nix store prefetch-file

nix store prefetch-file [option…] url

• Download a file to the Nix store:

# nix store prefetch-file https://releases.nixos.org/nix/nix-2.3.10/nix-2.3.10.tar.xz
Downloaded 'https://releases.nixos.org/nix/nix-2.3.10/nix-2.3.10.tar.xz' to
'/nix/store/vbdbi42hgnc4h7pyqzp6h2yf77kw93aw-source' (hash
'sha256-qKheVd5D0BervxMDbt+1hnTKE2aRWC8XCAwc0SeHt6s=').

• Download a file and get the SHA-512 hash:

# nix store prefetch-file --json --hash-type sha512 \
  https://releases.nixos.org/nix/nix-2.3.10/nix-2.3.10.tar.xz \
| jq -r .hash
sha512-6XJxfym0TNH9knxeH4ZOvns6wElFy3uahunl2hJgovACCMEMXSy42s69zWVyGJALXTI+86tpDJGlIcAySEKBbA==

This command downloads the file url to the Nix store. It prints out the resulting store path and the cryptographic hash of the contents of the file.

The name component of the store path defaults to the last component of url, but this can be overridden using --name.

• --executable
  Make the resulting file executable. Note that this causes the resulting hash to be a NAR hash rather than a flat file hash.
• --expected-hash hash
  The expected hash of the file.
• --hash-type hash-algo
  hash algorithm (‘md5’, ‘sha1’, ‘sha256’, or ‘sha512’)
• --json
  Produce output in JSON format, suitable for consumption by another program.
• --name name
  Override the name component of the resulting store path. It defaults to the base name of url.