- test for a normal value
c99 [ flag... ] file... -lm [ library... ] #include <math.h> int isnormal(real-floating x);
The isnormal() macro determines whether its argument value is normal (neither zero, subnormal, infinite, nor NaN). First, an argument represented in a format wider than its semantic type is converted to its semantic type. Then determination is based on the type of the argument.
The isnormal() macro returns a non-zero value if and only if its argument has a normal value.
No errors are defined.
See attributes(5) for descriptions of the following attributes: