NAME

inttypes — standard fixed-size integer types

SYNOPSIS

#include <inttypes.h>

DESCRIPTION

The <inttypes.h> header describes a set of format specifier macros aimed to increase portability both within and across operating systems. It includes the <stdint.h> header and extends it with additional facilities.

Each of the following macros expand to a character string literal containing the format specifier suitable for use within the format argument of a formatted I/O function such as printf(3). Each macro contains an identifier (PRI or SCN), a conversion specifier, and a possible length modifier.

The length modifier follows the integer types described in stdint(3):

int8_t	uint8_t
int16_t	uint16_t
int32_t	uint32_t
int64_t	uint64_t
int_least8_t	uint_least8_t
int_least16_t	uint_least16_t
int_least32_t	uint_least32_t
int_least64_t	uint_least64_t
int_fast8_t	uint_fast8_t
int_fast16_t	uint_fast16_t
int_fast32_t	uint_fast32_t
int_fast64_t	uint_fast64_t
intmax_t	uintmax_t
intptr_t	uintptr_t

The following format specifiers are defined for the fprintf(3) and fscanf(3) families, respectively:

PRI?8	SCN?8
PRI?16	SCN?16
PRI?32	SCN?32
PRI?64	SCN?64
PRI?LEAST8	SCN?LEAST8
PRI?LEAST16	SCN?LEAST16
PRI?LEAST32	SCN?LEAST32
PRI?LEAST64	SCN?LEAST64
PRI?FAST8	SCN?FAST8
PRI?FAST16	SCN?FAST16
PRI?FAST32	SCN?FAST32
PRI?FAST64	SCN?FAST64
PRI?MAX	SCN?MAX
PRI?PTR	SCN?PTR

The available conversion specifiers, “?” in above, are d and i for signed integers and o, u, x, and X for unsigned integers. The X is not available for the fscanf(3) family. Without the length modifier these would correspond with %d, %i, %o, %u, %x, and %X, respectively.

EXAMPLES

The following example demonstrates typical usage:

uint64_t i = 123; 
 
... 
 
(void)printf("i = %"PRIu64"\n", i);

SEE ALSO

printf(3), scanf(3), stdint(3)

STANDARDS

The <inttypes.h> header conforms to ISO/IEC 9899:1999 (“ISO C99”) and IEEE Std 1003.1-2001 (“POSIX.1”).

HISTORY

The <inttypes.h> header was first introduced in NetBSD 1.6.