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'\" t
.\" Copyright, the authors of the Linux man-pages project
.\"
.\" SPDX-License-Identifier: Linux-man-pages-copyleft
.\"
.TH log10 3 2025-05-17 "Linux man-pages (unreleased)"
.SH NAME
log10, log10f, log10l \- base-10 logarithmic function
.SH LIBRARY
Math library
.RI ( libm ,\~ \-lm )
.SH SYNOPSIS
.nf
.B #include <math.h>
.P
.BI "double log10(double " x );
.BI "float log10f(float " x );
.BI "long double log10l(long double " x );
.fi
.P
.RS -4
Feature Test Macro Requirements for glibc (see
.BR feature_test_macros (7)):
.RE
.P
.BR log10f (),
.BR log10l ():
.nf
_ISOC99_SOURCE || _POSIX_C_SOURCE >= 200112L
|| /* Since glibc 2.19: */ _DEFAULT_SOURCE
|| /* glibc <= 2.19: */ _BSD_SOURCE || _SVID_SOURCE
.fi
.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 .
.P
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.
.P
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;
lbx lb lb
l l l.
Interface Attribute Value
T{
.na
.nh
.BR log10 (),
.BR log10f (),
.BR log10l ()
T} Thread safety MT-Safe
.TE
.SH STANDARDS
C11, POSIX.1-2008.
.SH HISTORY
C99, POSIX.1-2001.
.P
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)
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