mc cat
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.
The following command concatenates the contents of an object on a MinIO deployment to STDOUT:
mc cat play/mybucket/myobject.txt
The mc cat command has the following syntax:
mc [GLOBALFLAGS] cat \
ALIAS [ALIAS ...] \
[--enc-c "value"] \
[--offset "int"] \
[--part-number "int"] \
[--rewind] \
[--tail "int"] \
[--version-id "string"] \
[--zip]
- Brackets
[]indicate optional parameters. - Parameters sharing a line are mutually dependent.
- Parameters separated 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
mc-cmd
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
--enc-c
mc-cmd
Optional
Encrypt or decrypt objects using server-side SSE-C encryption with client-managed keys.
The parameter accepts a key-value pair formatted as KEY=VALUE
| The full path to the object as You can specify only the top-level path to use a single encryption key for all operations in that path. |
| Specify either a 32-byte RawBase64-encoded key or a 64-byte hex-encoded key for use with SSE-C encryption. Raw Base64 encoding rejects |
KEY- the full path to the object asalias/bucket/path/object.VALUE- the 32-byte RAW Base64-encoded data key to use for encrypting object(s).
For example:
# RawBase64-Encoded string "mybucket32byteencryptionkeyssec"
--enc-c "myminio/mybucket/prefix/object.obj=bXlidWNrZXQzMmJ5dGVlbmNyeXB0aW9ua2V5c3NlYwo"
You can specify multiple encryption keys by repeating the parameter.
Specify the path to a prefix to apply encryption to all matching objects at that path:
--enc-c "myminio/mybucket/prefix/=bXlidWNrZXQzMmJ5dGVlbmNyeXB0aW9ua2V5c3NlYwo"
Note
MinIO strongly recommends against using SSE-C encryption in production workloads. Use SSE-KMS via the --enc-kms or SSE-S3 via --enc-s3 parameters instead.
--offset
mc-cmd
Optional
Specify an integer that is the number of bytes from which the command offsets the output.
Mutually exclusive with the --part-number flag.
--part-number
mc-cmd
Optional
Download a specific part number of a multi-part upload. Specify the integer of the part number to download.
Mutually exclusive with the --offset and --tail flags.
--rewind
mc-cmd
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#ssformat. 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.
--tail
mc-cmd
Optional
Specify an integer that is the number of bytes from which the command trims the output.
Mutually exclusive with the --part-number flag.
--version-id, vid
mc-cmd
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.
--zip
mc-cmd
Optional
Extracts the contents from a zip file on the source to the remote. Requires a MinIO deployment as the source ALIAS.
Global Flags
This command supports any of the global flags.
Examples
View an S3 Object
Use mc cat to return the object:
mc cat ALIAS/PATH
- Replace
ALIASwith thealiasof the S3-compatible host. - Replace
PATHwith 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
ALIASwith thealiasof the S3-compatible host. - Replace
PATHwith the path to the object on the S3-compatible host. - Replace
DURATIONwith the point-in-time in the past at which the command returns the object. For example, specify30dto 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
ALIASwith thealiasof the S3-compatible host. - Replace
PATHwith the path to the object on the S3-compatible host. - Replace
VERSIONwith 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.
Download a particular part
Use mc cat --part-number to download a particular part of a multi-part upload:
mc cat ALIAS/PATH --part-number=#
- Replace
ALIASwith thealiasof the S3-compatible host. - Replace
PATHwith the path to the object on the S3-compatible host. - Replace
#with the integer of the part number to download. For example, to download part 3 of at 16-part multi-part file, use--part-number=3.
You cannot use the --part-number flag if you are using either the --offset or the --tail flags.
Behavior
S3 Compatibility
The mc commandline tool is built for compatibility with the AWS S3 API and is tested with 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.
Portions of this page are adapted from the MinIO Object Storage Documentation, © 2020–Present MinIO, Inc., licensed under CC BY 4.0, converted and maintained by the Silo project. Attribution