FPCLASSIFY (3) | C library functions | Unix Manual Pages | :man▋
fpclassify, isfinite, isinf, isnan, isnormal - "classify a floating-point number"
.In math.h int fpclassify "real-floating x" int isfinite "real-floating x" int isinf "real-floating x" int isnan "real-floating x" int isnormal "real-floating x"
The fpclassify macro takes an argument of x and returns one of the following manifest constants.
| FP_INFINITE || Indicates that x is an infinite number. |
| FP_NAN || Indicates that x is not a number (NaN). |
| FP_NORMAL || Indicates that x is a normalized number. |
| FP_SUBNORMAL || Indicates that x is a denormalized number. |
| FP_ZERO || Indicates that x is zero (0 or -0). |
The isfinite macro returns a non-zero value if and only if its argument has a finite (zero, subnormal, or normal) value. The isinf, isnan, and isnormal macros return non-zero if and only if x is an infinity, NaN, or a non-zero normalized number, respectively.
The symbol isnanf is provided as an alias to isnan for compatibility, and its use is deprecated. Similarly, finite and finitef are deprecated versions of isfinite.
isgreater(3), math(3), signbit(3)
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