labs - return long integer absolute value

Syntax	#include <stdlib.h> long int labs(long int j);
Description	labs() computes the absolute value of an integer j of type long.
Return val.	Absolute value of the long integer j if successful.
Notes	The absolute value of the negative integer with the largest magnitude is not representable. If a negative number with the highest magnitude (-231) is specified as the argument j, the program will terminate with an error.
See also	abs(), cabs(), stdlib.h.