btowc
來自 cppreference.com
| 在標頭檔案 <wchar.h> 中定義 |
||
| wint_t btowc( int c ); |
(自 C95 起) | |
將單位元組字元 c（重新解釋為 unsigned char）擴充套件為對應的寬字元。
大多數多位元組字元編碼使用單位元組程式碼來表示 ASCII 字元集中的字元。此函式可用於將此類字元轉換為 wchar_t。
目錄 |
[編輯] 引數
| c | - | 要擴充套件的單位元組字元 |
[編輯] 返回值
如果 c 為 EOF，則為 WEOF。
如果 (unsigned char)c 在初始移位狀態下是有效的單位元組字元，則返回 c 的寬字元表示；否則返回 WEOF。
[編輯] 示例
執行此程式碼
#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'); }
可能的輸出
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
