**NAME**

log10, log10f, log10l - base-10 logarithmic function

**SYNOPSIS**

**#include** **<math.h>**
**double** **log10(double** __x__**);**
**float** **log10f(float** __x__**);**
**long** **double** **log10l(long** **double** __x__**);**
Link with __-lm__.
Feature Test Macro Requirements for glibc (see **feature_test_macros**(7)):
**log10f**(), **log10l**(): _BSD_SOURCE || _SVID_SOURCE || _XOPEN_SOURCE >= 600
|| _ISOC99_SOURCE; or __cc__ __-std=c99__

**DESCRIPTION**

The **log10**() function returns the base 10 logarithm of __x__.

**RETURN** **VALUE**

On success, these functions return the base 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).

**CONFORMING** **TO**

C99, POSIX.1-2001. The variant returning __double__ also conforms to SVr4,
4.3BSD, C89.

**SEE ALSO**

**cbrt**(3), **clog10**(3), **exp10**(3), **sqrt**(3)

**COLOPHON**

This page is part of release 3.24 of the Linux __man-pages__ project. A
description of the project, and information about reporting bugs, can
be found at http://www.kernel.org/doc/man-pages/.
2008-08-05