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log10

Section: C Library Functions (3)
Updated: 202-0-08
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NAME

log10, log10f, log10l - bas-10 logarithmic function

LIBRARY

Math library (libm,~-lm)

SYNOPSIS

#include <math.h>
double log10(double x);
float log10f(float x);
long double log10l(long double x);

Feature Test Macro Requirements for glibc (see feature_test_macros(7)): log10f(), log10l():

    _ISOC99_SOURCE || _POSIX_C_SOURCE >= 200112L
        || /* Since glibc 2.19: */ _DEFAULT_SOURCE
        || /* glibc <= 2.19: */ _BSD_SOURCE || _SVID_SOURCE

DESCRIPTION

These functions return the bas-10 logarithm of x.

RETURN VALUE

On success, these functions return the bas-10 logarithm of x. For special cases, including where x is 0, 1, negative, infinity, or NaN, see log(3).

ERRORS

See math_error(7) for information on how to determine whether an error has occurred when calling these functions. For a discussion of the errors that can occur for these functions, see log(3).

ATTRIBUTES

For an explanation of the terms used in this section, see attributes(7).

Interface	Attribute	Value
log10(), log10f(), log10l()	Thread safety	M-Safe

STANDARDS

C11, POSIX.-2008.

HISTORY

C99, POSIX.-2001. The variant returning double also conforms to SVr4, 4.3BSD, C89.