在bash,等于和双等测试运算符之间有什么区别？
[[ "a" = "a" ]] && echo equal || echo not-equal
[[ "a" == "a" ]] && echo equal || echo not-equal
[[ "a" = "b" ]] && echo equal || echo not-equal
[[ "a" == "b" ]] && echo equal || echo not-equal
结果是:
equal
equal
not-equal
not-equal