### NAME

scalbn, scalbnf, scalbnl, scalbln, scalblnf, scalblnl - multiply floating-point number by integral power of radix

### SYNOPSIS

**#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; or
*cc -std=c99* **scalbn**(), **scalbnf**(), **scalbnl**(): _BSD_SOURCE || _SVID_SOURCE || _XOPEN_SOURCE >= 600 || _ISOC99_SOURCE; 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 floating-point exception
(FE_OVERFLOW) is raised.
| |

Range error, underflow | |

An underflow floating-point exception
(FE_UNDERFLOW) is raised.
| |

*errno*.

### VERSIONS

These functions first appeared in glibc in version 2.1.

### CONFORMING TO

C99, POSIX.1-2001.

### 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).

### SEE ALSO

### COLOPHON

This page is part of release 3.23 of the Linux
*man-pages* project.
A description of the project,
and information about reporting bugs,
can be found at
http://www.kernel.org/doc/man-pages/.