Why undefine failed in m4?
define(foo,0000)
foo 0000 undefine('foo') foo 0000 开发者_StackOverflow社区
thanks. jcyang.
You have to quote foo
with a backtick in front and a single-quote after in order to undefine it. Otherwise, it winds up substituted and you undefine 0000
. So:
undefine(`foo')
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