LOG10(3) Library Functions Manual LOG10(3)

log10 — base 10 logarithm function

#include <math.h>

double log10(double x);

The log10() function computes the base 10 logarithm of x , log 10 ( x ). The value of x must be positive.

An application wishing to check for error situations should set errno to 0 before calling log10(). If errno is non-zero on return, or the return value is NaN, an error has occurred.

Upon successful completion, log10() returns the base 10 logarithm of x .

If x is NaN, NaN is returned and errno may be set to [EDOM].

If x is less than 0, -HUGE_VAL or NaN is returned, and errno is set to [EDOM].

If x is 0, -HUGE_VAL is returned and errno may be set to [ERANGE].

The log10() function will fail if:

The value of x is negative.

The log10() function may fail if:

The value of x is NaN.
The value of x is 0.

No other errors will occur.

None.

None.

None.

isnan(3) , log(3) , pow(3) , <math.h> .

Derived from Issue 1 of the SVID.

February 1997 posix.fail