man3/log10.3

   1 .\" Copyright 1993 David Metcalfe (david@prism.demon.co.uk)
   2 .\" and Copyright 2008, Linux Foundation, written by Michael Kerrisk
   3 .\"     <mtk.manpages@gmail.com>
   4 .\"
   5 .\" SPDX-License-Identifier: Linux-man-pages-copyleft
   6 .\"
   7 .\" References consulted:
   8 .\"     Linux libc source code
   9 .\"     Lewine's _POSIX Programmer's Guide_ (O'Reilly & Associates, 1991)
  10 .\"     386BSD man pages
  11 .\" Modified 1993-07-24 by Rik Faith (faith@cs.unc.edu)
  12 .\" Modified 1995-08-14 by Arnt Gulbrandsen <agulbra@troll.no>
  13 .\" Modified 2002-07-27 by Walter Harms
  14 .\"     (walter.harms@informatik.uni-oldenburg.de)
  15 .\"
  16 .TH LOG10 3  2021-03-22  "" "Linux Programmer's Manual"
  17 .SH NAME
  18 log10, log10f, log10l \-  base-10 logarithmic function
  19 .SH LIBRARY
  20 Math library
  21 .RI ( libm ", " \-lm )
  22 .SH SYNOPSIS
  23 .nf
  24 .B #include <math.h>
  25 .PP
  26 .BI "double log10(double " x );
  27 .BI "float log10f(float " x );
  28 .BI "long double log10l(long double " x );
  29 .fi
  30 .PP
  31 .RS -4
  32 Feature Test Macro Requirements for glibc (see
  33 .BR feature_test_macros (7)):
  34 .RE
  35 .PP
  36 .BR log10f (),
  37 .BR log10l ():
  38 .nf
  39     _ISOC99_SOURCE || _POSIX_C_SOURCE >= 200112L
  40         || /* Since glibc 2.19: */ _DEFAULT_SOURCE
  41         || /* Glibc <= 2.19: */ _BSD_SOURCE || _SVID_SOURCE
  42 .fi
  43 .SH DESCRIPTION
  44 These functions return the base 10 logarithm of
  45 .IR x .
  46 .SH RETURN VALUE
  47 On success, these functions return the base 10 logarithm of
  48 .IR x .
  49 .PP
  50 For special cases, including where
  51 .I x
  52 is 0, 1, negative, infinity, or NaN, see
  53 .BR log (3).
  54 .SH ERRORS
  55 See
  56 .BR math_error (7)
  57 for information on how to determine whether an error has occurred
  58 when calling these functions.
  59 .PP
  60 For a discussion of the errors that can occur for these functions, see
  61 .BR log (3).
  62 .SH ATTRIBUTES
  63 For an explanation of the terms used in this section, see
  64 .BR attributes (7).
  65 .ad l
  66 .nh
  67 .TS
  68 allbox;
  69 lbx lb lb
  70 l l l.
  71 Interface       Attribute       Value
  72 T{
  73 .BR log10 (),
  74 .BR log10f (),
  75 .BR log10l ()
  76 T}      Thread safety   MT-Safe
  77 .TE
  78 .hy
  79 .ad
  80 .sp 1
  81 .SH CONFORMING TO
  82 C99, POSIX.1-2001, POSIX.1-2008.
  83 .PP
  84 The variant returning
  85 .I double
  86 also conforms to
  87 SVr4, 4.3BSD, C89.
  88 .SH SEE ALSO
  89 .BR cbrt (3),
  90 .BR clog10 (3),
  91 .BR exp10 (3),
  92 .BR log (3),
  93 .BR log2 (3),
  94 .BR sqrt (3)