c99 [ flag... ] file... –lm [ library... ] #include <math.h> int isfinite(real-floating x);
The isfinite() macro determines whether its argument has a finite value (zero, subnormal, or normal, and not infinite or 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 isfinite() macro returns a non-zero value if and only if its argument has a finite value.
No errors are defined.
See attributes(5) for descriptions of the following attributes: