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 labs(long j);
13       long long llabs(long long 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():
22           _ISOC99_SOURCE || _POSIX_C_SOURCE >= 200112L
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DESCRIPTION

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

31       Returns the absolute value of the integer argument, of the  appropriate
32       integer type for the function.
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ATTRIBUTES

35       For  an  explanation  of  the  terms  used  in  this  section,  see at‐
36       tributes(7).
37
38       ┌────────────────────────────────────────────┬───────────────┬─────────┐
39       │Interface                                   │ Attribute     │ Value   │
40       ├────────────────────────────────────────────┼───────────────┼─────────┤
41       │abs(), labs(), llabs(), imaxabs()           │ Thread safety │ MT-Safe │
42       └────────────────────────────────────────────┴───────────────┴─────────┘
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CONFORMING TO

45       POSIX.1-2001, POSIX.1-2008, C99, SVr4, 4.3BSD.  C89 only  includes  the
46       abs()  and  labs()  functions; the functions llabs() and imaxabs() were
47       added in C99.
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NOTES

50       Trying to take the absolute value of the most negative integer  is  not
51       defined.
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53       The llabs() function is included in glibc since version 2.0.  The imax‐
54       abs() function is included in glibc since version 2.1.1.
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56       For  llabs()  to  be  declared,  it  may   be   necessary   to   define
57       _ISOC99_SOURCE  or  _ISOC9X_SOURCE  (depending on the version of glibc)
58       before including any standard headers.
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60       By default, GCC handles abs(), labs(), and (since GCC 3.0) llabs()  and
61       imaxabs() as built-in functions.
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SEE ALSO

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

67       This  page  is  part of release 5.13 of the Linux man-pages project.  A
68       description of the project, information about reporting bugs,  and  the
69       latest     version     of     this    page,    can    be    found    at
70       https://www.kernel.org/doc/man-pages/.
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74GNU                               2021-03-22                            ABS(3)
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