NAME

labs, llabs — return a long integer absolute value

SYNOPSIS

#include <stdlib.h>

long labs(long i);
long long llabs(long long i);


DESCRIPTION

^[CX] The functionality described on this reference page is aligned with the ISO C standard. Any conflict between the requirements described here and the ISO C standard is unintentional. This volume of POSIX.1-2024 defers to the ISO C standard.

The labs() function shall compute the absolute value of the long integer operand i. The llabs() function shall compute the absolute value of the long long integer operand i. If the result cannot be represented, the behavior is undefined.

RETURN VALUE

The labs() function shall return the absolute value of the long integer operand.

The llabs() function shall return the absolute value of the long long integer operand.

ERRORS

No errors are defined.

EXAMPLES

None.

APPLICATION USAGE

Since POSIX.1 requires a two's complement representation of long and long long, the absolute value of the negative integers with the largest magnitude {LONG_MIN} and {LLONG_MIN} are not representable, thus labs(LONG_MIN) and llabs(LLONG_MIN) are undefined.

RATIONALE

None.

FUTURE DIRECTIONS

None.

SEE ALSO

abs

XBD <stdlib.h>

CHANGE HISTORY

First released in Issue 4. Derived from the ISO C standard.

Issue 6

The llabs() function is added for alignment with the ISO/IEC 9899:1999 standard.

Issue 7

SD5-XSH-ERN-152 is applied, correcting the RETURN VALUE section.

Issue 8

Austin Group Defect 1108 is applied, changing the APPLICATION USAGE section.