nix3-store-prefetch-file(1) General Commands Manual nix3-store-prefetch-file(1)

Warning
This program is experimental and its interface is subject to change.

nix store prefetch-file - download a file into the Nix store

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.
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--expected-hash hash
The expected hash of the file.
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--hash-type hash-algo
Hash algorithm (md5, sha1, sha256, or sha512).
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--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.
•
--unpack
Unpack the archive (which must be a tarball or zip file) and add the result to the Nix store.
•
--debug
Set the logging verbosity level to ‘debug’.
•
--log-format format
Set the format of log output; one of raw, internal-json, bar or bar-with-logs.
•
--print-build-logs / -L
Print full build logs on standard error.
•
--quiet
Decrease the logging verbosity level.
•
--verbose / -v
Increase the logging verbosity level.

•
--help
Show usage information.
•
--offline
Disable substituters and consider all previously downloaded files up-to-date.
•
--option name value
Set the Nix configuration setting name to value (overriding nix.conf).
•
--refresh
Consider all previously downloaded files out-of-date.
•
--version
Show version information.

Note

See man nix.conf for overriding configuration settings with command line flags.