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man pages section 3: Library Interfaces and Headers

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Updated: Thursday, June 13, 2019
 
 

inttypes(3HEAD)

Name

inttypes.h, inttypes - fixed size integer types

Synopsis

#include <inttypes.h> 

Description

The <inttypes.h> header includes the <stdint.h> header.

The <inttypes.h> header includes a definition of the following type:

imaxdiv_t

structure type that is the type of the value returned by the imaxdiv() function.

The following macros are defined. Each expands to a character string literal containing a conversion specifier, possibly modified by a length modifier, suitable for use within the format argument of a formatted input/output function when converting the corresponding integer type. These macros have the general form of PRI (character string literals for the fprintf() and fwprintf() family of functions) or SCN (character string literals for the fscanf() and fwscanf() family of functions), followed by the conversion specifier, followed by a name corresponding to a similar type name in <stdint.h>. In these names, N represents the width of the type as described in <stdint.h>. For example, PRIdFAST32 can be used in a format string to print the value of an integer of type int_fast32_t.

The fprintf() macros for signed integers are:

PRIdN  PRIdLEASTN  PRIdFASTN  PRIdMAX  PRIdPTR
PRIiN  PRIiLEASTN  PRIiFASTN  PRIiMAX  PRIiPTR

The fprintf() macros for unsigned integers are:

PRIoN   PRIoLEASTN  PRIoFASTN  PRIoMAX  PRIoPTR
PRIuN   PRIuLEASTN  PRIuFASTN  PRIuMAX  PRIuPTR
PRIxN   PRIxLEASTN  PRIxFASTN  PRIxMAX  PRIxPTR
PRIXN   PRIXLEASTN  PRIXFASTN  PRIXMAX  PRIXPTR

The fscanf() macros for signed integers are:

SCNdN  SCNdLEASTN  SCNdFASTN  SCNdMAX  SCNdPTR
SCNiN  SCNiLEASTN  SCNiFASTN  SCNiMAX  SCNiPTR

The fscanf() macros for unsigned integers are:

SCNoN  SCNoLEASTN  SCNoFASTN  SCNoMAX  SCNoPTR
SCNuN  SCNuLEASTN  SCNuFASTN  SCNuMAX  SCNuPTR
SCNxN  SCNxLEASTN  SCNxFASTN  SCNxMAX  SCNxPTR

For each type that the implementation provides in <stdint.h>, the corresponding fprintf() and fwprintf() macros must be defined. The corresponding fscanf() and fwscanf() macros must be defined as well, unless the implementation does not have a suitable modifier for the type.

Usage

The purpose of <inttypes.h> is to provide a set of integer types whose definitions are consistent across machines and independent of operating systems and other implementation idiosyncrasies. It defines, with a typedef, integer types of various sizes. Implementations are free to typedef them as ISO C standard integer types or extensions that they support. Consistent use of this header greatly increases the portability of applications across platforms.

Examples

Example 1 Use of Macro

The following code uses one of the macros available through <inttypes.h>.

#include <inttypes.h>
#include <wchar.h>
int main(void)
{
     uintmax_t i = UINTMAX_MAX; // This type always exists.
     wprintf("The largest integer value is %020"
          PRIxMAX, "\n", i);
     return 0;
}

Attributes

See attributes(7) for descriptions of the following attributes:

ATTRIBUTE TYPE
ATTRIBUTE VALUE
Interface Stability
Committed
Standard

See Also

imaxdiv(3C), attributes(7), standards(7)