<!-- GENERATED by docs/sphinx/bin/02-reference from Digest/SHA.rs (xs_dump). Do not edit. -->

```{index} single: dump; Digest::SHA function
```
```{index} single: Digest::SHA::dump; Perl function
```

# dump

Write the current `Digest::SHA` state to a file or STDOUT in text form.

With a filename argument, writes the text produced by `getstate` to
that file, truncating it if it exists. Without an argument, prints the
same text to STDOUT. The companion `load` method reads it back.

## Synopsis

```perl
$sha->dump("hash.state");
$sha->dump;                   # to STDOUT
```

## What you get back

`1` on success (truthy), `undef` on I/O failure.

## Examples

```perl
my $sha = Digest::SHA->new(256);
$sha->add("partial");
$sha->dump("checkpoint.state");

## ... later, perhaps in another process ...

my $resumed = Digest::SHA->load("checkpoint.state");
$resumed->add("tail");
print $resumed->hexdigest;
```

```perl

## Debug-dump to the terminal:

$sha->dump;
```

```perl

## Check the return value for I/O errors:

defined $sha->dump("/nonexistent/path/file")
    or warn "could not write state";
```

## Edge cases

- An unwritable path returns `undef` rather than croaking.
- Called on a non-`Digest::SHA` object, returns `undef`.

## Differences from upstream

Fully compatible with upstream `Digest::SHA` {{ upstream.Digest_SHA }}.

## See also

- `load` — counterpart that reads the file `dump` produces.
- `getstate` — underlying text-state producer.
- `putstate` — text-state ingester.