Setting the output format in the AWS CLI - AWS Command Line Interface
How to select the output formatJSON output formatYAML output formatYAML stream output formatText output formatTable output format

Setting the output format in the AWS CLI

This topic describes the different output formats for the AWS Command Line Interface (AWS CLI). The AWS CLI supports the following output formats:

  • json – The output is formatted as a JSON string.

  • yaml – The output is formatted as a YAML string.

  • yaml-stream – The output is streamed and formatted as a YAML string. Streaming allows for faster handling of large data types.

  • text – The output is formatted as multiple lines of tab-separated string values. This can be useful to pass the output to a text processor, like grep, sed, or awk.

  • table – The output is formatted as a table using the characters +|- to form the cell borders. It typically presents the information in a "human-friendly" format that is much easier to read than the others, but not as programmatically useful.

How to select the output format

As explained in the configuration topic, you can specify the output format in three ways:

  • Using the output option in a named profile in the config file – The following example sets the default output format to text.

    [default]
output=text

  • Using the AWS_DEFAULT_OUTPUT environment variable – The following output sets the format to table for the commands in this command line session until the variable is changed or the session ends. Using this environment variable overrides any value set in the config file.

    $ export AWS_DEFAULT_OUTPUT="table"

  • Using the --output option on the command line – The following example sets the output of only this one command to json. Using this option on the command overrides any currently set environment variable or the value in the config file.

    $ aws swf list-domains --registration-status REGISTERED --output json
Important

The output type you specify changes how the --query option operates:

  • If you specify --output text, the output is paginated before the --query filter is applied, and the AWS CLI runs the query once on each page of the output. Due to this, the query includes the first matching element on each page which can result in unexpected extra output. To additionally filter the output, you can use other command line tools such as head or tail.

  • If you specify --output json, --output yaml, or --output yaml-stream the output is completely processed as a single, native structure before the --query filter is applied. The AWS CLI runs the query only once against the entire structure, producing a filtered result that is then output.

JSON output format

JSON is the default output format of the AWS CLI. Most programming languages can easily decode JSON strings using built-in functions or with publicly available libraries. You can combine JSON output with the --query option in powerful ways to filter and format the AWS CLI JSON-formatted output.

For more advanced filtering that you might not be able to do with --query, you can consider jq, a command line JSON processor. You can download it and find the official tutorial at http://stedolan.github.io/jq/.

The following is an example of JSON output.

$ aws iam list-users --output json
{
    "Users": [
        {
            "Path": "/",
            "UserName": "Admin",
            "UserId": "AIDA1111111111EXAMPLE",
            "Arn": "arn:aws:iam::123456789012:user/Admin",
            "CreateDate": "2014-10-16T16:03:09+00:00",
            "PasswordLastUsed": "2016-06-03T18:37:29+00:00"
        },
        {
            "Path": "/backup/",
            "UserName": "backup-user",
            "UserId": "AIDA2222222222EXAMPLE",
            "Arn": "arn:aws:iam::123456789012:user/backup/backup-user",
            "CreateDate": "2019-09-17T19:30:40+00:00"
        },
        {
            "Path": "/",
            "UserName": "cli-user",
            "UserId": "AIDA3333333333EXAMPLE",
            "Arn": "arn:aws:iam::123456789012:user/cli-user",
            "CreateDate": "2019-09-17T19:11:39+00:00"
        }
    ]
}

YAML output format

YAML is a good choice for handling the output programmatically with services and tools that emit or consume YAML-formatted strings, such as AWS CloudFormation with its support for YAML-formatted templates.

For more advanced filtering that you might not be able to do with --query, you can consider yq, a command line YAML processor. You can download yq in the yq repository on GitHub.

The following is an example of YAML output.

$ aws iam list-users --output yaml
Users:
- Arn: arn:aws:iam::123456789012:user/Admin
  CreateDate: '2014-10-16T16:03:09+00:00'
  PasswordLastUsed: '2016-06-03T18:37:29+00:00'
  Path: /
  UserId: AIDA1111111111EXAMPLE
  UserName: Admin
- Arn: arn:aws:iam::123456789012:user/backup/backup-user
  CreateDate: '2019-09-17T19:30:40+00:00'
  Path: /backup/
  UserId: AIDA2222222222EXAMPLE
  UserName: arq-45EFD6D1-CE56-459B-B39F-F9C1F78FBE19
- Arn: arn:aws:iam::123456789012:user/cli-user
  CreateDate: '2019-09-17T19:30:40+00:00'
  Path: /
  UserId: AIDA3333333333EXAMPLE
  UserName: cli-user

YAML stream output format

The yaml-stream format takes advantage of the YAML format while providing more responsive/faster viewing of large data sets by streaming the data to you. You can start viewing and using YAML data before the entire query downloads.

For more advanced filtering that you might not be able to do with --query, you can consider yq, a command line YAML processor. You can download yq in the yq repository on GitHub.

The following is an example of yaml-stream output.

$ aws iam list-users --output yaml-stream
- IsTruncated: false
  Users:
  - Arn: arn:aws:iam::123456789012:user/Admin
    CreateDate: '2014-10-16T16:03:09+00:00'
    PasswordLastUsed: '2016-06-03T18:37:29+00:00'
    Path: /
    UserId: AIDA1111111111EXAMPLE
    UserName: Admin
  - Arn: arn:aws:iam::123456789012:user/backup/backup-user
    CreateDate: '2019-09-17T19:30:40+00:00'
    Path: /backup/
    UserId: AIDA2222222222EXAMPLE
    UserName: arq-45EFD6D1-CE56-459B-B39F-F9C1F78FBE19
  - Arn: arn:aws:iam::123456789012:user/cli-user
    CreateDate: '2019-09-17T19:30:40+00:00'
    Path: /
    UserId: AIDA3333333333EXAMPLE
    UserName: cli-user

The following is an example of yaml-stream output in conjunction with using the --page-size parameter to paginate the streamed YAML content.

$ aws iam list-users --output yaml-stream --page-size 2
- IsTruncated: true
  Marker: ab1234cdef5ghi67jk8lmo9p/q012rs3t445uv6789w0x1y2z/345a6b78c9d00/1efgh234ij56klmno78pqrstu90vwxyx  
  Users:
  - Arn: arn:aws:iam::123456789012:user/Admin
    CreateDate: '2014-10-16T16:03:09+00:00'
    PasswordLastUsed: '2016-06-03T18:37:29+00:00'
    Path: /
    UserId: AIDA1111111111EXAMPLE
    UserName: Admin
  - Arn: arn:aws:iam::123456789012:user/backup/backup-user
    CreateDate: '2019-09-17T19:30:40+00:00'
    Path: /backup/
    UserId: AIDA2222222222EXAMPLE
    UserName: arq-45EFD6D1-CE56-459B-B39F-F9C1F78FBE19
- IsTruncated: false
  Users:
  - Arn: arn:aws:iam::123456789012:user/cli-user
    CreateDate: '2019-09-17T19:30:40+00:00'
    Path: /
    UserId: AIDA3333333333EXAMPLE
    UserName: cli-user

Text output format

The text format organizes the AWS CLI output into tab-delimited lines. It works well with traditional Unix text tools such as grep, sed, and awk, and the text processing performed by PowerShell.

The text output format follows the basic structure shown below. The columns are sorted alphabetically by the corresponding key names of the underlying JSON object.

IDENTIFIER  sorted-column1 sorted-column2
IDENTIFIER2 sorted-column1 sorted-column2

The following is an example of text output. Each field is tab separated from the others, with an extra tab where there is an empty field.

$ aws iam list-users --output text
USERS   arn:aws:iam::123456789012:user/Admin                2014-10-16T16:03:09+00:00   2016-06-03T18:37:29+00:00   /          AIDA1111111111EXAMPLE   Admin
USERS   arn:aws:iam::123456789012:user/backup/backup-user   2019-09-17T19:30:40+00:00                               /backup/   AIDA2222222222EXAMPLE   backup-user
USERS   arn:aws:iam::123456789012:user/cli-user             2019-09-17T19:11:39+00:00                               /          AIDA3333333333EXAMPLE   cli-user

The fourth column is the PasswordLastUsed field, and is empty for the last two entries because those users never sign in to the AWS Management Console.

Important

We strongly recommend that if you specify text output, you also always use the --query option to ensure consistent behavior.

This is because the text format alphabetically orders output columns by the key name of the underlying JSON object returned by the AWS service, and similar resources might not have the same key names. For example, the JSON representation of a Linux-based Amazon EC2 instance might have elements that are not present in the JSON representation of a Windows-based instance, or vice versa. Also, resources might have key-value elements added or removed in future updates, altering the column ordering. This is where --query augments the functionality of the text output to provide you with complete control over the output format.

In the following example, the command specifies which elements to display and defines the ordering of the columns with the list notation [key1, key2, ...]. This gives you full confidence that the correct key values are always displayed in the expected column. Finally, notice how the AWS CLI outputs None as the value for keys that don't exist.

$ aws iam list-users --output text --query 'Users[*].[UserName,Arn,CreateDate,PasswordLastUsed,UserId]'
Admin         arn:aws:iam::123456789012:user/Admin         2014-10-16T16:03:09+00:00   2016-06-03T18:37:29+00:00   AIDA1111111111EXAMPLE
backup-user   arn:aws:iam::123456789012:user/backup-user   2019-09-17T19:30:40+00:00   None                        AIDA2222222222EXAMPLE
cli-user      arn:aws:iam::123456789012:user/cli-backup    2019-09-17T19:11:39+00:00   None                        AIDA3333333333EXAMPLE

The following example shows how you can use grep and awk with the text output from the aws ec2 describe-instances command. The first command displays the Availability Zone, current state, and the instance ID of each instance in text output. The second command processes that output to display only the instance IDs of all running instances in the us-west-2a Availability Zone.

$ aws ec2 describe-instances --query 'Reservations[*].Instances[*].[Placement.AvailabilityZone, State.Name, InstanceId]' --output text
us-west-2a      running i-4b41a37c
us-west-2a      stopped i-a071c394
us-west-2b      stopped i-97a217a0
us-west-2a      running i-3045b007
us-west-2a      running i-6fc67758
$ aws ec2 describe-instances --query 'Reservations[*].Instances[*].[Placement.AvailabilityZone, State.Name, InstanceId]' --output text | grep us-west-2a | grep running | awk '{print $3}'
i-4b41a37c
i-3045b007
i-6fc67758

The following example goes a step further and shows not only how to filter the output, but how to use that output to automate changing instance types for each stopped instance.

$ aws ec2 describe-instances --query 'Reservations[*].Instances[*].[State.Name, InstanceId]' --output text |
> grep stopped |
> awk '{print $2}' |
> while read line;
> do aws ec2 modify-instance-attribute --instance-id $line --instance-type '{"Value": "m1.medium"}';
> done

The text output can also be useful in PowerShell. Because the columns in text output are tab delimited, you can easily split the output into an array by using PowerShell's `t delimiter. The following command displays the value of the third column (InstanceId) if the first column (AvailabilityZone) matches the string us-west-2a.

PS C:\>aws ec2 describe-instances --query 'Reservations[*].Instances[*].[Placement.AvailabilityZone, State.Name, InstanceId]' --output text |
%{if ($_.split("`t")[0] -match "us-west-2a") { $_.split("`t")[2]; } }
-4b41a37c
i-a071c394
i-3045b007
i-6fc67758

Notice that although the previous example does show how to use the --query parameter to parse the underlying JSON objects and pull out the desired column, PowerShell has its own ability to handle JSON, if cross-platform compatibility isn't a concern. Instead of handling the output as text, as most command shells require, PowerShell lets you use the ConvertFrom-JSON cmdlet to produce a hierarchically structured object. You can then directly access the member you want from that object.

(aws ec2 describe-instances --output json | ConvertFrom-Json).Reservations.Instances.InstanceId
Tip

If you output text, and filter the output to a single field using the --query parameter, the output is a single line of tab-separated values. To get each value onto a separate line, you can put the output field in brackets, as shown in the following examples.

Tab separated, single-line output:

$ aws iam list-groups-for-user --user-name susan  --output text --query "Groups[].GroupName"
HRDepartment    Developers      SpreadsheetUsers  LocalAdmins

Each value on its own line by putting [GroupName] in brackets:

$ aws iam list-groups-for-user --user-name susan  --output text --query "Groups[].[GroupName]"
HRDepartment
Developers
SpreadsheetUsers
LocalAdmins

Table output format

The table format produces human-readable representations of complex AWS CLI output in a tabular form.

$ aws iam list-users --output table
-----------------------------------------------------------------------------------------------------------------------------------------------------------------
|                                                                                 ListUsers                                                                     |
+---------------------------------------------------------------------------------------------------------------------------------------------------------------+
||                                                                                  Users                                                                      ||
|+----------------------------------------------------+---------------------------+---------------------------+----------+-----------------------+-------------+|
||                         Arn                        |       CreateDate          |    PasswordLastUsed       |   Path   |        UserId         |   UserName  ||
|+----------------------------------------------------+---------------------------+---------------------------+----------+-----------------------+-------------+|
||  arn:aws:iam::123456789012:user/Admin              | 2014-10-16T16:03:09+00:00 | 2016-06-03T18:37:29+00:00 | /        | AIDA1111111111EXAMPLE | Admin       ||
||  arn:aws:iam::123456789012:user/backup/backup-user | 2019-09-17T19:30:40+00:00 |                           | /backup/ | AIDA2222222222EXAMPLE | backup-user ||
||  arn:aws:iam::123456789012:user/cli-user           | 2019-09-17T19:11:39+00:00 |                           | /        | AIDA3333333333EXAMPLE | cli-user    ||
+---------------------------------------------------------------------------------------------------------------------------------------------------------------+

You can combine the --query option with the table format to display a set of elements preselected from the raw output. Notice the output differences between dictionary and list notations: in the first example, column names are ordered alphabetically, and in the second example, unnamed columns are ordered as defined by the user. For more information about the --query option, see Filtering output in the AWS CLI.

$ aws ec2 describe-volumes --query 'Volumes[*].{ID:VolumeId,InstanceId:Attachments[0].InstanceId,AZ:AvailabilityZone,Size:Size}' --output table
------------------------------------------------------
|                   DescribeVolumes                  | 
+------------+----------------+--------------+-------+
|     AZ     |      ID        | InstanceId   | Size  |
+------------+----------------+--------------+-------+
|  us-west-2a|  vol-e11a5288  |  i-a071c394  |  30   |
|  us-west-2a|  vol-2e410a47  |  i-4b41a37c  |  8    |
+------------+----------------+--------------+-------+
$ aws ec2 describe-volumes --query 'Volumes[*].[VolumeId,Attachments[0].InstanceId,AvailabilityZone,Size]' --output table
----------------------------------------------------
|                  DescribeVolumes                 |
+--------------+--------------+--------------+-----+
|  vol-e11a5288|  i-a071c394  |  us-west-2a  |  30 |
|  vol-2e410a47|  i-4b41a37c  |  us-west-2a  |  8  |
+--------------+--------------+--------------+-----+