{"id":1626,"date":"2024-10-28T11:30:13","date_gmt":"2024-10-28T03:30:13","guid":{"rendered":"https:\/\/www.madbull.site\/?p=1626"},"modified":"2024-10-29T09:43:30","modified_gmt":"2024-10-29T01:43:30","slug":"offset%e8%8e%b7%e5%8f%96%e7%bb%93%e6%9e%84%e4%bd%93%e6%88%90%e5%91%98%e5%8f%98%e9%87%8f","status":"publish","type":"post","link":"https:\/\/www.madbull.site\/?p=1626","title":{"rendered":"offsetof\u83b7\u53d6\u7ed3\u6784\u4f53\u6210\u5458\u53d8\u91cf"},"content":{"rendered":"\n<p class=\"has-large-font-size\"><strong>\u4ee3\u7801\uff1a<\/strong><\/p>\n\n\n\n<div style=\"margin-top:var(--wp--preset--spacing--20);margin-bottom:var(--wp--preset--spacing--20);height:0px\" aria-hidden=\"true\" class=\"wp-block-spacer\"><\/div>\n\n\n\n<pre class=\"wp-block-code\"><code>\/\/ gcc -Wall -o t t.c \n\n#include &lt;stdio.h&gt;\n#include &lt;stddef.h&gt;\n\nstruct Person {\n    char name&#91;50];\n    int age;\n    double score;\n};\n\nint main() {\n    \/\/ \u83b7\u53d6\u7ed3\u6784\u4f53\u6210\u5458\u7684\u504f\u79fb\u91cf\n    size_t offset_name = <mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-accent-3-color\"><strong>offsetof<\/strong><\/mark>(struct Person, name);\n    size_t offset_age = <mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-accent-3-color\"><strong>offsetof<\/strong><\/mark>(struct Person, age);\n    size_t offset_score = <mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-accent-3-color\"><strong>offsetof<\/strong><\/mark>(struct Person, score);\n\n    printf(\"Offset of name: %zu\\n\", offset_name);\n    printf(\"Offset of age: %zu\\n\", offset_age);\n    printf(\"Offset of score: %zu\\n\", offset_score);\n\n    struct Person prsn = {\"Lilei\", 12, 99}  ;\n\n    char * name = <mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-accent-3-color\"><strong>(char *)((char*)&amp;prsn + offset_name)<\/strong><\/mark> ;\n    int * age= <mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-accent-3-color\"><strong>(int*)((char*)&amp;prsn + offset_age)<\/strong><\/mark> ;\n    double * score = <mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-accent-3-color\"><strong>(double *)((char*)&amp;prsn + offset_score)<\/strong><\/mark> ;\n\n\n    printf(\"name  : %s\\n\", name) ;\n    printf(\"age   : %d\\n\", *age) ;\n    printf(\"score : %f\\n\", *score) ;\n\n    return 0;\n}<\/code><\/pre>\n\n\n\n<div style=\"margin-top:var(--wp--preset--spacing--20);margin-bottom:var(--wp--preset--spacing--20);height:0px\" aria-hidden=\"true\" class=\"wp-block-spacer\"><\/div>\n\n\n\n<p class=\"has-large-font-size\"><strong>\u6d4b\u8bd5\uff1a<\/strong><\/p>\n\n\n\n<div style=\"margin-top:var(--wp--preset--spacing--20);margin-bottom:var(--wp--preset--spacing--20);height:0px\" aria-hidden=\"true\" 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\u6d4b\u8bd5\uff1a<\/p>\n","protected":false},"author":1,"featured_media":559,"comment_status":"open","ping_status":"open","sticky":false,"template":"single-with-sidebar","format":"standard","meta":{"footnotes":""},"categories":[156,154],"tags":[175,522,523],"class_list":["post-1626","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-c-c","category-154","tag-c","tag-offset","tag-offsetof"],"_links":{"self":[{"href":"https:\/\/www.madbull.site\/index.php?rest_route=\/wp\/v2\/posts\/1626","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=1626"}],"version-history":[{"count":3,"href":"https:\/\/www.madbull.site\/index.php?rest_route=\/wp\/v2\/posts\/1626\/revisions"}],"predecessor-version":[{"id":1631,"href":"https:\/\/www.madbull.site\/index.php?rest_route=\/wp\/v2\/posts\/1626\/revisions\/1631"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.madbull.site\/index.php?rest_route=\/wp\/v2\/media\/559"}],"wp:attachment":[{"href":"https:\/\/www.madbull.site\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=1626"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.madbull.site\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=1626"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.madbull.site\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=1626"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}