btowc
|
定义于头文件
<wchar.h>
|
||
|
wint_t btowc
(
int
c
)
;
|
(C95 起) | |
将单字节字符
c
（重新解释为
unsigned
char
）扩展为其对应的宽字符形式。
大多数多字节字符编码使用单字节码表示ASCII字符集中的字符。此函数可用于将此类字符转换为 wchar_t 。
目录 |
参数
| c | - | 待扩展的单字节字符 |
返回值
WEOF
如果
c
是
EOF
若 ( unsigned char ) c 是初始移位状态中的有效单字节字符，则返回其宽字符表示，否则返回 WEOF 。
示例
#include <stdio.h> #include <wchar.h> #include <locale.h> #include <assert.h> void try_widen(unsigned char c) { wint_t w = btowc(c); if(w != WEOF) printf("The single-byte character %#x widens to %#x\n", c, w); else printf("The single-byte character %#x failed to widen\n", c); } int main(void) { char *loc = setlocale(LC_ALL, "lt_LT.iso88594"); assert(loc); printf("In Lithuanian ISO-8859-4 locale:\n"); try_widen('A'); try_widen('\xdf'); // German letter ß (U+00df) in ISO-8859-4 try_widen('\xf9'); // Lithuanian letter ų (U+0173) in ISO-8859-4 setlocale(LC_ALL, "lt_LT.utf8"); printf("In Lithuanian UTF-8 locale:\n"); try_widen('A'); try_widen('\xdf'); try_widen('\xf9'); }
可能的输出：
In Lithuanian ISO-8859-4 locale: The single-byte character 0x41 widens to 0x41 The single-byte character 0xdf widens to 0xdf The single-byte character 0xf9 widens to 0x173 In Lithuanian UTF-8 locale: The single-byte character 0x41 widens to 0x41 The single-byte character 0xdf failed to widen The single-byte character 0xf9 failed to widen