the hash of the [Nix Archive (NAR)](@docroot@/store/file-system-object/content-address.md#serial-nix-archive) of *path*,
  just [directly hash]((@docroot@/store/file-system-object/content-address.md#serial-flat) *path* as is.
  This requires *path* to resolve to a regular file rather than directory.
  The result is identical to that produced by the GNU commands
  `md5sum` and `sha1sum`.

- `--base16`

  Print the hash in a hexadecimal representation (default).

- `--base32`

  Print the hash in a base-32 representation rather than hexadecimal.
  This base-32 representation is more compact and can be used in Nix
  expressions (such as in calls to `fetchurl`).

- `--base64`

  Similar to --base32, but print the hash in a base-64 representation,
  which is more compact than the base-32 one.

- `--sri`

  Print the hash in SRI format with base-64 encoding.
  The type of hash algorithm will be prepended to the hash string,
  followed by a hyphen (-) and the base-64 hash body.

- `--truncate`

  Truncate hashes longer than 160 bits (such as SHA-256) to 160 bits.

- `--type` *hashAlgo*

  Use the specified cryptographic hash algorithm, which can be one of
  `blake3`, `md5`, `sha1`, `sha256`, and `sha512`.

- `--to-base16`

  Don’t hash anything, but convert the base-32 hash representation
  *hash* to hexadecimal.

- `--to-base32`

  Don’t hash anything, but convert the hexadecimal hash representation
  *hash* to base-32.

- `--to-base64`

  Don’t hash anything, but convert the hexadecimal hash representation
  *hash* to base-64.

- `--to-sri`

  Don’t hash anything, but convert the hexadecimal hash representation
  *hash* to SRI.

# Examples

Computing the same hash as `nix-prefetch-url`:

```console
$ nix-prefetch-url file://<(echo test)
1lkgqb6fclns49861dwk9rzb6xnfkxbpws74mxnx01z9qyv1pjpj
$ nix-hash --type sha256 --flat --base32 <(echo test)
1lkgqb6fclns49861dwk9rzb6xnfkxbpws74mxnx01z9qyv1pjpj
```

Computing hashes:

```console
$ mkdir test
$ echo "hello" > test/world

$ nix-hash test/ (MD5 hash; default)
8179d3caeff1869b5ba1744e5a245c04

$ nix-store --dump test/ | md5sum (for comparison)
8179d3caeff1869b5ba1744e5a245c04  -

$ nix-hash --type sha1 test/
e4fd8ba5f7bbeaea5ace89fe10255536cd60dab6

$ nix-hash --type sha1 --base16 test/
e4fd8ba5f7bbeaea5ace89fe10255536cd60dab6

$ nix-hash --type sha1 --base32 test/
nvd61k9nalji1zl9rrdfmsmvyyjqpzg4

$ nix-hash --type sha1 --base64 test/
5P2Lpfe76upazon+ECVVNs1g2rY=

$ nix-hash --type sha1 --sri test/
sha1-5P2Lpfe76upazon+ECVVNs1g2rY=

$ nix-hash --type sha256 --flat test/
error: reading file `test/': Is a directory

$ nix-hash --type sha256 --flat test/world
5891b5b522d5df086d0ff0b110fbd9d21bb4fc7163af34d08286a2e846f6be03
```

Converting between hexadecimal, base-32, base-64, and SRI:

```console
$ nix-hash --type sha1 --to-base32 e4fd8ba5f7bbeaea5ace89fe10255536cd60dab6
nvd61k9nalji1zl9rrdfmsmvyyjqpzg4

$ nix-hash --type sha1 --to-base16 nvd61k9nalji1zl9rrdfmsmvyyjqpzg4
e4fd8ba5f7bbeaea5ace89fe10255536cd60dab6

$ nix-hash --type sha1 --to-base64 e4fd8ba5f7bbeaea5ace89fe10255536cd60dab6
5P2Lpfe76upazon+ECVVNs1g2rY=

$ nix-hash --type sha1 --to-sri nvd61k9nalji1zl9rrdfmsmvyyjqpzg4
sha1-5P2Lpfe76upazon+ECVVNs1g2rY=

$ nix-hash --to-base16 sha1-5P2Lpfe76upazon+ECVVNs1g2rY=
e4fd8ba5f7bbeaea5ace89fe10255536cd60dab6
```