preferable to list the target as a prerequisite, e.g.: install: all rather than: install: $(MAKE) all 2. Use $(INSTALL) rather than "cp". "install" will replace files atomically, while "cp" overwrites the destination in-place. This fails if the destination is an executable which is in-use, and can cause problems due to parallel builds attempting to proceed with an incomplete source file. 3. "phony" targets shouldn't be over-used. Their behaviour can be non-intuitive with respect to parallel builds, and executing commands unconditionally becomes a nuisance once a project gets large. -- Glynn Clements <glynn@xxxxxxxxxxxxxxxxxx> -- To unsubscribe from this list: send the line "unsubscribe linux-c-programming" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
