请问Posix的供应格式字符串宏的printf / scanf的? [英] Does Posix supply format string macros for printf/scanf?
问题描述
的的printf
和 scanf函数
在C函数家庭消耗对应于基本的原始格式说明了一把数据类型&ndash的; %d个
为 INT
,%LLU
为无符号长long int类型
等
The printf
and scanf
families of functions in C consume a handful of primitive format specifiers that correspond to the fundamental data types – %d
for int
, %llu
for unsigned long long int
, etc.
不过,也有大量的标准化的类型别名,一个想在实践中使用,如的int32fast_t
,和一个不能也不应该不必知道底层的基本类型。对于 stdint.h
的别名,C标准谢天谢地指定了一组宏来生成相应的格式字符串,如 PRI32 $ C $的C>在
inttypes.h
。
However, there are a large number of standardized type aliases that one would like to use in practice, such as int32fast_t
, and one cannot and should not have to know the underlying fundamental type. For the aliases in stdint.h
, the C standard thankfully specifies a set of macros to generate the corresponding format strings, like PRI32
, in inttypes.h
.
有没有类似的组宏对POSIX的? POSIX有一个像 ssize_t供
,将为pid_t
, rlim_t
, suseconds_t
等,这些都对基本intgral类型的所有变化。怎么可以在一个可移植的格式字符串使用这些类型?
Is there an analogous set of macros for Posix? Posix has tons of opaque types like ssize_t
, pid_t
, rlim_t
, suseconds_t
, etc, which are all variations on the basic intgral types. How can one portably use those types in format strings?
推荐答案
在了sfio包(AT&功放的一部分; T实验室'开源AST软件)具有类似于printf和scanf函数功能,这让你指定数值的大小(通常使用的sizeof()
)作为附加参数。一些例子:
The sfio package (part of AT&T Labs' open source AST software) has functions analogous to printf and scanf which let you specify the size of the numeric value (typically using sizeof()
) as an additional parameter. Some examples:
sfprintf(sfstdout, "%I*d", sizeof(intval), intval);
sfscanf(sfstdin, "%I*f", sizeof(fltval), &fltval);
USENIX纸:扩展数据格式使用SFIO
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