{"id":571,"date":"2017-02-16T00:09:21","date_gmt":"2017-02-15T16:09:21","guid":{"rendered":"https:\/\/carlos.aboutmy.info\/blog\/?p=571"},"modified":"2021-11-28T15:33:22","modified_gmt":"2021-11-28T07:33:22","slug":"%e5%86%8d%e8%ab%87-utf-8","status":"publish","type":"post","link":"https:\/\/carlos.aboutmy.info\/blog\/?p=571","title":{"rendered":"\u518d\u8ac7 UTF-8"},"content":{"rendered":"

Unicode \u81ea 2.0 \u5230\u73fe\u5728 6.0 \u90fd\u662f 21 bits \u7de8\u78bc\u3002UTF \u5c31\u662f\u5be6\u4f5c\u628a\u9019\u500b\u6700\u5927\u70ba 21 bits \u7684\u6578\u5b57\u5132\u5b58\u3002\u5e38\u898b\u7684 UTF \u6709 UTF-8\u3001UTF-16 \u53ca UTF-32\u3002\u4eca\u6b21\u8981\u518d\u8b1b\u8b1b UTF-8\u3002<\/p>\n

UTF-8 \u4e4b\u6240\u4ee5\u6d41\u884c\u662f\u56e0\u70ba\u5b83\u8ddf ASCII \u517c\u5bb9\uff0c”a” \u5b57\u5728 ASCII \u53ca UTF-8 \u6642\u90fd\u662f 0x61\uff0c\u4f46\u5728 UTF-16 \u6642\u537b\u662f 0x00 0x61\uff0c\u7576\u4e2d 0x00 \u7528 ASCII \u89e3\u8b80\u6642\u6703\u89f8\u767c null-terminated\u3002\u4e14\u5132\u5b58\u82f1\u6587\u53ca\u6578\u5b57\u53ea\u9700\u4f7f\u7528 1 byte\uff0c\u6bd4 UTF-16 \u7bc0\u7701\u4e00\u500d\u3002\u96d6\u7136\u5132\u5b58\u4e2d\u6587\u5b57\u6642\uff0cUTF-8 \u6703\u6bd4 UTF-16 \u7528\u591a\u8f03\u591a\u7a7a\u9593\uff0c\u4e0d\u904e\u9664\u975e\u662f\u5168\u4e2d\u6587\u6587\u7ae0\uff0c\u5426\u5247\u4e2d\u82f1\u6df7\u96dc\u6642\uff0c\u4f8b\u5982 HTML\uff0c\u7528 UTF-8 \u4e00\u822c\u6703\u8f03\u6709\u5132\u5b58\u5927\u5c0f\u4e0a\u7684\u597d\u8655\u3002<\/p>\n

UTF-8 \u80fd\u517c\u5bb9 ASCII \u4e4b\u9918\u53c8\u80fd\u5132\u5b58\u5927\u65bc 128 \u7de8\u78bc\u7684\u8890\u5bc6\u5728\u65bc\u53ef\u8b8a\u4f4d\u6578\uff0c\u8a73\u60c5\u53ef\u53c3\u770b \u6dfa\u8ac7 Unicode\u3001UTF-8\u3001UTF-16 \u548c UTF-32<\/a>\u3002<\/p>\n

\u4eca\u6b21\u8981\u8b1b\u7684\u662f\u5982\u4f55\u80fd\u5f97\u77e5 UTF-8 \u5b57\u4e32 (string) \u7684\u9577\u5ea6\u3002\u9019\u88e1\u8b1b\u7684\u662f\u5f9e\u8a18\u61b6\u9ad4 byte array \u5165\u624b\u3002
\n
\nint strlen_utf8(char *s)
\n{
\n\u3000int i = 0, j = 0;
\n\u3000while (s[i]){
\n\u3000\u3000if ((s[i] & 0xc0) != 0x80) j++;
\n\u3000\u3000i++;
\n\u3000}
\n\u3000return j;
\n}
\n<\/code><\/p>\n

0xc0 \u5c31\u662f 11 00 00 00
\n0x80 \u5c31\u662f 10 00 00 00<\/p>\n

\u9019\u88e1\u5c31\u662f\u770b\u770b\u5b57\u4e32\u7684\u6bcf\u500b byte \u662f\u5426 10 \u958b\u982d\uff0c\u5982\u662f 10 \u958b\u982d\uff0c\u5373\u53ea\u662f\u524d\u4e00\u500b byte \u7684 trailing (\u5f8c\u7e8c) bytes\uff0c\u662f\u540c\u4e00\u500b\u5b57\uff0c\u6240\u4ee5 count \u4e0d\u6703\u52a0 1\u3002<\/p>\n

\u770b\u5230\u9019\u88e1\uff0c\u4e0d\u5f97\u4e0d\u8d0a\u5606 UTF-8 \u9019\u500b\u8a2d\u8a08\u5f88\u8070\u660e\uff0c\u5c31\u7b97\u53ef\u8b8a\u4f4d\u5143\u4e5f\u80fd self-sync \u53ca\u6709\u6548\u5f97\u77e5\u5b57\u4e32\u9577\u5ea6\u3002<\/p>\n","protected":false},"excerpt":{"rendered":"

Unicode \u81ea 2.0 \u5230\u73fe\u5728 6.0 \u90fd\u662f 21 bits \u7de8\u78bc\u3002UTF \u5c31\u662f\u5be6\u4f5c\u628a\u9019\u500b\u6700\u5927\u70ba 21 bits \u7684\u6578\u5b57\u5132\u5b58\u3002\u5e38\u898b\u7684 UTF \u6709 UTF-8\u3001UTF-16 \u53ca UTF-32\u3002\u4eca\u6b21\u8981\u518d\u8b1b\u8b1b UTF-8\u3002 UTF-8 \u4e4b\u6240\u4ee5\u6d41\u884c\u662f\u56e0\u70ba\u5b83\u8ddf ASCII \u517c\u5bb9\uff0c”a” \u5b57\u5728 ASCII \u53ca UTF-8 \u6642\u90fd\u662f 0x61\uff0c\u4f46\u5728 UTF-16 \u6642\u537b\u662f 0x00 0x61\uff0c\u7576\u4e2d 0x00 \u7528 ASCII \u89e3\u8b80\u6642\u6703\u89f8\u767c null-terminated\u3002\u4e14\u5132\u5b58\u82f1\u6587\u53ca\u6578\u5b57\u53ea\u9700\u4f7f\u7528 1 byte\uff0c\u6bd4 UTF-16 \u7bc0\u7701\u4e00\u500d\u3002\u96d6\u7136\u5132\u5b58\u4e2d\u6587\u5b57\u6642\uff0cUTF-8 \u6703\u6bd4 UTF-16 \u7528\u591a\u8f03\u591a\u7a7a\u9593\uff0c\u4e0d\u904e\u9664\u975e\u662f\u5168\u4e2d\u6587\u6587\u7ae0\uff0c\u5426\u5247\u4e2d\u82f1\u6df7\u96dc\u6642\uff0c\u4f8b\u5982 HTML\uff0c\u7528 UTF-8 \u4e00\u822c\u6703\u8f03\u6709\u5132\u5b58\u5927\u5c0f\u4e0a\u7684\u597d\u8655\u3002 UTF-8 \u80fd\u517c\u5bb9 ASCII \u4e4b\u9918\u53c8\u80fd\u5132\u5b58\u5927\u65bc 128 \u7de8\u78bc\u7684\u8890\u5bc6\u5728\u65bc\u53ef\u8b8a\u4f4d\u6578\uff0c\u8a73\u60c5\u53ef\u53c3\u770b \u6dfa\u8ac7\u2026 Read More »<\/a><\/span><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":[],"categories":[33,15],"tags":[],"_links":{"self":[{"href":"https:\/\/carlos.aboutmy.info\/blog\/index.php?rest_route=\/wp\/v2\/posts\/571"}],"collection":[{"href":"https:\/\/carlos.aboutmy.info\/blog\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/carlos.aboutmy.info\/blog\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/carlos.aboutmy.info\/blog\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/carlos.aboutmy.info\/blog\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=571"}],"version-history":[{"count":6,"href":"https:\/\/carlos.aboutmy.info\/blog\/index.php?rest_route=\/wp\/v2\/posts\/571\/revisions"}],"predecessor-version":[{"id":578,"href":"https:\/\/carlos.aboutmy.info\/blog\/index.php?rest_route=\/wp\/v2\/posts\/571\/revisions\/578"}],"wp:attachment":[{"href":"https:\/\/carlos.aboutmy.info\/blog\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=571"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/carlos.aboutmy.info\/blog\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=571"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/carlos.aboutmy.info\/blog\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=571"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}