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scalb(3) — Linux manual page

NAME \|LIBRARY \|SYNOPSIS \|DESCRIPTION \|RETURN VALUE \|ERRORS \|ATTRIBUTES \|STANDARDS \|HISTORY \|BUGS \|SEE ALSO \|COLOPHON

scalb(3)                 Library Functions Manualscalb(3)

NAME top

       scalb, scalbf, scalbl - scale by an integer power of radix       (OBSOLETE)

LIBRARY top

       Math library (libm,-lm)

SYNOPSIS top

#include <math.h>[[deprecated]] double scalb(doublex, doublee);[[deprecated]] float scalbf(floatx, floate);[[deprecated]] long double scalbl(long doublex, long doublee);   Feature Test Macro Requirements for glibc (seefeature_test_macros(7)):scalb():           _XOPEN_SOURCE >= 500               || /* Since glibc 2.19: */ _DEFAULT_SOURCE               || /* glibc <= 2.19: */ _BSD_SOURCE || _SVID_SOURCEscalbf(),scalbl():           _XOPEN_SOURCE >= 600               || /* Since glibc 2.19: */ _DEFAULT_SOURCE               || /* glibc <= 2.19: */ _BSD_SOURCE || _SVID_SOURCE

DESCRIPTION top

       These functions multiply their first argumentx byFLT_RADIX       (probably 2) to the power ofe, that is:           x * FLT_RADIX ** e       The definition ofFLT_RADIXcan be obtained by including<float.h>.

RETURN VALUE top

       On success, these functions returnx *FLT_RADIX**e.       Ifx ore is a NaN, a NaN is returned.       Ifx is positive infinity (negative infinity), ande is not       negative infinity, positive infinity (negative infinity) is       returned.       Ifx is +0 (-0), ande is not positive infinity, +0 (-0) is       returned.       Ifx is zero, ande is positive infinity, a domain error occurs,       and a NaN is returned.       Ifx is an infinity, ande is negative infinity, a domain error       occurs, and a NaN is returned.       If the result overflows, a range error occurs, and the functions       returnHUGE_VAL,HUGE_VALF, orHUGE_VALL, respectively, with a       sign the same asx.       If the result underflows, a range error occurs, and the functions       return zero, with a sign the same asx.

ERRORS top

       Seemath_error(7) for information on how to determine whether an       error has occurred when calling these functions.       The following errors can occur:       Domain error:x is 0, ande is positive infinity, orx is positive       infinity ande is negative infinity and the other argument is not       a NaNerrno is set toEDOM.  An invalid floating-point exception              (FE_INVALID) is raised.       Range error, overflowerrno is set toERANGE.  An overflow floating-point              exception (FE_OVERFLOW) is raised.       Range error, underflowerrno is set toERANGE.  An underflow floating-point              exception (FE_UNDERFLOW) is raised.

ATTRIBUTES top

       For an explanation of the terms used in this section, seeattributes(7).       ┌──────────────────────────────────────┬───────────────┬─────────┐       │Interface│Attribute│Value│       ├──────────────────────────────────────┼───────────────┼─────────┤       │scalb(),scalbf(),scalbl()          │ Thread safety │ MT-Safe │       └──────────────────────────────────────┴───────────────┴─────────┘

STANDARDS top

       None.

HISTORY top

scalb()              4.3BSD.  Obsolescent in POSIX.1-2001; Removed in              POSIX.1-2008, recommending the use ofscalbln(3),scalblnf(3), orscalblnl(3) instead.

BUGS top

       Before glibc 2.20, these functions did not seterrno for domain       and range errors.

COLOPHON top

       This page is part of theman-pages (Linux kernel and C library       user-space interface documentation) project.  Information about       the project can be found at        ⟨https://www.kernel.org/doc/man-pages/⟩.  If you have a bug report       for this manual page, see       ⟨https://git.kernel.org/pub/scm/docs/man-pages/man-pages.git/tree/CONTRIBUTING⟩.       This page was obtained from the tarball man-pages-6.15.tar.gz       fetched from       ⟨https://mirrors.edge.kernel.org/pub/linux/docs/man-pages/⟩ on       2025-08-11.  If you discover any rendering problems in this HTML       version of the page, or you believe there is a better or more up-       to-date source for the page, or you have corrections or       improvements to the information in this COLOPHON (which isnot       part of the original manual page), send a mail to       man-pages@man7.orgLinux man-pages 6.15            2025-07-19scalb(3)

Pages that refer to this page:scalbln(3), significand(3)

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