Do: using the identity operator (===), which doesn’t make any implicit type conversions when the compared variables have different types. Don’t: You should probably be cautious about using these two methods for your specific needs: Any string which isn’t the empty string will evaluate to true by using them. Although they’re the cleanest methods I can think of concerning … Read more
You can try Wolfram Alpha as in this example based on your input: http://www.wolframalpha.com/input/?i=((A%20OR%20B)%20AND%20(NOT%20B%20AND%20C)%20OR%20C)&t=crmtb01&f=rc
try grep returns true if it finds the search target, and false if it doesn’t. So NOT false == true. if evaluation in shells are designed to be very flexible, and many times doesn’t require chains of commands (as you have written). Also, looking at your code as is, your use of the $( … ) form of cmd-substitution is to be commended, but think about … Read more
There’s no performance difference, as they compile to the same bytecode: Stylistically, I try to avoid not x is y, a human reader might misunderstand it as (not x) is y. If I write x is not y then there is no ambiguity.
You can try Wolfram Alpha as in this example based on your input: http://www.wolframalpha.com/input/?i=((A%20OR%20B)%20AND%20(NOT%20B%20AND%20C)%20OR%20C)&t=crmtb01&f=rc
You can try Wolfram Alpha as in this example based on your input: http://www.wolframalpha.com/input/?i=((A%20OR%20B)%20AND%20(NOT%20B%20AND%20C)%20OR%20C)&t=crmtb01&f=rc