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Getting HASH of individual files within folder uploaded to IPFS

When I upload a folder of .jpg files to IPFS, I get the HASH of that folder - which is cool.

But is each individual file in that folder also getting hashed? And if so, how do I get the hash of each file?

I basically want to be able to upload a whole bunch of files - like 500 images - and do it all at once, or programmatically, and have the hash of each file be returned to me.

Any way to do this?

Solution

  • Yes! From the command line you get back the CIDs (the Content IDentifier, aka, IPFS hash) for each file added when you run ipfs add -r <path to directory>

    $ ipfs add -r gifs
added QmfBAEYhJp9ZjGvv8utB3Yv8uuuxsDKjv9rurkHRsYU3ih gifs/martian-iron-man.gif
added QmRBHTH3p4W2xAzgLxvdh8VJvAmWBgchwCr9G98EprwetE gifs/needs-more-dogs.gif
added QmZbffnCcV598QxsUy7WphXCAMZJULZAzy94tuFZzbFcdK gifs/satisfied-with-your-care.gif
added QmTxnmk85ESr97j2xLNFeVZW2Kk9FquhdswofchF8iDGFg gifs/stone-of-triumph.gif
added QmcN71Qh56oSg2YXsEXuf8o6u5CrBXbyYYzgMyAkdkcxxK gifs/thanks-dog.gif
added QmTnuLaivKc1Aj8LBf2iWBHDXsmedip3zSPbQcGi6BFwTC gifs

    the root CID for the directory is always the last item in the list.

    You can limit the output of that command to just include the CIDs using the --quiet flag

    ⨎ ipfs add -r gifs --quiet
QmfBAEYhJp9ZjGvv8utB3Yv8uuuxsDKjv9rurkHRsYU3ih
QmRBHTH3p4W2xAzgLxvdh8VJvAmWBgchwCr9G98EprwetE
QmZbffnCcV598QxsUy7WphXCAMZJULZAzy94tuFZzbFcdK
QmTxnmk85ESr97j2xLNFeVZW2Kk9FquhdswofchF8iDGFg
QmcN71Qh56oSg2YXsEXuf8o6u5CrBXbyYYzgMyAkdkcxxK
QmTnuLaivKc1Aj8LBf2iWBHDXsmedip3zSPbQcGi6BFwTC

    Or, if you know the CID for a directory, you can list out the files it contains and their individual CIDs with ipfs ls. Here I list out the contents of the gifs dir from the previous example

    $ ipfs ls QmTnuLaivKc1Aj8LBf2iWBHDXsmedip3zSPbQcGi6BFwTC
QmfBAEYhJp9ZjGvv8utB3Yv8uuuxsDKjv9rurkHRsYU3ih 2252675 martian-iron-man.gif
QmRBHTH3p4W2xAzgLxvdh8VJvAmWBgchwCr9G98EprwetE 1233669 needs-more-dogs.gif
QmZbffnCcV598QxsUy7WphXCAMZJULZAzy94tuFZzbFcdK 1395067 satisfied-with-your-care.gif
QmTxnmk85ESr97j2xLNFeVZW2Kk9FquhdswofchF8iDGFg 1154617 stone-of-triumph.gif
QmcN71Qh56oSg2YXsEXuf8o6u5CrBXbyYYzgMyAkdkcxxK 2322454 thanks-dog.gif

    You can it programatically with the core api in js-ipfs or go-ipfs. Here is an example of adding a files from the local file system in node.js using js-ipfs from the docs for ipfs.addAll(files) - https://github.com/ipfs/js-ipfs/blob/master/docs/core-api/FILES.md#importing-files-from-the-file-system

    There is a super helpful video on how adding files to IPFS works over at https://www.youtube.com/watch?v=Z5zNPwMDYGg

    And a walk through of js-ipfs here https://github.com/ipfs/js-ipfs/tree/master/examples/ipfs-101