Mutable File System | Lesson 9 of 11

Copy a file or directory

Unlike, which removes items from their source path when moving them to their destination path, the files.cp method allows you to a copy a file or directory to a new location while also leaving it intact at its source.

The method looks like this:

await ipfs.files.cp(...from, to, [options])

However, you now have two formatting options for from. You can pass in either:

  • an existing MFS path to a file or a directory in your own node (e.g. /my-dir/my-file.txt)
  • an IPFS path to a file or directory hosted either by you or by a peer (e.g. /ipfs/QmWGeRAEgtsHW3ec7U4qW2CyVy7eA2mFRVbk1nb24jFyks)

Notice that an IPFS path starts with /ipfs/ and ends with a CID.

As you saw with, to is the destination path in MFS, and there's an option { parents: true } that can be used to create parent directories that don't already exist.

You can use files.cp to perform a number of different operations:

// copy a single file into a directory
await ipfs.files.cp('/source-file.txt', '/destination-directory')
await ipfs.files.cp('/ipfs/QmWGeRAEgtsHW3ec7U4qW2CyVy7eA2mFRVbk1nb24jFyks', '/destination-directory')

// copy multiple files into a directory (note the two acceptable formats with or without [ ])
await ipfs.files.cp('/source-file-1.txt', '/source-file-2.txt', '/destination-directory')
await ipfs.files.cp(['/source-file-1.txt', '/source-file-2.txt'], '/destination-directory')
await ipfs.files.cp('/ipfs/QmWGeRAEgtsHW3ec7U4qW2CyVy7eA2mFRVbk1nb24jFyks',
 '/ipfs/QmWGeRAEgtsHW3jk7U4qW2CyVy7eA2mFRVbk1nb24jFyre', '/destination-directory')
await ipfs.files.cp(['/ipfs/QmWGeRAEgtsHW3ec7U4qW2CyVy7eA2mFRVbk1nb24jFyks',
 '/ipfs/QmWGeRAEgtsHW3jk7U4qW2CyVy7eA2mFRVbk1nb24jFyre'], '/destination-directory')

// copy a directory into another directory
await ipfs.files.cp('/source-directory', '/destination-directory')
await ipfs.files.cp('/ipfs/QmWGeRAEgtsHW3ec7U4qW2CyVy7eA2mFRVbk1nb24jFyks', '/destination-directory')

Gotcha! If you copy a file from an IPFS path without explicitly assigning it a filename, IPFS will set its name property equal to its CID. To specify a more friendly filename, you'll need to append it to the destination path like so:

await ipfs.files.cp('/ipfs/QmWGeRAEgtsHW3ec7U4qW2CyVy7eA2mFRVbk1nb24jFyks', '/destination-directory/fab-file.txt')

Try it!

We've created a text file containing a secret message and stored it on the IPFS network under CID QmWCscor6qWPdx53zEQmZvQvuWQYxx1ARRCXwYVE4s9wzJ. Copy it from the IPFS network into your /some/stuff directory in MFS and give it the name success.txt by appending the desired filename to the destination path.

Hint: An IPFS path starts with /ipfs/ and ends with a CID.

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