`mc cat`

Table of Contents

Syntax
- Parameters
- Global Flags
Examples
Behavior
- S3 Compatibility

Syntax

The mc cat command concatenates the contents of a file or object to another file or object. You can also use the command to display the contents of the specified file or object to STDOUT. cat has similar functionality to cat.

EXAMPLE

The following command concatenates the contents of an object on a MinIO deployment to STDOUT:

mc cat play/mybucket/myobject.txt

SYNTAX

The mc cat command has the following syntax:

mc [GLOBALFLAGS] cat             \
                 [--rewind]      \
                 [--version-id]  \
                 [--encrypt-key] \
                 ALIAS [ALIAS ...]

Brackets [] indicate optional parameters.
Parameters sharing a line are mutually dependent.
Parameters seperated using the pipe | operator are mutually exclusive.

Copy the example to a text editor and modify as-needed before running the command in the terminal/shell.

You can also use mc cat against a local filesystem to produce similar results to the cat commandline tool:

Parameters

ALIAS

Required The alias of a MinIO deployment and the full path to the object. For example:

mc cat myminio/mybucket/myobject.txt

You can specify multiple objects on the same or different MinIO deployment. For example:

mc cat myminio/mybucket/object.txt myminio/myotherbucket/object.txt

For an object on a local filesystem, specify the full path to that object. For example:

mc cat ~/data/object.txt

--rewind

Optional Directs mc cat to operate only on the object version(s) that existed at specified point-in-time.

To rewind to a specific date in the past, specify the date as an ISO8601-formatted timestamp. For example: --rewind "2020.03.24T10:00".
To rewind a duration in time, specify the duration as a string in #d#hh#mm#ss format. For example: --rewind "1d2hh3mm4ss".

--rewind requires that the specified ALIAS be an S3-compatible service that supports Bucket Versioning. For MinIO deployments, use mc version to enable or disable bucket versioning.

--version-id, vid

Optional Directs mc cat to operate only on the specified object version.

--version-id requires that the specified ALIAS be an S3-compatible service that supports Bucket Versioning. For MinIO deployments, use mc version to enable or disable bucket versioning.

--encrypt-key

Encrypt or decrypt objects using server-side encryption with client-specified keys. Specify key-value pairs as KEY=VALUE.

Each KEY represents a bucket or object.
Each VALUE represents the data key to use for encrypting
object(s).

Enclose the entire list of key-value pairs passed to --encrypt-key in double quotes ".

--encrypt-key can use the MC_ENCRYPT_KEY environment variable for retrieving a list of encryption key-value pairs as an alternative to specifying them on the command line.

Global Flags

--debug

Optional

Enables verbose output to the console.

For example:

mc --debug COMMAND

--config-dir: Optional
The path to a JSON formatted configuration file that mc uses for storing data. See Configuration File for more information on how mc uses the configuration file.

--JSON

Optional

Enables JSON lines formatted output to the console.

For example:

mc --JSON COMMAND

--no-color: Optional
Disables the built-in color theme for console output. Useful for dumb terminals.

--quiet: Optional
Suppresses console output.

--insecure: Optional
Disables TLS/SSL certificate verification. Allows TLS connectivity to servers with invalid certificates. Exercise caution when using this option against untrusted S3 hosts.

--version: Optional
Displays the current version of mc.

--help: Optional
Displays a summary of command usage on the terminal.

Examples

View an S3 Object

Use mc cat to return the object:

mc cat ALIAS/PATH

Replace ALIAS with the alias of the S3-compatible host.
Replace PATH with the path to the object on the S3-compatible host.

View an S3 Object at a Point-In-Time

Use mc cat --rewind to return the object at a specific point-in-time in the past:

mc cat ALIAS/PATH --rewind DURATION

Replace ALIAS with the alias of the S3-compatible host.
Replace PATH with the path to the object on the S3-compatible host.
Replace DURATION with the point-in-time in the past at which the command returns the object. For example, specify 30d to return the version of the object 30 days prior to the current date.

Requires Versioning

mc cat requires bucket versioning to use this feature. Use mc version to enable versioning on a bucket.

View an S3 Object with Specific Version

Use mc cat --version-id to return a specific version of the object:

mc cat ALIAS/PATH --version-id VERSION

Replace ALIAS with the alias of the S3-compatible host.
Replace PATH with the path to the object on the S3-compatible host.
Replace VERSION with the specific version of the object to return.

Requires Versioning

mc cat requires bucket versioning to use this feature. Use mc version to enable versioning on a bucket.

Behavior

S3 Compatibility

The mc commandline tool is built for compatibility with the AWS S3 API and is tested MinIO and AWS S3 for expected functionality and behavior.

MinIO provides no guarantees for other S3-compatible services, as their S3 API implementation is unknown and therefore unsupported. While mc commands may work as documented, any such usage is at your own risk.