If I have an integer variable I can use sscanf as shown below by using the format specifier %d.
如果我有一个整型变量，我可以使用sscanf，如下所示，使用format specifier %d。
sscanf (line, "Value of integer: %d\n", &my_integer);
Where can I find format specifiers for uint8_t, uint16_t, uint32_t and uint64_t?
在哪里可以找到uint8_t、uint16_t、uint32_t和uint64_t的格式说明符?
uint64_t has probably %lu.
uint64_t可能%。
6 个解决方案
#1
79
They are declared in <inttypes.h> as macros: SCNd8, SCNd16, SCNd32 and SCNd64. Example (for int32_t):
它们在
sscanf (line, "Value of integer: %" SCNd32 "\n", &my_integer);
Their format is PRI (for printf)/SCN (for scan) then o, u, x, X d, i for the corresponding specifier then nothing, LEAST, FAST, MAX then the size (obviously there is no size for MAX). Some other examples: PRIo8, PRIuMAX, SCNoFAST16.
它们的格式是PRI(用于printf)/SCN(用于扫描)，然后o, u, x, x d, i对应的说明符，然后没有任何东西，至少，快速，最大值，然后是大小(显然，MAX没有大小)。还有一些例子:PRIo8, PRIuMAX, SCNoFAST16。
Edit: BTW a related question asked why that method was used. You may find the answers interesting.
编辑:顺便问一下，为什么使用这个方法?你会发现答案很有趣。
#2
7
As others said, include <stdint.h> header that defines the format macros. In C++, however, define __STDC_FORMAT_MACROS prior to including it. From stdint.h:
正如其他人所说，包括
/* The ISO C99 standard specifies that these macros must only be
defined if explicitly requested. */
#if !defined __cplusplus || defined __STDC_FORMAT_MACROS
#3
2
According to 7.19.6 Formatted input/output functions of ISO/IEC 9899:TC2, there are no such format specifiers (so I doubt there any for C++2003). Even though there are some #define-macros available in C99's inttypes.h, cinttypes and inttypes.h are not part of the current standard. Of course, fixed-size integer types are non-standard as well.
根据ISO/ iec9899:TC2的格式输入/输出功能，没有这样的格式说明(所以我怀疑c++ 2003是否有)。尽管C99的inttypes中有一些#define-宏。h,cinttypes inttypes。h不是当前标准的一部分。当然，固定大小的整数类型也是不标准的。
Anyways, I seriously recommemend using streams instead:
无论如何，我认真地建议用流来代替:
<any_type> x;
f >> x;
and be done. E.g.:
和做。例如:
std::stringstream ss;
uint32_t u;
std::cin >> u;
This has the advantage that one time in the future, changing the type of the variable does not cause a cascade of subtle bugs and undefined behaviour.
这在将来有一段时间的优势，改变变量的类型不会导致细微的错误和未定义的行为。
#4
0
In C, the header is <inttypes.h>, and formats such as SCNX8, SCNd16.
在C中，header是
The same header probably works for C++ too.
同样的标题可能也适用于c++。
#5
0
The right format to read a uint64_t (typedef unsigned long long int) is, with scanf and not sscanf, "%" SCNu64 and for print is also SCNu64 Example. in your code you read for example my_integer variable, then you do scanf ("Value of integer:%" SCNu64, & my_integer); and to write the same but with printf.
读取uint64_t (typedef unsigned long long int)的正确格式是，使用scanf而不是sscanf，“%”SCNu64和打印也是SCNu64示例。在您的代码中，您读取的是my_integer变量，然后是scanf(“整数的值:%”SCNu64， & my_integer);和printf一样。
#6
#1
79
They are declared in <inttypes.h> as macros: SCNd8, SCNd16, SCNd32 and SCNd64. Example (for int32_t):
它们在
sscanf (line, "Value of integer: %" SCNd32 "\n", &my_integer);
Their format is PRI (for printf)/SCN (for scan) then o, u, x, X d, i for the corresponding specifier then nothing, LEAST, FAST, MAX then the size (obviously there is no size for MAX). Some other examples: PRIo8, PRIuMAX, SCNoFAST16.
它们的格式是PRI(用于printf)/SCN(用于扫描)，然后o, u, x, x d, i对应的说明符，然后没有任何东西，至少，快速，最大值，然后是大小(显然，MAX没有大小)。还有一些例子:PRIo8, PRIuMAX, SCNoFAST16。
Edit: BTW a related question asked why that method was used. You may find the answers interesting.
编辑:顺便问一下，为什么使用这个方法?你会发现答案很有趣。
#2
7
As others said, include <stdint.h> header that defines the format macros. In C++, however, define __STDC_FORMAT_MACROS prior to including it. From stdint.h:
正如其他人所说，包括
/* The ISO C99 standard specifies that these macros must only be
defined if explicitly requested. */
#if !defined __cplusplus || defined __STDC_FORMAT_MACROS
#3
2
According to 7.19.6 Formatted input/output functions of ISO/IEC 9899:TC2, there are no such format specifiers (so I doubt there any for C++2003). Even though there are some #define-macros available in C99's inttypes.h, cinttypes and inttypes.h are not part of the current standard. Of course, fixed-size integer types are non-standard as well.
根据ISO/ iec9899:TC2的格式输入/输出功能，没有这样的格式说明(所以我怀疑c++ 2003是否有)。尽管C99的inttypes中有一些#define-宏。h,cinttypes inttypes。h不是当前标准的一部分。当然，固定大小的整数类型也是不标准的。
Anyways, I seriously recommemend using streams instead:
无论如何，我认真地建议用流来代替:
<any_type> x;
f >> x;
and be done. E.g.:
和做。例如:
std::stringstream ss;
uint32_t u;
std::cin >> u;
This has the advantage that one time in the future, changing the type of the variable does not cause a cascade of subtle bugs and undefined behaviour.
这在将来有一段时间的优势，改变变量的类型不会导致细微的错误和未定义的行为。
#4
0
In C, the header is <inttypes.h>, and formats such as SCNX8, SCNd16.
在C中，header是
The same header probably works for C++ too.
同样的标题可能也适用于c++。
#5
0
The right format to read a uint64_t (typedef unsigned long long int) is, with scanf and not sscanf, "%" SCNu64 and for print is also SCNu64 Example. in your code you read for example my_integer variable, then you do scanf ("Value of integer:%" SCNu64, & my_integer); and to write the same but with printf.
读取uint64_t (typedef unsigned long long int)的正确格式是，使用scanf而不是sscanf，“%”SCNu64和打印也是SCNu64示例。在您的代码中，您读取的是my_integer变量，然后是scanf(“整数的值:%”SCNu64， & my_integer);和printf一样。