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



 

NAME


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

 

SYNOPSIS


       #include 

       int abs(int j);
       long int labs(long int j);
       long long int llabs(long long int j);

       #include 

       intmax_t imaxabs(intmax_t j);

   Feature Test Macro Requirements for glibc (see feature_test_macros(7)):

       llabs(): _XOPEN_SOURCE >= 600 || _ISOC99_SOURCE; or cc -std=c99

 

DESCRIPTION






       The  abs() function computes the absolute value of the integer argument
       j.  The labs(), llabs() and imaxabs() functions  compute  the  absolute
       value  of  the argument j of the appropriate integer type for the func-
       tion.

 

RETURN VALUE


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

 

CONFORMING TO


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

 

NOTES


       Trying  to  take the absolute value of the most negative integer is not
       defined.

       The llabs() function is included in glibc since version 2.0, but is not
       in  libc5  or libc4.  The imaxabs() function is included in glibc since
       version 2.1.1.

       For  llabs()  to  be  declared,  it  may   be   necessary   to   define
       _ISOC99_SOURCE  or  _ISOC9X_SOURCE  (depending on the version of glibc)
       before including any standard headers.

       GCC handles abs() and labs() as built-in functions.  GCC 3.0 also  han-
       dles llabs() and imaxabs() as built-ins.

 

SEE ALSO


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

 

COLOPHON


       This  page  is  part of release 3.05 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/.



GNU                               2007-07-26                            ABS(3)