.\" Copyright 1993 David Metcalfe (david@prism.demon.co.uk)
.\" and Copyright 2008, Linux Foundation, written by Michael Kerrisk
.\"     <mtk.manpages@gmail.com>
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.\" References consulted:
.\"     Linux libc source code
.\"     Lewine's _POSIX Programmer's Guide_ (O'Reilly & Associates, 1991)
.\"     386BSD man pages
.\" Modified 1993-07-24 by Rik Faith (faith@cs.unc.edu)
.\" Modified 1995-08-14 by Arnt Gulbrandsen <agulbra@troll.no>
.\" Modified 2002-07-27 by Walter Harms
.\" 	(walter.harms@informatik.uni-oldenburg.de)
.\"
.TH LOG10 3  2017-09-15  "" "Linux Programmer's Manual"
.SH NAME
log10, log10f, log10l \-  base-10 logarithmic function
.SH SYNOPSIS
.nf
.B #include <math.h>
.PP
.BI "double log10(double " x );
.BI "float log10f(float " x );
.BI "long double log10l(long double " x );
.fi
.PP
Link with \fI\-lm\fP.
.PP
.in -4n
Feature Test Macro Requirements for glibc (see
.BR feature_test_macros (7)):
.in
.PP
.ad l
.BR log10f (),
.BR log10l ():
.RS 4
_ISOC99_SOURCE || _POSIX_C_SOURCE\ >=\ 200112L
    || /* Since glibc 2.19: */ _DEFAULT_SOURCE
    || /* Glibc versions <= 2.19: */ _BSD_SOURCE || _SVID_SOURCE
.RE
.ad
.SH DESCRIPTION
These functions return the base 10 logarithm of
.IR x .
.SH RETURN VALUE
On success, these functions return the base 10 logarithm of
.IR x .
.PP
For special cases, including where
.I x
is 0, 1, negative, infinity, or NaN, see
.BR log (3).
.SH ERRORS
See
.BR math_error (7)
for information on how to determine whether an error has occurred
when calling these functions.
.PP
For a discussion of the errors that can occur for these functions, see
.BR log (3).
.SH ATTRIBUTES
For an explanation of the terms used in this section, see
.BR attributes (7).
.TS
allbox;
lbw28 lb lb
l l l.
Interface	Attribute	Value
T{
.BR log10 (),
.BR log10f (),
.BR log10l ()
T}	Thread safety	MT-Safe
.TE
.SH CONFORMING TO
C99, POSIX.1-2001, POSIX.1-2008.
.PP
The variant returning
.I double
also conforms to
SVr4, 4.3BSD, C89.
.SH SEE ALSO
.BR cbrt (3),
.BR clog10 (3),
.BR exp10 (3),
.BR log (3),
.BR log2 (3),
.BR sqrt (3)
.SH COLOPHON
This page is part of release 4.16 of the Linux
.I man-pages
project.
A description of the project,
information about reporting bugs,
and the latest version of this page,
can be found at
\%https://www.kernel.org/doc/man\-pages/.