Jq append to file. json appends a new object to the array from feed.

Jq append to file. 6, 1. Oct 29, 2023 · In the following blog post learn how to use jq to transform multiple JSON data files into a single file. Here's a bash solution which captures the output using $() and provides it for the next using <<<. In the following example, we create several new elements. json|sponge test. The += operator is used to append an element, and the element we’re appending is "element". json file but doing so results in the following error from both jq commands: jq: invalid JSON text passed to --argjson May 7, 2023 · It's not really append what I'm looking for but because I had future noobs in mind, I took the liberty of including it in the title. How can I format strings inside jq similar to printf like padding (%4s). See below for "wrong output" produced. Sep 22, 2025 · In this comprehensive article, you will use jq to transform a sample JSON file about ocean animals, then progress to advanced techniques including AI integration, performance optimization, and real-world production scenarios. Feb 28, 2021 · Use --argjson rather than --arg when passing JSON rather than strings. json, you could write: jq '. append() method inserts the specified content as the last child of each element in the jQuery collection (To insert it as the first child, use . But the following also doesn't work. After working on this project further I realized everything will be much simpler if I store the data as json rather than plain text. jq. A jq program is a "filter": it takes an input, and produces an output. last' The above works when both first and last are string. I have the first part working curl -s -u "admin:admin" -H "X-Reque Downloading jQuery There are two versions of jQuery available for downloading: Production version - this is for your live website because it has been minified and compressed Development version - this is for testing and development (uncompressed and readable code) Both versions can be downloaded from jQuery. Add Key-Value Pair Mar 19, 2023 · Adding a new element to an existing JSON array can be completed using jq. prepend()). In general, the jq command is a very concise way of adding an object to an existing JSON object. users[] | . I've got 2 json files and want to merge them into one unique file Here the content of files: file1 { &quot;value1&quot; jq, realtime output to file EDIT: Solved, will post solution after dinner. json (e. Add Several New Elements With after () and before () Also, both the after() and before() methods can take an infinite number of new elements as parameters. 3 or development version. Oct 15, 2023 · Before using jq, you may need to pre-process the text. I am looking to search for/capture a line-ending " and a ] in the next line (end of file) in json files (many of them). You’ll apply data transformations using filters, merge pieces of transformed data into new data structures, and learn how to integrate jq into modern AI and DevOps Oct 28, 2015 · Add a field to an object with JQ. For example, how can I force number to occupy 1 Oct 10, 2023 · Continue to help good content that is interesting, well-researched, and useful, rise to the top! To gain full voting privileges, Jun 10, 2023 · Supposing you only want the modified item to be added to the array in sub_meta. json: You can load full_meta. json contains exactly one array (or the JSON value null). md file in this case) into it using jq, before updating the same object using a PUT call. I'm u Nov 15, 2023 · This is jq’s syntax for adding an element to an array. As you may already know, jq provides this capability. json. So to start, you could initialize output. json), and append it to output. json | jq ". There are a lot of builtin filters for extracting a particular field of an object, or converting a number to a string, or various other standard tasks. json appends a new object to the array from feed. I've experimented with unique, has, not, etc. Sep 29, 2019 · What is jq? I use jq when I need a quick way to gain insights on JSON in the command line. results[] | select(. This essentially automates the process of calling jq on the file multiple times Jan 17, 2021 · Been struggling with this for a while and I'm no closer to a solution. g. 7, 1. Each object will be the following except the contact_group inside each array (1-5) will vary: { &quot;contact_g May 12, 2022 · You don't capture the output of an iteration step, so you lose the output from the jq call and start all over again in the next iteration step. c. Apr 3, 2018 · You'll need to complete a few actions and gain 15 reputation points before being able to upvote. tmp is redirecting the output of jq into a temporarily file. id == "1") | {name}' # get result with multiple filters $ cat file. @mgalgs I found myself wanting to generate/use jq at the start of a shell pipeline rather than in the middle/end for filtering down on some data. I tired to use jq Jun 8, 2022 · It's just appending, and not taking into account markdown styles such as ### which would bold text. It could either be a one-line command or a bash script. name="a"))' # filter with substrings Learn how to append to an array in jQuery with this easy-to-follow guide. Jul 20, 2021 · jq has built-in ability to convert numbers to string or concatenate strings. Further, the input data may need to be presented with a slightly different structure than the original. Jan 18, 2020 · If you wanted simply to append the objects in File_1. Don‘t be afraid to explore more advanced functionality as you gain experience with jq. ” This post will provide examples of how jq can help you answer questions about JSON. Referring to solution on this question. What's reputation and how do I get it? Instead, you can save this post to reference later. json file that looks like this: [ { &quot;array&quot;: [ &quot;string1&quot;, &quot;string2&quot; ] }, { &quot;object1&quot;: { &quot;subobject1&qu Use jq again to select from the original log file only those parts of the data you want and write it to its own file. We’ll begin by understanding the problem and then work our way down to several possible solutions. Continue reading for a more detailed guide, complete with code examples and explanations. I'd like to take the values from one json file and add them to another file when other valu Jul 3, 2018 · Yes it is, provided you add a comma on line 8 after the closing bracket } (otherwise jq won't parse your input JSON data): Oct 28, 2025 · jq Cheet Sheet. allowed_users + [ "test2" ]' it will add a new entry there but the rest of the file is lost so I can't recreate the configuration file again. Supports nested JSON and large datasets. sudo echo "something" >> /etc/config_file Is there a way to append to a file in that situation without having to first open it with a sudo 'd editor and then appending the new content by hand? Sep 27, 2016 · I am trying to curl some URL which returns a json file, then I want to parse hosts from it and create a comma separated string. Jul 26, 2024 · Learn ways to handle and generate a nested JSON configuration from dynamic variables in Linux. number Mar 23, 2022 · Is QJ able to output its result directly to a file without using redirection of STDOUT? I need to use it from Windows Registry entry for JSON files context menu. Concatenating fields in JQ with examplesHow to concatenate 2 fields in JSON using JQ Suppose you have the following JSON input: Feb 5, 2019 · You'll need to complete a few actions and gain 15 reputation points before being able to upvote. Nov 7, 2019 · Explore the capabilities that jq provides for processing and manipulating JSON via the command line. 4, 1. json File_1. another tv:lcd mount: field1:field1 field2:field2 . an object originating from file input_01. The elements are created with text Jan 27, 2022 · I have a json as mentioned in the first section and i want to add an element ("image": "<IMAGE1_NAME>",) in the json as specified in the expected output. cat manifest. Feb 12, 2018 · Using jq, how can I take a json object from a file (input_02. But there’s so much more to learn about handling arrays in jq. In this how-to guide, we have learned to use the JQ command to organize and filter JSON data. json for example which contains a JSON array. 2. Jeremy's interwebs free knowledge base, a collection of everything I learned doing IT. mv feed. Jun 12, 2023 · I know how to use jq on a single file, but would like to automate this for the list of files and produce the above output if this is possible. The new elements can be generated with text/HTML (like we have done in the example above), with jQuery, or with JavaScript code and DOM elements. (Note that there are better ways to solve this problem, e. address = "abcde"' test. For that purpose, we’ll make use of the jq utility. json Add a comment Show 3 more jq 1. I'm not very experienced using jq. Strings are added by being joined into a larger string. Learn practical workflows, common use cases, and solutions to real-world challenges when working with YAML configuration files. echo "something" >> /etc/config_file But, since only the root user has write permission to this file, I can't do that. |: This pipe symbol directs the output of the cat command into jq for further processing. json, you might like Apr 10, 2025 · Learn how to merge multiple JSON files into one using our free online tool, Python scripts, JavaScript, and command-line jq. appendTo(), on the other hand, the content precedes the method, either as a selector expression or as markup created on May 30, 2013 · The whole idea was we wanted to append to a son file. json In a chain of pipes You’ll probably want to use the -r (raw) command if you’re using it in a pipeline or saving the output to a variable. "Unix & Linux StackExchange" is a good place Nov 25, 2018 · jq and jmespath are different languages/tools. Mar 18, 2024 · In this tutorial, we’ll discuss how to add a JSON object to a JSON array in another file. The jQuery library is a single JavaScript file, and you reference it with the HTML Jun 22, 2024 · Restructure JSON Objects Using jq June 22, 2024 You may encounter a scenario in which you want to produce JSON with a subset of data from an input of JSON. Jan 3, 2020 · The above is what I want to append. Mar 18, 2024 · The jq command is a lightweight and flexible command-line JSON processor. I dont know how to handle jq to create json file. 8, 1. > feed. Includes examples and code snippets. here is the json file: Apr 7, 2025 · A comprehensive guide to using YQ, a powerful command-line tool for parsing and manipulating YAML files. Append content using a function Using a function to insert content at the end of the selected elements. Even if you delete "age":23, you still get "invalid numeric literal". jq '. Nov 11, 2023 · The jq command is a powerful JSON processor for querying and manipulating JSON data from the command line. Summary – Master JSON Processing with JQ In this comprehensive guide, we‘ve seen how jq enables powerful manipulation of JSON directly from the comfort of the command line. json is replacing original file with the new temporarily file. Basically I want to iterate over list of urls, populate 2 variables and push it to results. According to the jq manual, “a jq program is a “filter”: it takes an input, and produces an output. 5, 1. The curl example is a basic one, but I found myself frequently hand typing in JSON data to curl and trying to get quoting right, so I thought it might be useful to others as well. I am still a bash/jq noob so detailed explanations are appreciated. May 12, 2021 · I haved tried just removing the brackets from the inpur. json If you want to take the risk and overwrite output. I have this command which creates JSON objects from eac Oct 17, 2012 · If the contents are in a file and you want to modify this file permanently, use a in-place edit tool like sponge available from GNU moreutils package which you can do Feb 24, 2018 · Append to array in json file from another json file with "jq" Asked 7 years, 1 month ago Modified 5 years, 4 months ago Viewed 8k times The . Seems like you're using jq - you might want to change this question a little (and use the jq website for reference!). The major difference is in the syntax-specifically, in the placement of the content and target. -r gets rid of formatting like quotes and spaces for single values. Jul 27, 2021 · Is that possible with jq somehow? I have tried cat file. Basically updating the original file with the new content. com. js Jan 17, 2022 · here I want to append another json object just before c block by searching, basically appending the value just before last object, in this case last object will always be c Jun 1, 2023 · How exactly does the file "hold" the objects? is there an outer structure such as an array, or are they simply concatenated as shown in your example? $ cat file. json | sed G | jq . ) json='{"input Jul 21, 2022 · Append a string to the output of jq Asked 3 years, 2 months ago Modified 3 years, 2 months ago Viewed 1k times Jan 12, 2023 · I want to add a value to a json text, but jq '. without success and actually I wanted to avoid some sed magic thinking that maybe jq could do all the work. (It's also helpful to stay in the habits necessary to write portable code; the whole reason I dropped zsh after spending 6 months learning it back in the mid-2000s is that my Aug 5, 2020 · Nice!) From a JSON file Just pass the file path after the jq script. json file: @supersize This answer actually works for me, because it captures the jq output and echos it to the file, where redirecting the jq output directly to the file was failing ssi-anik Over a year ago I have tried like this and it worked. For example. json file as entry/per iteration. json to an existing array in (say) output. . 1. GitHub Gist: instantly share code, notes, and snippets. Get started today and boost your productivity! Jan 20, 2021 · There are quite a lot of "how do I merge two JSON files with jq?" already in our knowledge base, though granted many are more complex than this case -- it did take some looking to find one that was a perfect fit. Mar 16, 2017 · I also considered a sed workaround that trimmed the last line of the file and then appended the new keypair (and EOF) but of course sed doesn't play well with newlines and I can't get it to work. Add element to existing array of objects using jq This is a generic projects. Oct 3, 2020 · $ cat file file file | mlr --j2c -N unsparsify --fill-with null -f status,city,gender then cut -o -f status,city,gender active,null,male active,null,male active,null,male This uses Miller (mlr) to read the JSON in the question three times in a row. The add() function in JQ allows us to concatenate multiple JSON arrays. For example, the line below is exactly what the command above is appending during a test run Nov 8, 2023 · Now I need to append to the file that already exists keeping the same structure xxxx: service:ser1 image: field1:field1 field2:field2 . json | jq '. It plays nice with UNIX pipes and offers extensive functionality for interrogating, manipulating and working with JSON file. json as input, append the modification to it, write the result into a temporary file, and if all was successful, replace the old sub_meta. Jan 12, 2021 · Add key/value to json object Ask Question Asked 4 years, 9 months ago Modified 2 years, 7 months ago Mar 18, 2024 · The jq command is a lightweight and flexible command-line JSON processor. Some key takeaways: Sep 26, 2019 · Continue to help good content that is interesting, well-researched, and useful, rise to the top! To gain full voting privileges,. json, while retaining everything already in output. Hi, This is somewhat related to a question I posted the other day. Jul 23, 2021 · I have a test. Each time it starts by filling in any empty or missing values in the fields status, city, or gender with the string null using the unsparsify Aug 5, 2016 · jq is a fantastic command-line JSON processor. Any tips on how to pipe correctly to jq and assemble the output would be great Mar 17, 2024 · How to Read JSON Array from File to Convert into Bash Array To read a JSON array from a file and convert it into a Bash array, just use the “jq” command which will parse the JSON data from the specified file and assign the parsed elements to an array in Bash. append() and . Jun 6, 2025 · A comprehensive jq cheat sheet for using jq with files and pipes, including syntax, arguments, selectors, and key functions like keys, length, flatten, and unique. 4. May 10, 2024 · 0 I want to add \t before each element in the resulting jq array and this is for formatting purposes as the result will get added to a file. Nov 20, 2024 · Here are some examples of using the jq command-line utility to create new JSON data from scratch or update values in an existing JSON document. version |= \"${VERSION}\"" --indent 4 | tee manifest. Dec 15, 2021 · 2 This question already has answers here: Add new element to existing JSON array with jq (4 answers) When to wrap quotes around a shell variable? (4 answers) Nov 7, 2022 · {key:value} I want the AWS secrets CLI command output (secretstring json object) { user:name, pass:word } to be appended to my JSON file above so that the file now becomes { key:value, user:name, pass:word } I tried jq but it just overwrites my json file with the command output with \ as escape characters for quotes. In this article, we’ll explore 15 advanced techniques and practical examples for mastering JSON transformation with jq I'm using the jq tools (jq-json-processor) in shell script to parse json. My json file is formatted like so: Aug 23, 2015 · I'm adding strings to a JSON array using jq, and it works great, but I'd like to only add strings that do not already exist. Feb 26, 2020 · My goal is to output a JSON object using jq on the output of a find command in bash. id == "1") and (. tmp feed. MacOS: On MacOS, you can use Homebrew to install jq: AFAIK jq does not support in-place editing, so you must redirect to a temporary file first and then replace your original file with it, or use sponge utility from the moreutils package, like that: jq '. += [{}]' feed. jq_path +{"key":"value"}' will only output that section and jq '. json file with the new (temporary You'll need to complete a few actions and gain 15 reputation points before being able to upvote. jq -s add keeps giving "parse error: Invalid numeric literal at line 3, column 32". +{jq_path:{"key":"value"}}' will replace all that is written within the section to which the path points (here described as jq_path). jq: The --from-file option allows jq to read and execute jq expressions stored in a separate file pointed to by path/to/script. append () - Create content with HTML, jQuery and DOM Insert content with the append () method. The information below cover merging items with different array labels. Upvoting indicates when questions and answers are useful. Jul 30, 2018 · I am trying to use bash to create a string variable that will be used in jq to add new elements to the json file. But it's escaping my double quote. I have written a script to retrieve certain value from file. json: This command reads out the JSON file’s content, preparing it for piping. I am expe Jul 20, 2020 · You'll need to complete a few actions and gain 15 reputation points before being able to upvote. It works if I provide the value to jq select, but the variable doesn't seem to work (or I don't know how to use it). first + " " + . The . Jan 27, 2015 · You can use addition to concatenate strings. 8 Manual For other versions, see 1. json There are other techniques to "redirect to the same file", like saving your output in a variable e. Convert Text to JSON: Once the text file is cleaned up, you can use jq to convert it into a JSON object. #!/bin/sh #t Oct 22, 2022 · This solution is shown as an example in the documentation for jq - see man jq and search for with_entries - but as it's a reference document it can be hard to find things you don't know how to describe. json by running: echo null > output. Oct 24, 2023 · The jq manual covers the complete syntax and capabilities. Dec 17, 2024 · cat path/to/file. + [inputs]' output. appendTo() methods perform the same task. jq is written in the C programming language and is completely portable to other systems, with no runtime dependencies. With . In this comprehensive guide, we will explore 15 practical examples of using jq in Linux to give you a solid […] Apr 12, 2016 · You'll need to complete a few actions and gain 15 reputation points before being able to upvote. name' package. Remove any unwanted characters, control characters, or tabs that might interfere with the JSON parsing. I'm missing a piece or two Dec 5, 2018 · I'm trying to generate a json array of objects dynamically from a URL and save the array to a file. access. txt file to ensure it's properly formatted for conversion to JSON. Filters can be combined in various ways - you can pipe the output of one filter Mar 10, 2017 · I'm trying to use take a JSON object from a REST API GET call, then add the contents of a raw file (. It can be used to slice, filter, and transform the components of a JSON file. It takes an array of arrays as its argument and returns a single array containing all the elements from the input arrays. first + " " + (. append(), the selector expression preceding the method is the container into which the content is inserted. If I use jq '. results[] | select((. json as a variable, modify it as you see fit, read sub_meta. json This presupposes output. Jun 22, 2022 · 0 I was trying to write a query in linux for alternate a json file and write it in a new file. jq --from-file path/to/script. It allows filtering, mapping, sorting, limiting, and other operations on JSON in a simple and efficient way. without looping but by proving jq all elements to be added at once. Add Key-Value Pair Aug 7, 2018 · That is, jq reads an object/value in from the file and executes the pipeline on it, and anywhere input appears the next input is read in and is used as the result of the function. I'm open to solutions that use anything in bash and anything in jq. t. This post describes a specific scenario where you need to map from the values of Jan 14, 2024 · Windows: For Windows, download the executable from the jq official website and add it to your system's PATH. Is it possible to pipe curls output to jq modify the curl json object and then append it to a jso Oct 8, 2023 · JSON manipulation is a common task for developers and data professionals. Step-by-step guide for developers and data engineers. I have some JSON objects that I need to add a value to if it doesn't already exist. Take the file data. Jul 3, 2021 · jq How to add an object in a file to an array in a file Ask Question Asked 4 years, 4 months ago Modified 4 years, 4 months ago Feb 16, 2023 · How to add a key value pair into a JSON file with JQ? Ask Question Asked 2 years, 8 months ago Modified 2 years, 8 months ago Also note that jq does not do in-place editing, which means you will need to redirect the output of the above command to a new name and then replace the original file with that new file. The Problem Jun 18, 2020 · how to add an object to existing json file using jq Asked 5 years, 4 months ago Modified 3 years, 6 months ago Viewed 3k times '. com - under mazda string ( while X is the ID number ) we need to update the json file on our Apr 26, 2025 · The JQ command is built around filters which are used to find and print only the required data from a JSON file. If you are extracting different datatypes (number and string), then we need to convert to equivalent types. Mar 18, 2023 · Learn how to make a jq program reusable by passing Bash variables to it. Nov 27, 2019 · We want to edit the json file according to the following rule We need to generate the name car0X_hyb. When in doubt, quote your strings; that way if the shell executing your code isn't the one you think it is, you won't have your values being munged. 2hu4nu0fq af hi duy01 spn bu 9yjz qeh omm s3x