<inttypes.h>(0P)                                    POSIX Programmer's Manual                                   <inttypes.h>(0P)



NAME
       inttypes.h - fixed size integer types

SYNOPSIS
       #include <inttypes.h>

DESCRIPTION
       Some  of  the  functionality  described  on this reference page extends the ISO C standard. Applications shall define the
       appropriate feature test macro (see the System Interfaces volume of IEEE Std 1003.1-2001, Section  2.2,  The  Compilation
       Environment) to enable the visibility of these symbols in this header.

       The <inttypes.h> header shall include the <stdint.h> header.

       The <inttypes.h> header shall include a definition of at least the following type:

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


       The following macros shall be defined. Each expands to a character string literal containing a conversion specifier, pos-
       sibly 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 shall be
       defined and the corresponding fscanf() and fwscanf() macros shall be defined unless the implementation does  not  have  a
       suitable modifier for the type.

       The following shall be declared as functions and may also be defined as macros. Function prototypes shall be provided.


              intmax_t  imaxabs(intmax_t);
              imaxdiv_t imaxdiv(intmax_t, intmax_t);
              intmax_t  strtoimax(const char *restrict, char **restrict, int);
              uintmax_t strtoumax(const char *restrict, char **restrict, int);
              intmax_t  wcstoimax(const wchar_t *restrict, wchar_t **restrict, int);
              uintmax_t wcstoumax(const wchar_t *restrict, wchar_t **restrict, int);

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

       The following sections are informative.

APPLICATION 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, via typedef, integer types of var-
       ious  sizes.  Implementations  are  free to typedef them as ISO C standard integer types or extensions that they support.
       Consistent use of this header will greatly increase the portability of applications across platforms.

RATIONALE
       The ISO/IEC 9899:1990 standard specified that the language should support four signed and unsigned  integer  data  types-
       char, short, int, and long- but placed very little requirement on their size other than that int and short be at least 16
       bits and long be at least as long as int and not smaller than 32 bits. For 16-bit systems, most implementations  assigned
       8,  16,  16, and 32 bits to char, short, int, and long, respectively. For 32-bit systems, the common practice has been to
       assign 8, 16, 32, and 32 bits to these types. This difference in int size can create some problems for users who  migrate
       from  one  system to another which assigns different sizes to integer types, because the ISO C standard integer promotion
       rule can produce silent changes unexpectedly. The need for defining an extended integer type increased with the introduc-
       tion of 64-bit systems.

FUTURE DIRECTIONS
       Macro  names  beginning with PRI or SCN followed by any lowercase letter or 'X' may be added to the macros defined in the
       <inttypes.h> header.

SEE ALSO
       The System Interfaces volume of IEEE Std 1003.1-2001, imaxdiv()

COPYRIGHT
       Portions of this text are reprinted and reproduced in electronic form from IEEE Std 1003.1, 2003  Edition,  Standard  for
       Information  Technology -- Portable Operating System Interface (POSIX), The Open Group Base Specifications Issue 6, Copy-
       right (C) 2001-2003 by the Institute of Electrical and Electronics Engineers, Inc and The Open Group. In the event of any
       discrepancy  between this version and the original IEEE and The Open Group Standard, the original IEEE and The Open Group
       Standard  is  the  referee   document.   The   original   Standard   can   be   obtained   online   at   http://www.open-
       group.org/unix/online.html .



IEEE/The Open Group                                           2003                                              <inttypes.h>(0P)