scalbln (3)
Leading comments
Copyright 2004 Andries Brouwer <aeb@cwi.nl>. and Copyright 2008, Linux Foundation, written by Michael Kerrisk <mtk.manpages@gmail.com> %%%LICENSE_START(VERBATIM) Permission is granted to make and distribute verbatim copies of this manual provided the copyright notice and this permission notice are preserved on all copies. Permission is granted to copy and distribute modified versions of this manual under the conditions for verbatim copying, provided that the entire resulting derived wor...
NAME
scalbn, scalbnf, scalbnl, scalbln, scalblnf, scalblnl  multiply floatingpoint number by integral power of radixSYNOPSIS
#include <math.h>
double scalbln(double x, long int exp);
float scalblnf(float x, long int exp);
long double scalblnl(long double x, long int 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():

_XOPEN_SOURCE >= 600  _ISOC99_SOURCE 
_POSIX_C_SOURCE >= 200112L;
or cc std=c99
scalbn(), scalbnf(), scalbnl():

_BSD_SOURCE  _SVID_SOURCE  _XOPEN_SOURCE >= 600  _ISOC99_SOURCE 
_POSIX_C_SOURCE >= 200112L;
or cc std=c99
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
 An underflow floatingpoint exception (FE_UNDERFLOW) is raised.
These functions do not set errno.
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).