{"id":292,"date":"2019-10-19T04:06:13","date_gmt":"2019-10-19T04:06:13","guid":{"rendered":"https:\/\/golangbyexamples.com\/?p=292"},"modified":"2019-11-12T19:36:03","modified_gmt":"2019-11-12T19:36:03","slug":"read-large-file-word-by-word-go","status":"publish","type":"post","link":"https:\/\/golangbyexamples.com\/read-large-file-word-by-word-go\/","title":{"rendered":"Read a large file Word by Word in Go(Golang)"},"content":{"rendered":"\n<p class=\"has-medium-font-size\">When it comes to reading large files, obviously we don&#8217;t want to load the entire file in memory. bufio package in golang comes to the rescue when reading large files in Golang. Let&#8217;s say we have a sample.txt file with below contents<\/p>\n\n\n\n<pre class=\"wp-block-prismatic-blocks\"><code class=\"language-go\">This is an example\nto show how\nto read file\nword by word.<\/code><\/pre>\n\n\n\n<h2 class=\"wp-block-heading\"><strong>Word by Word scan<\/strong><\/h2>\n\n\n\n<pre class=\"wp-block-prismatic-blocks\"><code class=\"language-go\">package main\nimport (\n    \"bufio\"\n    \"fmt\"\n    \"log\"\n    \"os\"\n)\nfunc main() {\n    WordbyWordScan()\n}\nfunc WordbyWordScan() {\n    file, err := os.Open(\".\/scanner\/sample.txt\")\n    if err != nil {\n        log.Fatal(err)\n    }\n    defer file.Close()\n    scanner := bufio.NewScanner(file)\n    scanner.Split(bufio.ScanWords)\n    for scanner.Scan() {\n        fmt.Println(scanner.Text())\n    }\n    if err := scanner.Err(); err != nil {\n        log.Fatal(err)\n    }\n}<\/code><\/pre>\n\n\n\n<p class=\"has-medium-font-size\"><strong>Output:<\/strong><\/p>\n\n\n\n<pre class=\"wp-block-prismatic-blocks\"><code class=\"language-\">This\nis\nan\nexample\nto\nshow\nhow\nto\nread\nfile\nline\nby\nline\nand\nword\nby\nword.<\/code><\/pre>\n\n\n\n<p class=\"has-medium-font-size\">Please note that in the above program we set <strong>scanner.Split(bufio.ScanWords)<\/strong> which helps us to read the file word by word. Note however bufio.Scanner has max buffer size 64*1024 bytes which means in case you file has any line greater than the size of 64*1024, then it will give the error <\/p>\n\n\n\n<pre class=\"wp-block-prismatic-blocks\"><code class=\"language-go\">bufio.Scanner: token too long<\/code><\/pre>\n","protected":false},"excerpt":{"rendered":"<p>When it comes to reading large files, obviously we don&#8217;t want to load the entire file in memory. bufio package in golang comes to the rescue when reading large files in Golang&#8230;.<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"spay_email":"","footnotes":"","jetpack_publicize_message":"","jetpack_is_tweetstorm":false},"categories":[1],"tags":[],"class_list":["post-292","post","type-post","status-publish","format-standard","hentry","category-tech"],"yoast_head":"<!-- This site is optimized with the Yoast SEO plugin v22.7 - https:\/\/yoast.com\/wordpress\/plugins\/seo\/ -->\n<title>Read a large file Word by Word in Go(Golang) - 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