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

6       abs, labs, llabs, imaxabs - compute the absolute value of an integer
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SYNOPSIS

9       #include <stdlib.h>
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11       int abs(int j);
12       long int labs(long int j);
13       long long int llabs(long long int j);
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15       #include <inttypes.h>
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17       intmax_t imaxabs(intmax_t j);
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19   Feature Test Macro Requirements for glibc (see feature_test_macros(7)):
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21       llabs(): _XOPEN_SOURCE >= 600 || _ISOC99_SOURCE; or cc -std=c99
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DESCRIPTION

24       The  abs() function computes the absolute value of the integer argument
25       j.  The labs(), llabs() and imaxabs() functions  compute  the  absolute
26       value  of  the argument j of the appropriate integer type for the func‐
27       tion.
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RETURN VALUE

30       Returns the absolute value of the integer argument, of the  appropriate
31       integer type for the function.
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CONFORMING TO

34       SVr4,  POSIX.1-2001,  4.3BSD,  C99.   C89  only  includes the abs() and
35       labs() functions; the functions llabs() and  imaxabs()  were  added  in
36       C99.
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NOTES

39       Trying  to  take the absolute value of the most negative integer is not
40       defined.
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42       The llabs() function is included in glibc since version 2.0, but is not
43       in  libc5  or libc4.  The imaxabs() function is included in glibc since
44       version 2.1.1.
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46       For  llabs()  to  be  declared,  it  may   be   necessary   to   define
47       _ISOC99_SOURCE  or  _ISOC9X_SOURCE  (depending on the version of glibc)
48       before including any standard headers.
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50       GCC handles abs() and labs() as built-in functions.  GCC 3.0 also  han‐
51       dles llabs() and imaxabs() as built-ins.
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SEE ALSO

54       cabs(3), ceil(3), fabs(3), floor(3), rint(3)
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COLOPHON

57       This  page  is  part of release 3.25 of the Linux man-pages project.  A
58       description of the project, and information about reporting  bugs,  can
59       be found at http://www.kernel.org/doc/man-pages/.
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63GNU                               2007-07-26                            ABS(3)
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