- jessie 3.16.56-1+deb8u1
NAME¶abs - return absolute value of an argument
the value. If it is unsigned type, it is converted to signed type first. char is treated as if it was signed (regardless of whether it really is) but the macro's return type is preserved as char.
RETURN¶an absolute value of x.
|May 2018||Kernel Hackers Manual 3.16|