{"id":31247,"date":"2022-09-14T19:20:22","date_gmt":"2022-09-14T19:20:22","guid":{"rendered":"https:\/\/www.devopsschool.com\/blog\/?p=31247"},"modified":"2022-12-23T05:47:24","modified_gmt":"2022-12-23T05:47:24","slug":"linux-tutorials-grep-command-example","status":"publish","type":"post","link":"https:\/\/www.devopsschool.com\/blog\/linux-tutorials-grep-command-example\/","title":{"rendered":"Linux Tutorials: grep command &#038; example"},"content":{"rendered":"\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<p>Find text in a file\/files. The grep command searches through many files at a time to find a piece of text you are looking for.<\/p>\n\n\n\n<p>grep PATTERN [FILE]<\/p>\n\n\n\n<p>$ grep failed transaction.log<\/p>\n\n\n\n<p>The above command will find all of the words in the files that matched the word &#8216;failed\u2019.<\/p>\n\n\n\n<figure class=\"wp-block-image size-large\"><img loading=\"lazy\" decoding=\"async\" width=\"1024\" height=\"329\" src=\"https:\/\/www.devopsschool.com\/blog\/wp-content\/uploads\/2022\/09\/linux-grep-command-regular-expression-3-1024x329.jpg\" alt=\"\" class=\"wp-image-31248\" srcset=\"https:\/\/www.devopsschool.com\/blog\/wp-content\/uploads\/2022\/09\/linux-grep-command-regular-expression-3-1024x329.jpg 1024w, https:\/\/www.devopsschool.com\/blog\/wp-content\/uploads\/2022\/09\/linux-grep-command-regular-expression-3-300x96.jpg 300w, https:\/\/www.devopsschool.com\/blog\/wp-content\/uploads\/2022\/09\/linux-grep-command-regular-expression-3-768x247.jpg 768w, https:\/\/www.devopsschool.com\/blog\/wp-content\/uploads\/2022\/09\/linux-grep-command-regular-expression-3-1536x493.jpg 1536w, https:\/\/www.devopsschool.com\/blog\/wp-content\/uploads\/2022\/09\/linux-grep-command-regular-expression-3.jpg 1684w\" sizes=\"auto, (max-width: 1024px) 100vw, 1024px\" \/><\/figure>\n\n\n\n<figure class=\"wp-block-image size-full\"><img loading=\"lazy\" decoding=\"async\" width=\"500\" height=\"300\" src=\"https:\/\/www.devopsschool.com\/blog\/wp-content\/uploads\/2022\/09\/linux-grep-command-regular-expression-2.jpg\" alt=\"\" class=\"wp-image-31249\" srcset=\"https:\/\/www.devopsschool.com\/blog\/wp-content\/uploads\/2022\/09\/linux-grep-command-regular-expression-2.jpg 500w, https:\/\/www.devopsschool.com\/blog\/wp-content\/uploads\/2022\/09\/linux-grep-command-regular-expression-2-300x180.jpg 300w\" sizes=\"auto, (max-width: 500px) 100vw, 500px\" \/><\/figure>\n\n\n\n<p><\/p>\n\n\n\n<h2 class=\"wp-block-heading\">grep command reference and example<\/h2>\n\n\n\n<ul class=\"wp-block-list\"><li><a href=\"https:\/\/www.devopsschool.com\/commands\/tools\/linux\/grep\">https:\/\/www.devopsschool.com\/commands\/tools\/linux\/grep<\/a><\/li><li><a href=\"https:\/\/www.devopsschool.com\/blog\/unix-command-grep\/\" target=\"_blank\" rel=\"noreferrer noopener\">https:\/\/www.devopsschool.com\/blog\/unix-command-grep\/<\/a><\/li><\/ul>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n<pre class=\"wp-block-code\" aria-describedby=\"shcb-language-1\" data-shcb-language-name=\"JavaScript\" data-shcb-language-slug=\"javascript\"><span><code class=\"hljs language-javascript\">   <span class=\"hljs-number\">28<\/span>  man grep\r\n   <span class=\"hljs-number\">29<\/span>  clear\r\n   <span class=\"hljs-number\">30<\/span>  ls\r\n   <span class=\"hljs-number\">31<\/span>  more yum.log\r\n   <span class=\"hljs-number\">32<\/span>  more dmesg.old\r\n   <span class=\"hljs-number\">33<\/span>  clear\r\n   <span class=\"hljs-number\">34<\/span>  grep BIOS dmesg.old\r\n   <span class=\"hljs-number\">35<\/span>  clear\r\n   <span class=\"hljs-number\">36<\/span>  ls\r\n   <span class=\"hljs-number\">37<\/span>  grep -R error .\r\n   <span class=\"hljs-number\">38<\/span>  clear\r\n   <span class=\"hljs-number\">39<\/span>  grep -R -i error .\r\n   <span class=\"hljs-number\">40<\/span>  clear\r\n   <span class=\"hljs-number\">41<\/span>  grep -R -i error .\r\n   <span class=\"hljs-number\">42<\/span>  grep -R -i error . | grep -v BERT\r\n   <span class=\"hljs-number\">49<\/span>  grep error dmesg\r\n   <span class=\"hljs-number\">50<\/span>  grep error dmesg dmesg.old\r\n   <span class=\"hljs-number\">51<\/span>  grep error dmesg dmesg.old messages\r\n   <span class=\"hljs-number\">52<\/span>  grep -R -i error .\r\n   <span class=\"hljs-number\">54<\/span>  grep error dmesg\r\n   <span class=\"hljs-number\">55<\/span>  grep -i error dmesg\r\n   <span class=\"hljs-number\">56<\/span>  cd\r\n   <span class=\"hljs-number\">57<\/span>  ls\r\n   <span class=\"hljs-number\">58<\/span>  ls \/<span class=\"hljs-keyword\">var<\/span>\/log\/ | grep -i error\r\n   <span class=\"hljs-number\">59<\/span>  ls \/<span class=\"hljs-keyword\">var<\/span>\/log\/ | grep *.log\r\n   <span class=\"hljs-number\">60<\/span>  ls \/<span class=\"hljs-keyword\">var<\/span>\/log\/ | grep .log\r\n   <span class=\"hljs-number\">61<\/span>  ls \/<span class=\"hljs-keyword\">var<\/span>\/log\/ | grep .log | grep -v yum\r\n   <span class=\"hljs-number\">62<\/span>  cd \/<span class=\"hljs-keyword\">var<\/span>\/log\/\r\n   <span class=\"hljs-number\">63<\/span>  ls\r\n   <span class=\"hljs-number\">64<\/span>  clear\r\n   <span class=\"hljs-number\">65<\/span>  grep -o error dmesg\r\n   <span class=\"hljs-number\">66<\/span>  grep -o <span class=\"hljs-built_in\">Error<\/span> dmesg\r\n   <span class=\"hljs-number\">67<\/span>  grep <span class=\"hljs-built_in\">Error<\/span> dmesg\r\n   <span class=\"hljs-number\">68<\/span>  grep -n <span class=\"hljs-built_in\">Error<\/span> dmesg\r\n   <span class=\"hljs-number\">69<\/span>  grep -c error .\r\n   <span class=\"hljs-number\">70<\/span>  grep -c error\r\n   <span class=\"hljs-number\">71<\/span>  grep -c error *\r\n   <span class=\"hljs-number\">72<\/span>  grep -c -i error *<\/code><\/span><small class=\"shcb-language\" id=\"shcb-language-1\"><span class=\"shcb-language__label\">Code language:<\/span> <span class=\"shcb-language__name\">JavaScript<\/span> <span class=\"shcb-language__paren\">(<\/span><span class=\"shcb-language__slug\">javascript<\/span><span class=\"shcb-language__paren\">)<\/span><\/small><\/pre>\n\n\n<figure class=\"wp-block-image size-large\"><img loading=\"lazy\" decoding=\"async\" width=\"1024\" height=\"638\" src=\"https:\/\/www.devopsschool.com\/blog\/wp-content\/uploads\/2022\/09\/linux-grep-command-regular-expression-1-1024x638.jpg\" alt=\"\" class=\"wp-image-31250\" srcset=\"https:\/\/www.devopsschool.com\/blog\/wp-content\/uploads\/2022\/09\/linux-grep-command-regular-expression-1-1024x638.jpg 1024w, https:\/\/www.devopsschool.com\/blog\/wp-content\/uploads\/2022\/09\/linux-grep-command-regular-expression-1-300x187.jpg 300w, https:\/\/www.devopsschool.com\/blog\/wp-content\/uploads\/2022\/09\/linux-grep-command-regular-expression-1-768x478.jpg 768w, https:\/\/www.devopsschool.com\/blog\/wp-content\/uploads\/2022\/09\/linux-grep-command-regular-expression-1-1536x957.jpg 1536w, https:\/\/www.devopsschool.com\/blog\/wp-content\/uploads\/2022\/09\/linux-grep-command-regular-expression-1.jpg 1888w\" sizes=\"auto, (max-width: 1024px) 100vw, 1024px\" \/><\/figure>\n","protected":false},"excerpt":{"rendered":"<p>Find text in a file\/files. The grep command searches through many files at a time to find a piece of text you are looking for. grep PATTERN [FILE] $ grep failed transaction.log The above command will find all of the words in the files that matched the word &#8216;failed\u2019. grep command reference and example https:\/\/www.devopsschool.com\/commands\/tools\/linux\/grep&#8230;<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_kad_post_transparent":"","_kad_post_title":"","_kad_post_layout":"","_kad_post_sidebar_id":"","_kad_post_content_style":"","_kad_post_vertical_padding":"","_kad_post_feature":"","_kad_post_feature_position":"","_kad_post_header":false,"_kad_post_footer":false,"_kad_post_classname":"","_joinchat":[],"footnotes":""},"categories":[2],"tags":[],"class_list":["post-31247","post","type-post","status-publish","format-standard","hentry","category-uncategorised"],"_links":{"self":[{"href":"https:\/\/www.devopsschool.com\/blog\/wp-json\/wp\/v2\/posts\/31247","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.devopsschool.com\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.devopsschool.com\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.devopsschool.com\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.devopsschool.com\/blog\/wp-json\/wp\/v2\/comments?post=31247"}],"version-history":[{"count":1,"href":"https:\/\/www.devopsschool.com\/blog\/wp-json\/wp\/v2\/posts\/31247\/revisions"}],"predecessor-version":[{"id":31251,"href":"https:\/\/www.devopsschool.com\/blog\/wp-json\/wp\/v2\/posts\/31247\/revisions\/31251"}],"wp:attachment":[{"href":"https:\/\/www.devopsschool.com\/blog\/wp-json\/wp\/v2\/media?parent=31247"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.devopsschool.com\/blog\/wp-json\/wp\/v2\/categories?post=31247"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.devopsschool.com\/blog\/wp-json\/wp\/v2\/tags?post=31247"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}