{"id":1087,"date":"2022-02-22T01:43:56","date_gmt":"2022-02-22T06:43:56","guid":{"rendered":"https:\/\/www.brunerd.com\/blog\/?p=1087"},"modified":"2022-02-25T15:23:12","modified_gmt":"2022-02-25T20:23:12","slug":"ljt-1-0-0-a-little-json-tool-for-your-shell-script","status":"publish","type":"post","link":"https:\/\/www.brunerd.com\/blog\/2022\/02\/22\/ljt-1-0-0-a-little-json-tool-for-your-shell-script\/","title":{"rendered":"ljt, a little JSON tool for your shell script"},"content":{"rendered":"\n

ljt<\/code>, the Little JSON Tool, is a concise and focused tool for quickly getting<\/strong> values from JSON and nothing else. It can be used standalone or embedded in your shell scripts. It requires only macOS 10.11+ or a *nix distro with jsc<\/a> installed. It has no other dependencies.<\/p>\n\n\n\n

You might have also seen my other project jpt<\/a>, the JSON Power Tool. It too can be used standalone or embedded in a script however its features and size (64k) might be overkill in some case and I get it! I thought the same thing too after I looked at work of Mathew Warren<\/a>, Paul Galow<\/a>, and Richard Purves<\/a>. Sometimes you don’t need to process JSON Text Sequences, use advanced JSONPath querying, modify JSON, or encode the output in a myriad of ways. Maybe all you need is something to retrieve a JSON value in your shell script.<\/p>\n\n\n\n

Where jpt was an exercise in maximalism, ljt is one of essential minimalism \u2013 or at least as minimal as this CliftonStrengths Maximizer<\/a> can go! \ud83e\udd13 The minified version is mere 1.2k and offers a bit more security and functionality than a one-liner.<\/p>\n\n\n\n

ljt<\/code> features:
\u2022 Query using JSON Pointer or JSONPath (canonical only, no filters, unions, etc)
\u2022 Javascript code injection prevention for both JSON and the query
\u2022 Multiple input methods: file redirection, file path, here doc, here string and Unix pipe
\u2022 Output of JSON strings as regular text and JSON for all others
\u2022 Maximum input size of 2GB and max output of 720MB (Note: functions that take JSON data as an environment variable or an argument are limited to a maximum of 1MB of data)
\u2022 Zero and non-zero exit statuses for success and failure, respectively<\/p>\n\n\n\n

Swing by the ljt Github<\/a> page and check it out. There are two versions of the tool one is fully commented for studying and hacking (ljt), the other is a “minified” version without any comments meant for embedding into your<\/em> shell scripts (ljt.min). The Releases<\/a> page has a macOS pkg package to install and run ljt<\/code> as a standalone utility. <\/p>\n\n\n\n

Thanks for reading and happy scripting!<\/p>\n","protected":false},"excerpt":{"rendered":"

ljt, the Little JSON Tool, is a concise and focused tool for quickly getting values from JSON and nothing else. It can be used standalone or embedded in your shell scripts. It requires only macOS 10.11+ or a *nix distro with jsc installed. It has no other dependencies. You might have also seen my other […]<\/p>\n","protected":false},"author":2,"featured_media":0,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[19,38,37,51,41,53,12,39],"tags":[],"class_list":["post-1087","post","type-post","status-publish","format-standard","hentry","category-bash","category-javascript","category-jpt","category-json","category-jsonpath","category-ljt","category-scripting","category-zsh"],"_links":{"self":[{"href":"https:\/\/www.brunerd.com\/blog\/wp-json\/wp\/v2\/posts\/1087","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.brunerd.com\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.brunerd.com\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.brunerd.com\/blog\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.brunerd.com\/blog\/wp-json\/wp\/v2\/comments?post=1087"}],"version-history":[{"count":9,"href":"https:\/\/www.brunerd.com\/blog\/wp-json\/wp\/v2\/posts\/1087\/revisions"}],"predecessor-version":[{"id":1103,"href":"https:\/\/www.brunerd.com\/blog\/wp-json\/wp\/v2\/posts\/1087\/revisions\/1103"}],"wp:attachment":[{"href":"https:\/\/www.brunerd.com\/blog\/wp-json\/wp\/v2\/media?parent=1087"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.brunerd.com\/blog\/wp-json\/wp\/v2\/categories?post=1087"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.brunerd.com\/blog\/wp-json\/wp\/v2\/tags?post=1087"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}