Added source

examples/get_sign.c

@@ -184,6 +184,7 @@ int main()
 //
 // [your answer here]
 // In bash exit code 255 means "Exit status out of range" and it says "exit takes only integer args in the range 0 - 255". The result should have been -1 but it is out of range for bash, so that is why I didn't get the expected result.
+// Source: https://tldp.org/LDP/abs/html/exitcodes.html
 //
 // D) Debugging
 //