1MODF(3)                    Linux Programmer's Manual                   MODF(3)
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NAME

6       modf, modff, modfl - extract signed integral and fractional values from
7       floating-point number
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SYNOPSIS

10       #include <math.h>
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12       double modf(double x, double *iptr);
13       float modff(float x, float *iptr);
14       long double modfl(long double x, long double *iptr);
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16       Link with -lm.
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18   Feature Test Macro Requirements for glibc (see feature_test_macros(7)):
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20       modff(), modfl():
21           _ISOC99_SOURCE || _POSIX_C_SOURCE >= 200112L
22               || /* Since glibc 2.19: */ _DEFAULT_SOURCE
23               || /* Glibc <= 2.19: */ _BSD_SOURCE || _SVID_SOURCE
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DESCRIPTION

26       These functions break the argument x into an integral part and a  frac‐
27       tional  part,  each of which has the same sign as x.  The integral part
28       is stored in the location pointed to by iptr.
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RETURN VALUE

31       These functions return the fractional part of x.
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33       If x is a NaN, a NaN is returned, and *iptr is set to a NaN.
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35       If x is positive infinity (negative infinity), +0 (-0) is returned, and
36       *iptr is set to positive infinity (negative infinity).
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ERRORS

39       No errors occur.
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ATTRIBUTES

42       For  an  explanation  of  the  terms  used  in  this  section,  see at‐
43       tributes(7).
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45       ┌────────────────────────────────────────────┬───────────────┬─────────┐
46       │Interface                                   │ Attribute     │ Value   │
47       ├────────────────────────────────────────────┼───────────────┼─────────┤
48       │modf(), modff(), modfl()                    │ Thread safety │ MT-Safe │
49       └────────────────────────────────────────────┴───────────────┴─────────┘
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CONFORMING TO

52       C99, POSIX.1-2001, POSIX.1-2008.
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54       The variant returning double also conforms to SVr4, 4.3BSD, C89.
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SEE ALSO

57       frexp(3), ldexp(3)
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COLOPHON

60       This page is part of release 5.13 of the Linux  man-pages  project.   A
61       description  of  the project, information about reporting bugs, and the
62       latest    version    of    this    page,    can     be     found     at
63       https://www.kernel.org/doc/man-pages/.
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67                                  2021-03-22                           MODF(3)
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