digging through the build system for the hyperledger fabric
distributed ledger technology, and noticed something in the Makefile
i'd never seen before that took me a couple seconds to recognize:
.PHONY: clean
clean: docker-clean unit-test-clean release-clean
-@rm -rf build ||:
.PHONY: clean-all
clean-all: clean gotools-clean dist-clean
-@rm -rf /var/hyperledger/* ||:
i thought, what's with that "||:" at the end of those rm commands,
then it dawned on me that it just means if the command fails, continue
and run the "true" command; in other words, if the rm command fails,
keep going.
but what is the value of that, given the leading "-" for the
command, which i understood to mean the same thing? isn't that
overkill? this question at SO:
https://stackoverflow.com/questions/7772393/gnu-make-run-a-target-after-all-others-regardless-of-failures
has an answer that pretty clearly suggests "||:" is a bit silly when a
leading "-" does the same thing and more obviously?
thoughts?
rday
p.s. in those two cases, even the "-" is superfluous since "rm -rf"
can't fail, even if the file or directory doesn't exist.