ABS

Section: Linux Programmer's Manual (3)
Updated: 2014-08-19
Index Return to Main Contents
 

NAME

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

SYNOPSIS

#include <stdlib.h>

int abs(int j);

long int labs(long int j);
long long int llabs(long long int j); #include <inttypes.h> intmax_t imaxabs(intmax_t j);

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

llabs():

_XOPEN_SOURCE >= 600 || _ISOC99_SOURCE || _POSIX_C_SOURCE >= 200112L;
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 function.  

RETURN VALUE

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

ATTRIBUTES

 

Multithreading (see pthreads(7))

The abs(), labs(), llabs(), and imaxabs() functions are thread-safe.  

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. 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 handles llabs() and imaxabs() as built-ins.  

SEE ALSO

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


 

Index

NAME
SYNOPSIS
DESCRIPTION
RETURN VALUE
ATTRIBUTES
Multithreading (see pthreads(7))
CONFORMING TO
NOTES
SEE ALSO

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Time: 02:55:17 GMT, September 18, 2014