d [^特定者在C

发布时间：2020-12-16 03:33:30 所属栏目：百科来源：网络整理

导读：sscanf(line,"%d %64[^n",seconds,message); d [^表示 – 最多64个字符？它应该与GNU C编译器一起使用吗？解决方法这意味着“最多可读取64个字符或在到达换行符时停止,以先到者为准”.它由标准指定,因此所有标准库都必须支持它. C11 7.21.6.2 [ Matches

sscanf(line,"%d %64[^n",&seconds,message);

d [^表示 – 最多64个字符？
它应该与GNU C编译器一起使用吗？

解决方法

这意味着“最多可读取64个字符或在到达换行符时停止,以先到者为准”.它由标准指定,因此所有标准库都必须支持它.

C11 7.21.6.2

[ Matches a nonempty sequence of characters from a set of expected
characters (the scanset).
[…]
The conversion specifier includes all subsequent characters in the
format string,up to and including the matching right bracket (]).

The characters between the brackets (the scanlist) compose the
scanset,unless the character after the left bracket is a circumflex
(^),in which case the scanset contains all characters that do not
appear in the scanlist between the circumflex and the right bracket.

如评论中所述,可能需要匹配]来划分扫描列表.不需要s说明符.

（编辑：李大同）

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