{"id":2378,"date":"2025-10-14T14:44:24","date_gmt":"2025-10-14T06:44:24","guid":{"rendered":"https:\/\/www.madbull.site\/?p=2378"},"modified":"2025-10-16T09:44:50","modified_gmt":"2025-10-16T01:44:50","slug":"os-readfile-%e5%92%8c-io-readall-%e7%9a%84%e5%8c%ba%e5%88%ab","status":"publish","type":"post","link":"https:\/\/www.madbull.site\/?p=2378","title":{"rendered":"\u5728golang\u4e2d\uff0cos.ReadFile \u548c io.ReadAll \u7684\u533a\u522b"},"content":{"rendered":"\n

os.ReadFile<\/code> \u548c io.ReadAll<\/code> \u90fd\u662f\u7528\u6765\u8bfb\u53d6\u6570\u636e<\/strong>\u7684\u51fd\u6570\uff0c\u4f46\u5b83\u4eec\u7684\u8bbe\u8ba1\u76ee\u6807\u3001\u4f7f\u7528\u573a\u666f\u548c\u5e95\u5c42\u884c\u4e3a\u6709\u663e\u8457\u533a\u522b\u3002<\/p>\n\n\n\n

\u6211\u4eec\u6765\u6df1\u5165\u5bf9\u6bd4\u5b83\u4eec\u7684 \u529f\u80fd\u3001\u6027\u80fd\u3001\u4f7f\u7528\u65b9\u5f0f\u548c\u9002\u7528\u573a\u666f<\/strong>\u3002<\/p>\n\n\n\n

\n\n\n\n

\ud83d\udcda \u4e00\u3001\u57fa\u672c\u5b9a\u4e49<\/h2>\n\n\n\n
\u51fd\u6570<\/th>\u5305<\/th>\u4f5c\u7528<\/th><\/tr><\/thead>
os.ReadFile(filename)<\/code><\/td>os<\/code><\/td>\u4ece\u6587\u4ef6<\/strong>\u8bfb\u53d6\u6240\u6709\u5185\u5bb9\uff0c\u8fd4\u56de []byte<\/code><\/td><\/tr>
io.ReadAll(reader)<\/code><\/td>io<\/code><\/td>\u4ece\u4efb\u610f io.Reader<\/code> \u8bfb\u53d6\u6240\u6709\u5185\u5bb9\uff0c\u76f4\u5230 EOF<\/code>\uff0c\u8fd4\u56de []byte<\/code><\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n
\n\n\n\n

\u2705 \u4e8c\u3001\u51fd\u6570\u7b7e\u540d\u5bf9\u6bd4<\/h2>\n\n\n\n
\/\/ os.ReadFile\nfunc ReadFile(name string) ([]byte, error)\n\n\/\/ io.ReadAll\nfunc ReadAll(r Reader) ([]byte, error)<\/code><\/pre>\n\n\n\n
    \n
  • os.ReadFile<\/code> \u63a5\u6536\u4e00\u4e2a \u6587\u4ef6\u8def\u5f84\u5b57\u7b26\u4e32<\/strong><\/li>\n\n\n\n
  • io.ReadAll<\/code> \u63a5\u6536\u4e00\u4e2a \u5b9e\u73b0\u4e86 io.Reader<\/code> \u63a5\u53e3\u7684\u5bf9\u8c61<\/strong><\/li>\n<\/ul>\n\n\n\n
    \n\n\n\n
    \ud83d\udd0d \u4e09\u3001\u6838\u5fc3\u533a\u522b\u8be6\u89e3<\/h2>\n\n\n\n
    \u5bf9\u6bd4\u9879<\/th>os.ReadFile<\/code><\/th>io.ReadAll<\/code><\/th><\/tr><\/thead>
    \u6570\u636e\u6e90<\/strong><\/td>\u53ea\u80fd\u662f\u6587\u4ef6\u8def\u5f84<\/strong><\/td>\u4efb\u610f io.Reader<\/code>\uff08\u6587\u4ef6\u3001\u7f51\u7edc\u3001buffer\u3001\u7ba1\u9053\u7b49\uff09<\/td><\/tr>
    \u6253\u5f00\/\u5173\u95ed\u6587\u4ef6<\/strong><\/td>\u81ea\u52a8\u5904\u7406\uff1a\u6253\u5f00 \u2192 \u8bfb\u53d6 \u2192 \u5173\u95ed<\/td>\u274c \u4e0d\u8d1f\u8d23\u6253\u5f00\/\u5173\u95ed\uff0c\u9700\u624b\u52a8\u7ba1\u7406<\/td><\/tr>
    \u9002\u7528\u8303\u56f4<\/strong><\/td>\u4e13\u7528\uff1a\u53ea\u8bfb\u6587\u4ef6<\/td>\u901a\u7528\uff1a\u53ef\u8bfb\u4efb\u4f55\u6d41\u5f0f\u6570\u636e<\/td><\/tr>
    \u8fd4\u56de\u503c<\/strong><\/td>[]byte, error<\/code><\/td>[]byte, error<\/code><\/td><\/tr>
    \u5e95\u5c42\u5b9e\u73b0<\/strong><\/td>\u5185\u90e8\u8c03\u7528 os.Open<\/code> + io.ReadAll<\/code><\/td>\u4f7f\u7528 bytes.Buffer<\/code> \u52a8\u6001\u6269\u5bb9\u8bfb\u53d6<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n
    \n\n\n\n
    \ud83e\udde9 \u56db\u3001\u5e95\u5c42\u5b9e\u73b0\u539f\u7406<\/h2>\n\n\n\n
    1. os.ReadFile<\/code> \u5904\u7406\u903b\u8f91<\/h3>\n\n\n\n
      \n
    • \u81ea\u52a8\u6253\u5f00\u548c\u5173\u95ed\u6587\u4ef6 \u2705<\/li>\n\n\n\n
    • \u5982\u679c\u80fd\u83b7\u53d6\u6587\u4ef6\u5927\u5c0f\uff0c\u4f1a\u9884\u5206\u914d buffer<\/strong>\uff0c\u51cf\u5c11\u5185\u5b58\u62f7\u8d1d<\/li>\n\n\n\n
    • \u5426\u5219 fallback \u5230 io.ReadAll<\/code><\/li>\n<\/ul>\n\n\n\n
      \n\n\n\n
      2. io.ReadAll<\/code> \u5904\u7406\u903b\u8f91<\/h3>\n\n\n\n
        \n
      • \u4f7f\u7528 bytes.Buffer<\/code> \u52a8\u6001\u6269\u5bb9<\/li>\n\n\n\n
      • \u4e0d\u77e5\u9053\u6570\u636e\u603b\u91cf\uff0c\u53ea\u80fd\u8fb9\u8bfb\u8fb9\u6269\u5bb9<\/strong><\/li>\n\n\n\n
      • \u53ef\u80fd\u53d1\u751f\u591a\u6b21\u5185\u5b58\u5206\u914d\u548c\u62f7\u8d1d\uff08\u6027\u80fd\u7565\u4f4e\uff09<\/li>\n<\/ul>\n\n\n\n
        \n\n\n\n
        \ud83d\udcc8 \u4e94\u3001\u6027\u80fd\u5bf9\u6bd4<\/h2>\n\n\n\n
        \u573a\u666f<\/th>os.ReadFile<\/code><\/th>io.ReadAll<\/code><\/th><\/tr><\/thead>
        \u5c0f\u6587\u4ef6\uff08< 1KB\uff09<\/td>\u2705 \u5feb\uff08\u9884\u5206\u914d\uff09<\/td>\u2705 \u5feb<\/td><\/tr>
        \u5927\u6587\u4ef6\uff08> 1MB\uff09<\/td>\u2705 \u66f4\u5feb\uff08\u9884\u5206\u914d\uff09<\/td>\u26a0\ufe0f \u7a0d\u6162\uff08\u52a8\u6001\u6269\u5bb9\uff09<\/td><\/tr>
        \u672a\u77e5\u957f\u5ea6\u6d41\uff08\u5982\u7f51\u7edc\uff09<\/td>\u274c \u4e0d\u9002\u7528<\/td>\u2705 \u552f\u4e00\u9009\u62e9<\/td><\/tr>
        \u5185\u5b58\u5206\u914d\u6b21\u6570<\/td>\u5c11\uff08\u53ef\u9884\u77e5\u5927\u5c0f\uff09<\/td>\u591a\uff08\u6307\u6570\u6269\u5bb9\uff09<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n
        \ud83d\udccc \u7ed3\u8bba<\/strong>\uff1a<\/p>\n\n\n\n
          \n
        • \u5982\u679c\u662f\u672c\u5730\u6587\u4ef6<\/strong>\uff0c\u4f18\u5148\u7528 os.ReadFile<\/code>\uff0c\u6027\u80fd\u66f4\u597d\u3002<\/li>\n\n\n\n
        • \u5982\u679c\u662f\u6d41\u5f0f\u6570\u636e<\/strong>\uff08\u5982 HTTP \u54cd\u5e94\u3001\u7ba1\u9053\uff09\uff0c\u5fc5\u987b\u7528 io.ReadAll<\/code>\u3002<\/li>\n<\/ul>\n\n\n\n
          \n\n\n\n
          \ud83e\uddea \u516d\u3001\u4f7f\u7528\u793a\u4f8b\u5bf9\u6bd4<\/h2>\n\n\n\n
          \u2705 \u573a\u666f1\uff1a\u8bfb\u53d6\u672c\u5730\u6587\u4ef6<\/h3>\n\n\n\n
          \/\/ \u63a8\u8350\uff1a\u4f7f\u7528 os.ReadFile\ndata, err := os.ReadFile(\"config.json\")\nif err != nil {\n    log.Fatal(err)\n}\nfmt.Println(string(data))<\/code><\/pre>\n\n\n\n
          \u2705 \u4f18\u70b9<\/strong>\uff1a\u4ee3\u7801\u7b80\u6d01\uff0c\u81ea\u52a8\u7ba1\u7406\u8d44\u6e90\uff0c\u6027\u80fd\u597d\u3002<\/p>\n\n\n\n
          \n\n\n\n
          \u2705 \u573a\u666f2\uff1a\u8bfb\u53d6 HTTP \u54cd\u5e94\u4f53<\/h3>\n\n\n\n
          resp, err := http.Get(\"https:\/\/www.madbull.site\")\nif err != nil {\n    log.Fatal(err)\n}\ndefer resp.Body.Close() \/\/ \u624b\u52a8\u5173\u95ed\uff01\n\ndata, err := io.ReadAll(resp.Body)\nif err != nil {\n    log.Fatal(err)\n}\nfmt.Println(string(data))<\/code><\/pre>\n\n\n\n
          \u274c \u4e0d\u80fd\u7528 os.ReadFile<\/code>\uff0c\u56e0\u4e3a resp.Body<\/code> \u4e0d\u662f\u6587\u4ef6\u8def\u5f84\u3002<\/p>\n\n\n\n
          \n\n\n\n
          \u2705 \u573a\u666f3\uff1a\u8bfb\u53d6\u5b57\u7b26\u4e32\u4f5c\u4e3a\u6570\u636e\u6e90<\/h3>\n\n\n\n
          reader := strings.NewReader(\"hello world\")\ndata, err := io.ReadAll(reader)\nif err != nil {\n    log.Fatal(err)\n}\nfmt.Println(string(data))<\/code><\/pre>\n\n\n\n
          os.ReadFile<\/code> \u65e0\u6cd5\u5904\u7406\u8fd9\u79cd\u60c5\u51b5\u3002<\/p>\n\n\n\n
          \n\n\n\n
          \u26a0\ufe0f \u4e03\u3001\u5e38\u89c1\u9677\u9631\u4e0e\u6ce8\u610f\u4e8b\u9879<\/h2>\n\n\n\n
          1. io.ReadAll<\/code> \u4e0d\u4f1a\u81ea\u52a8\u5173\u95ed\u8d44\u6e90\uff01<\/h3>\n\n\n\n
          resp, _ := http.Get(\"https:\/\/example.com\")\ndata, _ := io.ReadAll(resp.Body)\n\/\/ \u5fd8\u8bb0 resp.Body.Close() \u2192 \u6587\u4ef6\u63cf\u8ff0\u7b26\u6cc4\u6f0f\uff01<\/code><\/pre>\n\n\n\n
          \u2705 \u5fc5\u987b\u914d\u5408 defer resp.Body.Close()<\/code><\/p>\n\n\n\n
          \n\n\n\n
          2. os.ReadFile<\/code> \u9002\u7528\u4e8e\u5c0f\u5230\u4e2d\u7b49\u6587\u4ef6<\/h3>\n\n\n\n
          \u5bf9\u4e8e\u8d85\u5927\u6587\u4ef6<\/strong>\uff08\u5982 1GB+\uff09\uff0c\u4e24\u8005\u90fd\u4e0d\u63a8\u8350\uff0c\u5e94\u4f7f\u7528\u6d41\u5f0f\u5904\u7406<\/strong>\uff1a<\/p>\n\n\n\n
          file, _ := os.Open(\"huge.log\")\nscanner := bufio.NewScanner(file)\nfor scanner.Scan() {\n    process(scanner.Text())\n}\nfile.Close()<\/code><\/pre>\n\n\n\n
          \n\n\n\n
          3. io.ReadAll<\/code> \u53ef\u80fd OOM\uff08\u5185\u5b58\u6ea2\u51fa\uff09<\/h3>\n\n\n\n
          \u5982\u679c Reader<\/code> \u6c38\u4e0d\u8fd4\u56de EOF<\/code>\uff08\u5982\u9519\u8bef\u7684\u7f51\u7edc\u6d41\uff09\uff0cio.ReadAll<\/code> \u4f1a\u4e00\u76f4\u8bfb\uff0c\u76f4\u5230\u8017\u5c3d\u5185\u5b58\u3002<\/p>\n\n\n\n
          \u2705 \u5efa\u8bae\u914d\u5408 io.LimitReader<\/code> \u9650\u5236\u5927\u5c0f\uff1a<\/p>\n\n\n\n
          limited := io.LimitReader(resp.Body, 10<<20) \/\/ \u6700\u591a 10MB\ndata, err := io.ReadAll(limited)<\/code><\/pre>\n\n\n\n
          \n\n\n\n
          \u2705 \u516b\u3001\u5982\u4f55\u9009\u62e9\uff1f<\/h2>\n\n\n\n
          \u4f60\u7684\u9700\u6c42<\/th>\u63a8\u8350\u65b9\u6cd5<\/th><\/tr><\/thead>
          \u8bfb\u53d6\u672c\u5730\u6587\u4ef6\uff08\u914d\u7f6e\u3001\u6a21\u677f\u7b49\uff09<\/td>\u2705 os.ReadFile<\/code><\/td><\/tr>
          \u8bfb\u53d6 HTTP \u54cd\u5e94\u3001TCP \u6d41\u3001\u7ba1\u9053\u7b49<\/td>\u2705 io.ReadAll<\/code><\/td><\/tr>
          \u8bfb\u53d6 strings.Reader<\/code>\u3001bytes.Buffer<\/code><\/td>\u2705 io.ReadAll<\/code><\/td><\/tr>
          \u5927\u6587\u4ef6\u5904\u7406<\/td>\u274c \u90fd\u4e0d\u8981\u7528\uff0c\u7528 bufio.Scanner<\/code> \u6216 io.Copy<\/code> \u6d41\u5f0f\u5904\u7406<\/td><\/tr>
          \u9700\u8981\u9650\u5236\u8bfb\u53d6\u5927\u5c0f<\/td>\u2705 io.LimitReader<\/code> + io.ReadAll<\/code><\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n
          \n\n\n\n
          \ud83c\udfaf \u4e5d\u3001\u603b\u7ed3<\/h2>\n\n\n\n
          \u7279\u6027<\/th>os.ReadFile<\/code><\/th>io.ReadAll<\/code><\/th><\/tr><\/thead>
          \u7528\u9014<\/strong><\/td>\u4e13\u7528\u4e8e\u8bfb\u6587\u4ef6<\/td>\u901a\u7528\u8bfb\u53d6\u4efb\u610f Reader<\/code><\/td><\/tr>
          \u8d44\u6e90\u7ba1\u7406<\/strong><\/td>\u81ea\u52a8\u6253\u5f00\/\u5173\u95ed\u6587\u4ef6<\/td>\u9700\u624b\u52a8\u7ba1\u7406 Close()<\/code><\/td><\/tr>
          \u6027\u80fd<\/strong><\/td>\u66f4\u597d\uff08\u53ef\u9884\u5206\u914d\uff09<\/td>\u7a0d\u5dee\uff08\u52a8\u6001\u6269\u5bb9\uff09<\/td><\/tr>
          \u7075\u6d3b\u6027<\/strong><\/td>\u4f4e\uff08\u53ea\u80fd\u8bfb\u6587\u4ef6\uff09<\/td>\u9ad8\uff08\u53ef\u8bfb\u4efb\u4f55\u6d41\uff09<\/td><\/tr>
          \u63a8\u8350\u573a\u666f<\/strong><\/td>\u914d\u7f6e\u6587\u4ef6\u3001\u5c0f\u6587\u4ef6\u8bfb\u53d6<\/td>\u7f51\u7edc\u54cd\u5e94\u3001\u6d41\u5f0f\u6570\u636e<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n
          \n\n\n\n
          \ud83d\udca1 \u4e00\u53e5\u8bdd\u603b\u7ed3<\/h2>\n\n\n\n
          \n
          os.ReadFile<\/code> \u662f io.ReadAll<\/code> \u7684\u201c\u4e13\u7528\u4f18\u5316\u7248\u201d<\/strong>\uff1a
          \u5f53\u4f60\u8bfb\u6587\u4ef6<\/strong>\u65f6\uff0c\u7528 os.ReadFile<\/code>\uff1b
          \u5f53\u4f60\u8bfb\u4efb\u4f55\u5176\u4ed6\u6570\u636e\u6d41<\/strong>\u65f6\uff0c\u7528 io.ReadAll<\/code>\u3002<\/p>\n<\/blockquote>\n\n\n\n
          \u638c\u63e1\u5b83\u4eec\u7684\u533a\u522b\uff0c\u80fd\u8ba9\u4f60\u5199\u51fa\u66f4\u9ad8\u6548\u3001\u66f4\u5b89\u5168\u7684 Go \u4ee3\u7801\u3002<\/p>\n","protected":false},"excerpt":{"rendered":"
          os.ReadFile \u548c io.ReadAll \u90fd\u662f\u7528\u6765\u8bfb\u53d6\u6570\u636e\u7684\u51fd\u6570\uff0c\u4f46\u5b83\u4eec\u7684\u8bbe\u8ba1\u76ee\u6807\u3001\u4f7f\u7528\u573a\u666f\u548c\u5e95\u5c42\u884c\u4e3a […]<\/p>\n","protected":false},"author":1,"featured_media":727,"comment_status":"open","ping_status":"open","sticky":false,"template":"wp-custom-template-my","format":"standard","meta":{"footnotes":""},"categories":[286,154],"tags":[287,699],"class_list":["post-2378","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-go","category-154","tag-golang","tag-read"],"_links":{"self":[{"href":"https:\/\/www.madbull.site\/index.php?rest_route=\/wp\/v2\/posts\/2378","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.madbull.site\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.madbull.site\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.madbull.site\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.madbull.site\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=2378"}],"version-history":[{"count":2,"href":"https:\/\/www.madbull.site\/index.php?rest_route=\/wp\/v2\/posts\/2378\/revisions"}],"predecessor-version":[{"id":2387,"href":"https:\/\/www.madbull.site\/index.php?rest_route=\/wp\/v2\/posts\/2378\/revisions\/2387"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.madbull.site\/index.php?rest_route=\/wp\/v2\/media\/727"}],"wp:attachment":[{"href":"https:\/\/www.madbull.site\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=2378"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.madbull.site\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=2378"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.madbull.site\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=2378"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}