{"id":13541,"date":"2024-03-15T07:20:40","date_gmt":"2024-03-15T07:20:40","guid":{"rendered":"https:\/\/www.silicloud.com\/blog\/how-do-you-use-the-linux-poll-function\/"},"modified":"2025-08-05T19:57:20","modified_gmt":"2025-08-05T19:57:20","slug":"how-do-you-use-the-linux-poll-function","status":"publish","type":"post","link":"https:\/\/www.silicloud.com\/blog\/how-do-you-use-the-linux-poll-function\/","title":{"rendered":"Linux poll() Guide: Multi-Descriptor Monitoring"},"content":{"rendered":"<p>In Linux, the poll() function is used to monitor multiple file descriptors, allowing for processing when events occur. Here is how it can be used:<\/p>\n<ol>\n<li>Include header file:<\/li>\n<\/ol>\n<pre class=\"post-pre\"><code><span class=\"hljs-meta\">#<span class=\"hljs-keyword\">include<\/span> <span class=\"hljs-string\">&lt;poll.h&gt;<\/span><\/span>\r\n<\/code><\/pre>\n<ol>\n<li>Define an array of pollfd structures and initialize it.<\/li>\n<\/ol>\n<pre class=\"post-pre\"><code><span class=\"hljs-class\"><span class=\"hljs-keyword\">struct<\/span> <span class=\"hljs-title\">pollfd<\/span> <span class=\"hljs-title\">fds<\/span>[<span class=\"hljs-title\">nfds<\/span>];<\/span>\r\n<\/code><\/pre>\n<p>Among them, nfds is the number of file descriptors that need to be monitored.<\/p>\n<ol>\n<li>Set the event type and object being monitored for each file descriptor.<\/li>\n<\/ol>\n<pre class=\"post-pre\"><code>fds[i].fd = fd;           <span class=\"hljs-comment\">\/\/ \u76d1\u89c6\u7684\u6587\u4ef6\u63cf\u8ff0\u7b26<\/span>\r\nfds[i].events = events;   <span class=\"hljs-comment\">\/\/ \u76d1\u89c6\u7684\u4e8b\u4ef6\u7c7b\u578b\uff0c\u5982POLLIN\uff08\u53ef\u8bfb\uff09, POLLOUT\uff08\u53ef\u5199\uff09<\/span>\r\nfds[i].revents = <span class=\"hljs-number\">0<\/span>;       <span class=\"hljs-comment\">\/\/ \u5b9e\u9645\u53d1\u751f\u7684\u4e8b\u4ef6\u7c7b\u578b\uff0c\u7531\u7cfb\u7edf\u586b\u5145<\/span>\r\n<\/code><\/pre>\n<ol>\n<li>Use the poll() function to listen for events.<\/li>\n<\/ol>\n<pre class=\"post-pre\"><code><span class=\"hljs-type\">int<\/span> <span class=\"hljs-title function_\">poll<\/span><span class=\"hljs-params\">(<span class=\"hljs-keyword\">struct<\/span> pollfd *fds, <span class=\"hljs-type\">nfds_t<\/span> nfds, <span class=\"hljs-type\">int<\/span> timeout)<\/span>;\r\n<\/code><\/pre>\n<p>Timeout is the duration (in milliseconds) for waiting, and it can be set to -1 to indicate an infinite wait.<\/p>\n<ol>\n<li>Check the return value to determine if an event has occurred.<\/li>\n<\/ol>\n<pre class=\"post-pre\"><code><span class=\"hljs-keyword\">if<\/span> (fds[i].revents &amp; POLLIN) {\r\n    <span class=\"hljs-comment\">\/\/ \u53ef\u8bfb\u4e8b\u4ef6\u53d1\u751f\uff0c\u8fdb\u884c\u76f8\u5e94\u5904\u7406<\/span>\r\n}\r\n<span class=\"hljs-keyword\">if<\/span> (fds[i].revents &amp; POLLOUT) {\r\n    <span class=\"hljs-comment\">\/\/ \u53ef\u5199\u4e8b\u4ef6\u53d1\u751f\uff0c\u8fdb\u884c\u76f8\u5e94\u5904\u7406<\/span>\r\n}\r\n<span class=\"hljs-comment\">\/\/ \u53ef\u4ee5\u6839\u636e\u5176\u4ed6\u4e8b\u4ef6\u7c7b\u578b\u8fdb\u884c\u76f8\u5e94\u5904\u7406<\/span>\r\n<\/code><\/pre>\n<p>When the poll() function returns, the type of event that actually occurred will be filled in the revents field, and can be determined using bitwise operations.<\/p>\n<p>This is the basic usage method of the poll() function, which can be adjusted and extended according to specific needs.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>In Linux, the poll() function is used to monitor multiple file descriptors, allowing for processing when events occur. Here is how it can be used: Include header file: #include &lt;poll.h&gt; Define an array of pollfd structures and initialize it. struct pollfd fds[nfds]; Among them, nfds is the number of file descriptors that need to be [&hellip;]<\/p>\n","protected":false},"author":8,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_import_markdown_pro_load_document_selector":0,"_import_markdown_pro_submit_text_textarea":"","footnotes":""},"categories":[1],"tags":[18041,18060,297,18040,15104],"class_list":["post-13541","post","type-post","status-publish","format-standard","hentry","category-uncategorized","tag-file-descriptors","tag-i-o-monitoring","tag-linux","tag-poll-function","tag-system-programming"],"yoast_head":"<!-- This site is optimized with the Yoast SEO Premium plugin v21.5 (Yoast SEO v21.5) - https:\/\/yoast.com\/wordpress\/plugins\/seo\/ -->\n<title>Linux poll() Guide: Multi-Descriptor Monitoring - Blog - Silicon Cloud<\/title>\n<meta name=\"description\" content=\"Learn how to implement Linux poll() function for efficient file descriptor monitoring. Complete code examples and usage guide included.\" \/>\n<meta name=\"robots\" content=\"index, follow, max-snippet:-1, max-image-preview:large, max-video-preview:-1\" \/>\n<link rel=\"canonical\" href=\"https:\/\/www.silicloud.com\/blog\/how-do-you-use-the-linux-poll-function\/\" \/>\n<meta property=\"og:locale\" content=\"en_US\" \/>\n<meta property=\"og:type\" content=\"article\" \/>\n<meta property=\"og:title\" content=\"Linux poll() Guide: Multi-Descriptor Monitoring\" \/>\n<meta property=\"og:description\" content=\"Learn how to implement Linux poll() function for efficient file descriptor monitoring. Complete code examples and usage guide included.\" \/>\n<meta property=\"og:url\" content=\"https:\/\/www.silicloud.com\/blog\/how-do-you-use-the-linux-poll-function\/\" \/>\n<meta property=\"og:site_name\" content=\"Blog - Silicon Cloud\" \/>\n<meta property=\"article:publisher\" content=\"https:\/\/www.facebook.com\/SiliCloudGlobal\/\" \/>\n<meta property=\"article:published_time\" content=\"2024-03-15T07:20:40+00:00\" \/>\n<meta property=\"article:modified_time\" content=\"2025-08-05T19:57:20+00:00\" \/>\n<meta name=\"author\" content=\"William Carter\" \/>\n<meta name=\"twitter:card\" content=\"summary_large_image\" \/>\n<meta name=\"twitter:creator\" content=\"@SiliCloudGlobal\" \/>\n<meta name=\"twitter:site\" content=\"@SiliCloudGlobal\" \/>\n<meta name=\"twitter:label1\" content=\"Written by\" \/>\n\t<meta name=\"twitter:data1\" content=\"William Carter\" \/>\n\t<meta name=\"twitter:label2\" content=\"Est. reading time\" \/>\n\t<meta name=\"twitter:data2\" content=\"1 minute\" \/>\n<script type=\"application\/ld+json\" class=\"yoast-schema-graph\">{\"@context\":\"https:\/\/schema.org\",\"@graph\":[{\"@type\":\"Article\",\"@id\":\"https:\/\/www.silicloud.com\/blog\/how-do-you-use-the-linux-poll-function\/#article\",\"isPartOf\":{\"@id\":\"https:\/\/www.silicloud.com\/blog\/how-do-you-use-the-linux-poll-function\/\"},\"author\":{\"name\":\"William Carter\",\"@id\":\"https:\/\/www.silicloud.com\/blog\/#\/schema\/person\/f697031891aacefc4b681d139781d3c0\"},\"headline\":\"Linux poll() Guide: Multi-Descriptor Monitoring\",\"datePublished\":\"2024-03-15T07:20:40+00:00\",\"dateModified\":\"2025-08-05T19:57:20+00:00\",\"mainEntityOfPage\":{\"@id\":\"https:\/\/www.silicloud.com\/blog\/how-do-you-use-the-linux-poll-function\/\"},\"wordCount\":153,\"publisher\":{\"@id\":\"https:\/\/www.silicloud.com\/blog\/#organization\"},\"keywords\":[\"file descriptors\",\"I\/O monitoring\",\"Linux\",\"poll function\",\"system programming\"],\"inLanguage\":\"en-US\"},{\"@type\":\"WebPage\",\"@id\":\"https:\/\/www.silicloud.com\/blog\/how-do-you-use-the-linux-poll-function\/\",\"url\":\"https:\/\/www.silicloud.com\/blog\/how-do-you-use-the-linux-poll-function\/\",\"name\":\"Linux poll() Guide: Multi-Descriptor Monitoring - Blog - Silicon Cloud\",\"isPartOf\":{\"@id\":\"https:\/\/www.silicloud.com\/blog\/#website\"},\"datePublished\":\"2024-03-15T07:20:40+00:00\",\"dateModified\":\"2025-08-05T19:57:20+00:00\",\"description\":\"Learn how to implement Linux poll() function for efficient file descriptor monitoring. Complete code examples and usage guide included.\",\"breadcrumb\":{\"@id\":\"https:\/\/www.silicloud.com\/blog\/how-do-you-use-the-linux-poll-function\/#breadcrumb\"},\"inLanguage\":\"en-US\",\"potentialAction\":[{\"@type\":\"ReadAction\",\"target\":[\"https:\/\/www.silicloud.com\/blog\/how-do-you-use-the-linux-poll-function\/\"]}]},{\"@type\":\"BreadcrumbList\",\"@id\":\"https:\/\/www.silicloud.com\/blog\/how-do-you-use-the-linux-poll-function\/#breadcrumb\",\"itemListElement\":[{\"@type\":\"ListItem\",\"position\":1,\"name\":\"Home\",\"item\":\"https:\/\/www.silicloud.com\/blog\/\"},{\"@type\":\"ListItem\",\"position\":2,\"name\":\"Linux poll() Guide: Multi-Descriptor Monitoring\"}]},{\"@type\":\"WebSite\",\"@id\":\"https:\/\/www.silicloud.com\/blog\/#website\",\"url\":\"https:\/\/www.silicloud.com\/blog\/\",\"name\":\"Silicon Cloud Blog\",\"description\":\"\",\"publisher\":{\"@id\":\"https:\/\/www.silicloud.com\/blog\/#organization\"},\"inLanguage\":\"en-US\"},{\"@type\":\"Organization\",\"@id\":\"https:\/\/www.silicloud.com\/blog\/#organization\",\"name\":\"Silicon Cloud Blog\",\"url\":\"https:\/\/www.silicloud.com\/blog\/\",\"logo\":{\"@type\":\"ImageObject\",\"inLanguage\":\"en-US\",\"@id\":\"https:\/\/www.silicloud.com\/blog\/#\/schema\/logo\/image\/\",\"url\":\"https:\/\/www.silicloud.com\/blog\/wp-content\/uploads\/2023\/11\/EN-SILICON-Full.png\",\"contentUrl\":\"https:\/\/www.silicloud.com\/blog\/wp-content\/uploads\/2023\/11\/EN-SILICON-Full.png\",\"width\":1024,\"height\":1024,\"caption\":\"Silicon Cloud Blog\"},\"image\":{\"@id\":\"https:\/\/www.silicloud.com\/blog\/#\/schema\/logo\/image\/\"},\"sameAs\":[\"https:\/\/www.facebook.com\/SiliCloudGlobal\/\",\"https:\/\/twitter.com\/SiliCloudGlobal\"]},{\"@type\":\"Person\",\"@id\":\"https:\/\/www.silicloud.com\/blog\/#\/schema\/person\/f697031891aacefc4b681d139781d3c0\",\"name\":\"William Carter\",\"image\":{\"@type\":\"ImageObject\",\"inLanguage\":\"en-US\",\"@id\":\"https:\/\/www.silicloud.com\/blog\/#\/schema\/person\/image\/\",\"url\":\"https:\/\/secure.gravatar.com\/avatar\/1786698071dd8d74bec894b512f9e3c610c3a2a32985f67e688976cee3c8bbef?s=96&d=mm&r=g\",\"contentUrl\":\"https:\/\/secure.gravatar.com\/avatar\/1786698071dd8d74bec894b512f9e3c610c3a2a32985f67e688976cee3c8bbef?s=96&d=mm&r=g\",\"caption\":\"William Carter\"},\"url\":\"https:\/\/www.silicloud.com\/blog\/author\/williamcarter\/\"}]}<\/script>\n<!-- \/ Yoast SEO Premium plugin. -->","yoast_head_json":{"title":"Linux poll() Guide: Multi-Descriptor Monitoring - Blog - Silicon Cloud","description":"Learn how to implement Linux poll() function for efficient file descriptor monitoring. Complete code examples and usage guide included.","robots":{"index":"index","follow":"follow","max-snippet":"max-snippet:-1","max-image-preview":"max-image-preview:large","max-video-preview":"max-video-preview:-1"},"canonical":"https:\/\/www.silicloud.com\/blog\/how-do-you-use-the-linux-poll-function\/","og_locale":"en_US","og_type":"article","og_title":"Linux poll() Guide: Multi-Descriptor Monitoring","og_description":"Learn how to implement Linux poll() function for efficient file descriptor monitoring. Complete code examples and usage guide included.","og_url":"https:\/\/www.silicloud.com\/blog\/how-do-you-use-the-linux-poll-function\/","og_site_name":"Blog - Silicon Cloud","article_publisher":"https:\/\/www.facebook.com\/SiliCloudGlobal\/","article_published_time":"2024-03-15T07:20:40+00:00","article_modified_time":"2025-08-05T19:57:20+00:00","author":"William Carter","twitter_card":"summary_large_image","twitter_creator":"@SiliCloudGlobal","twitter_site":"@SiliCloudGlobal","twitter_misc":{"Written by":"William Carter","Est. reading time":"1 minute"},"schema":{"@context":"https:\/\/schema.org","@graph":[{"@type":"Article","@id":"https:\/\/www.silicloud.com\/blog\/how-do-you-use-the-linux-poll-function\/#article","isPartOf":{"@id":"https:\/\/www.silicloud.com\/blog\/how-do-you-use-the-linux-poll-function\/"},"author":{"name":"William Carter","@id":"https:\/\/www.silicloud.com\/blog\/#\/schema\/person\/f697031891aacefc4b681d139781d3c0"},"headline":"Linux poll() Guide: Multi-Descriptor Monitoring","datePublished":"2024-03-15T07:20:40+00:00","dateModified":"2025-08-05T19:57:20+00:00","mainEntityOfPage":{"@id":"https:\/\/www.silicloud.com\/blog\/how-do-you-use-the-linux-poll-function\/"},"wordCount":153,"publisher":{"@id":"https:\/\/www.silicloud.com\/blog\/#organization"},"keywords":["file descriptors","I\/O monitoring","Linux","poll function","system programming"],"inLanguage":"en-US"},{"@type":"WebPage","@id":"https:\/\/www.silicloud.com\/blog\/how-do-you-use-the-linux-poll-function\/","url":"https:\/\/www.silicloud.com\/blog\/how-do-you-use-the-linux-poll-function\/","name":"Linux poll() Guide: Multi-Descriptor Monitoring - Blog - Silicon Cloud","isPartOf":{"@id":"https:\/\/www.silicloud.com\/blog\/#website"},"datePublished":"2024-03-15T07:20:40+00:00","dateModified":"2025-08-05T19:57:20+00:00","description":"Learn how to implement Linux poll() function for efficient file descriptor monitoring. Complete code examples and usage guide included.","breadcrumb":{"@id":"https:\/\/www.silicloud.com\/blog\/how-do-you-use-the-linux-poll-function\/#breadcrumb"},"inLanguage":"en-US","potentialAction":[{"@type":"ReadAction","target":["https:\/\/www.silicloud.com\/blog\/how-do-you-use-the-linux-poll-function\/"]}]},{"@type":"BreadcrumbList","@id":"https:\/\/www.silicloud.com\/blog\/how-do-you-use-the-linux-poll-function\/#breadcrumb","itemListElement":[{"@type":"ListItem","position":1,"name":"Home","item":"https:\/\/www.silicloud.com\/blog\/"},{"@type":"ListItem","position":2,"name":"Linux poll() Guide: Multi-Descriptor Monitoring"}]},{"@type":"WebSite","@id":"https:\/\/www.silicloud.com\/blog\/#website","url":"https:\/\/www.silicloud.com\/blog\/","name":"Silicon Cloud Blog","description":"","publisher":{"@id":"https:\/\/www.silicloud.com\/blog\/#organization"},"inLanguage":"en-US"},{"@type":"Organization","@id":"https:\/\/www.silicloud.com\/blog\/#organization","name":"Silicon Cloud Blog","url":"https:\/\/www.silicloud.com\/blog\/","logo":{"@type":"ImageObject","inLanguage":"en-US","@id":"https:\/\/www.silicloud.com\/blog\/#\/schema\/logo\/image\/","url":"https:\/\/www.silicloud.com\/blog\/wp-content\/uploads\/2023\/11\/EN-SILICON-Full.png","contentUrl":"https:\/\/www.silicloud.com\/blog\/wp-content\/uploads\/2023\/11\/EN-SILICON-Full.png","width":1024,"height":1024,"caption":"Silicon Cloud Blog"},"image":{"@id":"https:\/\/www.silicloud.com\/blog\/#\/schema\/logo\/image\/"},"sameAs":["https:\/\/www.facebook.com\/SiliCloudGlobal\/","https:\/\/twitter.com\/SiliCloudGlobal"]},{"@type":"Person","@id":"https:\/\/www.silicloud.com\/blog\/#\/schema\/person\/f697031891aacefc4b681d139781d3c0","name":"William Carter","image":{"@type":"ImageObject","inLanguage":"en-US","@id":"https:\/\/www.silicloud.com\/blog\/#\/schema\/person\/image\/","url":"https:\/\/secure.gravatar.com\/avatar\/1786698071dd8d74bec894b512f9e3c610c3a2a32985f67e688976cee3c8bbef?s=96&d=mm&r=g","contentUrl":"https:\/\/secure.gravatar.com\/avatar\/1786698071dd8d74bec894b512f9e3c610c3a2a32985f67e688976cee3c8bbef?s=96&d=mm&r=g","caption":"William Carter"},"url":"https:\/\/www.silicloud.com\/blog\/author\/williamcarter\/"}]}},"_links":{"self":[{"href":"https:\/\/www.silicloud.com\/blog\/wp-json\/wp\/v2\/posts\/13541","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.silicloud.com\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.silicloud.com\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.silicloud.com\/blog\/wp-json\/wp\/v2\/users\/8"}],"replies":[{"embeddable":true,"href":"https:\/\/www.silicloud.com\/blog\/wp-json\/wp\/v2\/comments?post=13541"}],"version-history":[{"count":2,"href":"https:\/\/www.silicloud.com\/blog\/wp-json\/wp\/v2\/posts\/13541\/revisions"}],"predecessor-version":[{"id":157533,"href":"https:\/\/www.silicloud.com\/blog\/wp-json\/wp\/v2\/posts\/13541\/revisions\/157533"}],"wp:attachment":[{"href":"https:\/\/www.silicloud.com\/blog\/wp-json\/wp\/v2\/media?parent=13541"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.silicloud.com\/blog\/wp-json\/wp\/v2\/categories?post=13541"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.silicloud.com\/blog\/wp-json\/wp\/v2\/tags?post=13541"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}