C99标准里的inttypes.h头文件

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C 语言_系统函数_inttypes.h深度解析阅读详情

AI摘要

本文解析了C99标准中PRIu32宏定义的意义及其使用场景，介绍了不同类型的宏定义，并提供了Ubuntu系统下inttypes.h文件的具体内容。

来源

在查看代码时看到如下类型：

fprintf(stderr,
        "\033[%"PRIu32";3%"PRIu32"m%s\033[0m",
        (color[level] >> 4) & 15,
         color[level] & 15,
         str);

其中的PRIu32是什么意思？上网搜了一下才知道是C99标准里新引入的宏定义，如下：

# define PRIu32     "u"

这些宏定义里，PRIi8、PRIu8、PRIo8以及PRIx8，其中i为有符号，u为无符号，o为8进制以及x为16进制。

inttypes.h源码

Ubuntu系统的代码路径位于/usr/include/inttypes.h下，附录如下：

/* Copyright (C) 1997-2016 Free Software Foundation, Inc.
   This file is part of the GNU C Library.

   The GNU C Library is free software; you can redistribute it and/or
   modify it under the terms of the GNU Lesser General Public
   License as published by the Free Software Foundation; either
   version 2.1 of the License, or (at your option) any later version.

   The GNU C Library is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
   Lesser General Public License for more details.

   You should have received a copy of the GNU Lesser General Public
   License along with the GNU C Library; if not, see
   <http://www.gnu.org/licenses/>.  */

/*
 *  ISO C99: 7.8 Format conversion of integer types <inttypes.h>
 */

#ifndef _INTTYPES_H
#define _INTTYPES_H 1

#include <features.h>
/* Get the type definitions.  */
#include <stdint.h>

/* Get a definition for wchar_t.  But we must not define wchar_t itself.  */
#ifndef ____gwchar_t_defined
# ifdef __cplusplus
#  define __gwchar_t wchar_t
# elif defined __WCHAR_TYPE__
typedef __WCHAR_TYPE__ __gwchar_t;
# else
#  define __need_wchar_t
#  include <stddef.h>
typedef wchar_t __gwchar_t;
# endif
# define ____gwchar_t_defined   1
#endif

# if __WORDSIZE == 64
#  define __PRI64_PREFIX    "l"
#  define __PRIPTR_PREFIX   "l"
# else
#  define __PRI64_PREFIX    "ll"
#  define __PRIPTR_PREFIX
# endif

/* Macros for printing format specifiers.  */

/* Decimal notation.  */
# define PRId8      "d"
# define PRId16     "d"
# define PRId32     "d"
# define PRId64     __PRI64_PREFIX "d"

# define PRIdLEAST8 "d"
# define PRIdLEAST16    "d"
# define PRIdLEAST32    "d"
# define PRIdLEAST64    __PRI64_PREFIX "d"

# define PRIdFAST8  "d"
# define PRIdFAST16 __PRIPTR_PREFIX "d"
# define PRIdFAST32 __PRIPTR_PREFIX "d"
# define PRIdFAST64 __PRI64_PREFIX "d"


# define PRIi8      "i"
# define PRIi16     "i"
# define PRIi32     "i"
# define PRIi64     __PRI64_PREFIX "i"

# define PRIiLEAST8 "i"
# define PRIiLEAST16    "i"
# define PRIiLEAST32    "i"
# define PRIiLEAST64    __PRI64_PREFIX "i"

# define PRIiFAST8  "i"
# define PRIiFAST16 __PRIPTR_PREFIX "i"
# define PRIiFAST32 __PRIPTR_PREFIX "i"
# define PRIiFAST64 __PRI64_PREFIX "i"

/* Octal notation.  */
# define PRIo8      "o"
# define PRIo16     "o"
# define PRIo32     "o"
# define PRIo64     __PRI64_PREFIX "o"

# define PRIoLEAST8 "o"
# define PRIoLEAST16    "o"
# define PRIoLEAST32    "o"
# define PRIoLEAST64    __PRI64_PREFIX "o"

# define PRIoFAST8  "o"
# define PRIoFAST16 __PRIPTR_PREFIX "o"
# define PRIoFAST32 __PRIPTR_PREFIX "o"
# define PRIoFAST64 __PRI64_PREFIX "o"

/* Unsigned integers.  */
# define PRIu8      "u"
# define PRIu16     "u"
# define PRIu32     "u"
# define PRIu64     __PRI64_PREFIX "u"

# define PRIuLEAST8 "u"
# define PRIuLEAST16    "u"
# define PRIuLEAST32    "u"
# define PRIuLEAST64    __PRI64_PREFIX "u"

# define PRIuFAST8  "u"
# define PRIuFAST16 __PRIPTR_PREFIX "u"
# define PRIuFAST32 __PRIPTR_PREFIX "u"
# define PRIuFAST64 __PRI64_PREFIX "u"

/* lowercase hexadecimal notation.  */
# define PRIx8      "x"
# define PRIx16     "x"
# define PRIx32     "x"
# define PRIx64     __PRI64_PREFIX "x"

# define PRIxLEAST8 "x"
# define PRIxLEAST16    "x"
# define PRIxLEAST32    "x"
# define PRIxLEAST64    __PRI64_PREFIX "x"

# define PRIxFAST8  "x"
# define PRIxFAST16 __PRIPTR_PREFIX "x"
# define PRIxFAST32 __PRIPTR_PREFIX "x"
# define PRIxFAST64 __PRI64_PREFIX "x"

/* UPPERCASE hexadecimal notation.  */
# define PRIX8      "X"
# define PRIX16     "X"
# define PRIX32     "X"
# define PRIX64     __PRI64_PREFIX "X"

# define PRIXLEAST8 "X"
# define PRIXLEAST16    "X"
# define PRIXLEAST32    "X"
# define PRIXLEAST64    __PRI64_PREFIX "X"

# define PRIXFAST8  "X"
# define PRIXFAST16 __PRIPTR_PREFIX "X"
# define PRIXFAST32 __PRIPTR_PREFIX "X"
# define PRIXFAST64 __PRI64_PREFIX "X"


/* Macros for printing `intmax_t' and `uintmax_t'.  */
# define PRIdMAX    __PRI64_PREFIX "d"
# define PRIiMAX    __PRI64_PREFIX "i"
# define PRIoMAX    __PRI64_PREFIX "o"
# define PRIuMAX    __PRI64_PREFIX "u"
# define PRIxMAX    __PRI64_PREFIX "x"
# define PRIXMAX    __PRI64_PREFIX "X"


/* Macros for printing `intptr_t' and `uintptr_t'.  */
# define PRIdPTR    __PRIPTR_PREFIX "d"
# define PRIiPTR    __PRIPTR_PREFIX "i"
# define PRIoPTR    __PRIPTR_PREFIX "o"
# define PRIuPTR    __PRIPTR_PREFIX "u"
# define PRIxPTR    __PRIPTR_PREFIX "x"
# define PRIXPTR    __PRIPTR_PREFIX "X"


/* Macros for scanning format specifiers.  */

/* Signed decimal notation.  */
# define SCNd8      "hhd"
# define SCNd16     "hd"
# define SCNd32     "d"
# define SCNd64     __PRI64_PREFIX "d"

# define SCNdLEAST8 "hhd"
# define SCNdLEAST16    "hd"
# define SCNdLEAST32    "d"
# define SCNdLEAST64    __PRI64_PREFIX "d"

# define SCNdFAST8  "hhd"
# define SCNdFAST16 __PRIPTR_PREFIX "d"
# define SCNdFAST32 __PRIPTR_PREFIX "d"
# define SCNdFAST64 __PRI64_PREFIX "d"

/* Signed decimal notation.  */
# define SCNi8      "hhi"
# define SCNi16     "hi"
# define SCNi32     "i"
# define SCNi64     __PRI64_PREFIX "i"

# define SCNiLEAST8 "hhi"
# define SCNiLEAST16    "hi"
# define SCNiLEAST32    "i"
# define SCNiLEAST64    __PRI64_PREFIX "i"

# define SCNiFAST8  "hhi"
# define SCNiFAST16 __PRIPTR_PREFIX "i"
# define SCNiFAST32 __PRIPTR_PREFIX "i"
# define SCNiFAST64 __PRI64_PREFIX "i"

/* Unsigned decimal notation.  */
# define SCNu8      "hhu"
# define SCNu16     "hu"
# define SCNu32     "u"
# define SCNu64     __PRI64_PREFIX "u"

# define SCNuLEAST8 "hhu"
# define SCNuLEAST16    "hu"
# define SCNuLEAST32    "u"
# define SCNuLEAST64    __PRI64_PREFIX "u"

# define SCNuFAST8  "hhu"
# define SCNuFAST16 __PRIPTR_PREFIX "u"
# define SCNuFAST32 __PRIPTR_PREFIX "u"
# define SCNuFAST64 __PRI64_PREFIX "u"

/* Octal notation.  */
# define SCNo8      "hho"
# define SCNo16     "ho"
# define SCNo32     "o"
# define SCNo64     __PRI64_PREFIX "o"

# define SCNoLEAST8 "hho"
# define SCNoLEAST16    "ho"
# define SCNoLEAST32    "o"
# define SCNoLEAST64    __PRI64_PREFIX "o"

# define SCNoFAST8  "hho"
# define SCNoFAST16 __PRIPTR_PREFIX "o"
# define SCNoFAST32 __PRIPTR_PREFIX "o"
# define SCNoFAST64 __PRI64_PREFIX "o"

/* Hexadecimal notation.  */
# define SCNx8      "hhx"
# define SCNx16     "hx"
# define SCNx32     "x"
# define SCNx64     __PRI64_PREFIX "x"

# define SCNxLEAST8 "hhx"
# define SCNxLEAST16    "hx"
# define SCNxLEAST32    "x"
# define SCNxLEAST64    __PRI64_PREFIX "x"

# define SCNxFAST8  "hhx"
# define SCNxFAST16 __PRIPTR_PREFIX "x"
# define SCNxFAST32 __PRIPTR_PREFIX "x"
# define SCNxFAST64 __PRI64_PREFIX "x"


/* Macros for scanning `intmax_t' and `uintmax_t'.  */
# define SCNdMAX    __PRI64_PREFIX "d"
# define SCNiMAX    __PRI64_PREFIX "i"
# define SCNoMAX    __PRI64_PREFIX "o"
# define SCNuMAX    __PRI64_PREFIX "u"
# define SCNxMAX    __PRI64_PREFIX "x"

/* Macros for scaning `intptr_t' and `uintptr_t'.  */
# define SCNdPTR    __PRIPTR_PREFIX "d"
# define SCNiPTR    __PRIPTR_PREFIX "i"
# define SCNoPTR    __PRIPTR_PREFIX "o"
# define SCNuPTR    __PRIPTR_PREFIX "u"
# define SCNxPTR    __PRIPTR_PREFIX "x"


__BEGIN_DECLS

#if __WORDSIZE == 64

/* We have to define the `uintmax_t' type using `ldiv_t'.  */
typedef struct
  {
    long int quot;      /* Quotient.  */
    long int rem;       /* Remainder.  */
  } imaxdiv_t;

#else

/* We have to define the `uintmax_t' type using `lldiv_t'.  */
typedef struct
  {
    __extension__ long long int quot;   /* Quotient.  */
    __extension__ long long int rem;    /* Remainder.  */
  } imaxdiv_t;

#endif


/* Compute absolute value of N.  */
extern intmax_t imaxabs (intmax_t __n) __THROW __attribute__ ((__const__));

/* Return the `imaxdiv_t' representation of the value of NUMER over DENOM. */
extern imaxdiv_t imaxdiv (intmax_t __numer, intmax_t __denom)
      __THROW __attribute__ ((__const__));

/* Like `strtol' but convert to `intmax_t'.  */
extern intmax_t strtoimax (const char *__restrict __nptr,
               char **__restrict __endptr, int __base) __THROW;

/* Like `strtoul' but convert to `uintmax_t'.  */
extern uintmax_t strtoumax (const char *__restrict __nptr,
                char ** __restrict __endptr, int __base) __THROW;

/* Like `wcstol' but convert to `intmax_t'.  */
extern intmax_t wcstoimax (const __gwchar_t *__restrict __nptr,
               __gwchar_t **__restrict __endptr, int __base)
     __THROW;

/* Like `wcstoul' but convert to `uintmax_t'.  */
extern uintmax_t wcstoumax (const __gwchar_t *__restrict __nptr,
                __gwchar_t ** __restrict __endptr, int __base)
     __THROW;

#ifdef __USE_EXTERN_INLINES

# if __WORDSIZE == 64

extern long int __strtol_internal (const char *__restrict __nptr,
                   char **__restrict __endptr,
                   int __base, int __group)
  __THROW __nonnull ((1)) __wur;
/* Like `strtol' but convert to `intmax_t'.  */
__extern_inline intmax_t
__NTH (strtoimax (const char *__restrict nptr, char **__restrict endptr,
          int base))
{
  return __strtol_internal (nptr, endptr, base, 0);
}

extern unsigned long int __strtoul_internal (const char *__restrict __nptr,
                         char ** __restrict __endptr,
                         int __base, int __group)
  __THROW __nonnull ((1)) __wur;
/* Like `strtoul' but convert to `uintmax_t'.  */
__extern_inline uintmax_t
__NTH (strtoumax (const char *__restrict nptr, char **__restrict endptr,
          int base))
{
  return __strtoul_internal (nptr, endptr, base, 0);
}

extern long int __wcstol_internal (const __gwchar_t * __restrict __nptr,
                   __gwchar_t **__restrict __endptr,
                   int __base, int __group)
  __THROW __nonnull ((1)) __wur;
/* Like `wcstol' but convert to `intmax_t'.  */
__extern_inline intmax_t
__NTH (wcstoimax (const __gwchar_t *__restrict nptr,
          __gwchar_t **__restrict endptr, int base))
{
  return __wcstol_internal (nptr, endptr, base, 0);
}

extern unsigned long int __wcstoul_internal (const __gwchar_t *
                         __restrict __nptr,
                         __gwchar_t **
                         __restrict __endptr,
                         int __base, int __group)
  __THROW __nonnull ((1)) __wur;
/* Like `wcstoul' but convert to `uintmax_t'.  */
__extern_inline uintmax_t
__NTH (wcstoumax (const __gwchar_t *__restrict nptr,
          __gwchar_t **__restrict endptr, int base))
{
  return __wcstoul_internal (nptr, endptr, base, 0);
}

# else /* __WORDSIZE == 32 */

__extension__
extern long long int __strtoll_internal (const char *__restrict __nptr,
                     char **__restrict __endptr,
                     int __base, int __group)
  __THROW __nonnull ((1)) __wur;
/* Like `strtol' but convert to `intmax_t'.  */
__extern_inline intmax_t
__NTH (strtoimax (const char *__restrict nptr, char **__restrict endptr,
          int base))
{
  return __strtoll_internal (nptr, endptr, base, 0);
}

__extension__
extern unsigned long long int __strtoull_internal (const char *
                           __restrict __nptr,
                           char **
                           __restrict __endptr,
                           int __base,
                           int __group)
  __THROW __nonnull ((1)) __wur;
/* Like `strtoul' but convert to `uintmax_t'.  */
__extern_inline uintmax_t
__NTH (strtoumax (const char *__restrict nptr, char **__restrict endptr,
          int base))
{
  return __strtoull_internal (nptr, endptr, base, 0);
}

__extension__
extern long long int __wcstoll_internal (const __gwchar_t *__restrict __nptr,
                     __gwchar_t **__restrict __endptr,
                     int __base, int __group)
  __THROW __nonnull ((1)) __wur;
/* Like `wcstol' but convert to `intmax_t'.  */
__extern_inline intmax_t
__NTH (wcstoimax (const __gwchar_t *__restrict nptr,
          __gwchar_t **__restrict endptr, int base))
{
  return __wcstoll_internal (nptr, endptr, base, 0);
}


__extension__
extern unsigned long long int __wcstoull_internal (const __gwchar_t *
                           __restrict __nptr,
                           __gwchar_t **
                           __restrict __endptr,
                           int __base,
                           int __group)
  __THROW __nonnull ((1)) __wur;
/* Like `wcstoul' but convert to `uintmax_t'.  */
__extern_inline uintmax_t
__NTH (wcstoumax (const __gwchar_t *__restrict nptr,
          __gwchar_t **__restrict endptr, int base))
{
  return __wcstoull_internal (nptr, endptr, base, 0);
}

# endif /* __WORDSIZE == 32 */
#endif  /* Use extern inlines.  */

__END_DECLS

#endif /* inttypes.h */