Originally Posted by
tindala
ok,
then for this feature test macro:
acct(): _BSD_SOURCE || (_XOPEN_SOURCE && _XOPEN_SOURCE < 500)
i have answered the following:
"
As to the first question, if _XOPEN_SOURCE is not defined, then it will be treated as 0 when compared to a number, which would unexpectedly make that condition true. Thus you check that it is defined, and then that it has a value less than 500.
"
then it will be treated as 0 when compared to a number , the test is done in this condition: _XOPEN_SOURCE < 500 , then how do i test that it has a value less than 500 ?