{"id":460,"date":"2023-10-27T19:27:50","date_gmt":"2023-10-27T19:27:50","guid":{"rendered":"https:\/\/wp-yoda.com\/en\/?post_type=notices&p=460"},"modified":"2023-10-27T19:30:03","modified_gmt":"2023-10-27T19:30:03","slug":"useful-things-in-bash","status":"publish","type":"notices","link":"https:\/\/wp-yoda.com\/en\/notices\/linux\/bash\/useful-things-in-bash\/","title":{"rendered":"Useful things in Bash"},"content":{"rendered":"\n\n\n

What is $()<\/h2>\n\n\n\n

In a shell script or terminal command, the $()<\/code> syntax is known as “command substitution.” It allows you to execute a command and use its output as part of another command or assigned to a variable. In the context of $(docker ps -q)<\/code>, it executes the docker ps -q<\/code> command and captures its output (the container IDs of running containers in this case). Therefore we can combine shell commands.<\/p>\n\n\n\n

For example, if\u00a0docker ps -q<\/code>\u00a0returns two container IDs:\u00a01234abcd<\/code>\u00a0and\u00a05678efgh<\/code>.
Using\u00a0docker stop $(docker ps -q)<\/code>\u00a0is equivalent to running\u00a0docker stop 1234abcd 5678efgh<\/code>. The command substitution allows you to dynamically pass the output of one command as an argument to another command.<\/p>\n","protected":false},"excerpt":{"rendered":"

What is $() In a shell script or terminal command, the $() syntax is known as “command substitution.” It allows you to […]<\/p>\n","protected":false},"author":1,"featured_media":0,"menu_order":0,"comment_status":"open","ping_status":"closed","template":"","format":"standard","meta":{"footnotes":""},"tags":[36,37],"notice_category":[39,38],"class_list":["post-460","notices","type-notices","status-publish","format-standard","hentry","tag-bash","tag-shellscript","notice_category-bash","notice_category-linux"],"yoast_head":"\nUseful things in Bash - WP Yoda<\/title>\n<meta name=\"robots\" content=\"index, follow, max-snippet:-1, max-image-preview:large, max-video-preview:-1\" \/>\n<link rel=\"canonical\" href=\"https:\/\/wp-yoda.com\/en\/notices\/linux\/bash\/useful-things-in-bash\/\" \/>\n<meta property=\"og:locale\" content=\"en_US\" \/>\n<meta property=\"og:type\" content=\"article\" \/>\n<meta property=\"og:title\" content=\"Useful things in Bash - WP Yoda\" \/>\n<meta property=\"og:description\" content=\"What is $() In a shell script or terminal command, the $() syntax is known as “command substitution.” It allows you to […]\" \/>\n<meta property=\"og:url\" content=\"https:\/\/wp-yoda.com\/en\/notices\/linux\/bash\/useful-things-in-bash\/\" \/>\n<meta property=\"og:site_name\" content=\"WP Yoda\" \/>\n<meta property=\"article:modified_time\" content=\"2023-10-27T19:30:03+00:00\" \/>\n<meta name=\"twitter:card\" content=\"summary_large_image\" \/>\n<meta name=\"twitter:label1\" content=\"Est. reading time\" \/>\n\t<meta name=\"twitter:data1\" content=\"1 minute\" \/>\n<script type=\"application\/ld+json\" class=\"yoast-schema-graph\">{\"@context\":\"https:\\\/\\\/schema.org\",\"@graph\":[{\"@type\":\"WebPage\",\"@id\":\"https:\\\/\\\/wp-yoda.com\\\/en\\\/notices\\\/linux\\\/bash\\\/useful-things-in-bash\\\/\",\"url\":\"https:\\\/\\\/wp-yoda.com\\\/en\\\/notices\\\/linux\\\/bash\\\/useful-things-in-bash\\\/\",\"name\":\"Useful things in Bash - 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