scalbn (3)  Linux Manuals
NAME
scalbn, scalbnf, scalbnl, scalbln, scalblnf, scalblnl  multiply floatingpoint number by integral power of radix
SYNOPSIS
#include <math.h>
double scalbln(double x, long exp);
float scalblnf(float x, long exp);
long double scalblnl(long double x, long exp);
double scalbn(double x, int exp);
float scalbnf(float x, int exp);
long double scalbnl(long double x, int exp);
Link with lm.
Feature Test Macro Requirements for glibc (see feature_test_macros(7)):
scalbln(), scalblnf(), scalblnl():

_ISOC99_SOURCE  _POSIX_C_SOURCE >= 200112L
 /* Since glibc 2.19: */ _DEFAULT_SOURCE
scalbn(), scalbnf(), scalbnl():

_ISOC99_SOURCE  _POSIX_C_SOURCE >= 200112L
 /* Since glibc 2.19: */ _DEFAULT_SOURCE
 /* Glibc versions <= 2.19: */ _BSD_SOURCE  _SVID_SOURCE
DESCRIPTION
These functions multiply their first argument x by FLT_RADIX (probably 2) to the power of exp, that is:
x * FLT_RADIX ** exp
The definition of FLT_RADIX can be obtained by including <float.h>.
RETURN VALUE
On success, these functions return x * FLT_RADIX ** exp.If x is a NaN, a NaN is returned.
If x is positive infinity (negative infinity), positive infinity (negative infinity) is returned.
If x is +0 (0), +0 (0) is returned.
If the result overflows, a range error occurs, and the functions return HUGE_VAL, HUGE_VALF, or HUGE_VALL, respectively, with a sign the same as x.
If the result underflows, a range error occurs, and the functions return zero, with a sign the same as x.
ERRORS
See math_error(7) for information on how to determine whether an error has occurred when calling these functions.The following errors can occur:
 Range error, overflow
 An overflow floatingpoint exception (FE_OVERFLOW) is raised.
 Range error, underflow
 errno is set to ERANGE. An underflow floatingpoint exception (FE_UNDERFLOW) is raised.
VERSIONS
These functions first appeared in glibc in version 2.1.ATTRIBUTES
For an explanation of the terms used in this section, see attributes(7).Interface  Attribute  Value 
scalbn(),
scalbnf(),
scalbnl(),
scalbln(), scalblnf(), scalblnl()  Thread safety  MTSafe 
CONFORMING TO
C99, POSIX.12001, POSIX.12008.NOTES
These functions differ from the obsolete functions described in scalb(3) in the type of their second argument. The functions described on this page have a second argument of an integral type, while those in scalb(3) have a second argument of type double.If FLT_RADIX equals 2 (which is usual), then scalbn() is equivalent to ldexp(3).
BUGS
Before glibc 2.20, these functions did not set errno for range errors.COLOPHON
This page is part of release 5.10 of the Linux manpages 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/manpages/.