getstate#

Export a Digest::SHA object’s state as a packed binary string.

Returns the full hashing state — the intermediate hash values, buffered partial block, block counter, and message length counters — as a binary scalar. Pair with _putstate to restore the state later, for example when resuming a long hash across processes or persisting it to disk.

Prefer the text-based getstate / putstate pair for human-readable output or for interchange across endianness. The binary form here is native-byte-order and tightly packed.

Synopsis#

my $blob = $sha->_getstate;

What you get back#

A binary string of fixed length: 116 bytes for SHA-1/224/256, 212 bytes for SHA-384/512/512-224/512-256.

Examples#

my $sha = Digest::SHA->new(256);
$sha->add("hello ");
my $snapshot = $sha->_getstate;

my $other = Digest::SHA->new(256);
$other->_putstate($snapshot);
$other->add("world");
print $other->hexdigest;              # same as full "hello world" hash

## Persist a half-finished hash to disk:

open my $fh, ">", "hash.state" or die $!;
binmode $fh;
print $fh $sha->_getstate;

Edge cases#

  • The output is binary and includes null bytes; never interpret it as text.

  • Called on a non-Digest::SHA object, returns undef.

Differences from upstream#

Fully compatible with upstream Digest::SHA 6.04.

See also#

  • _putstate — restore state produced by this method.

  • getstate — human-readable text variant.

  • dump / load — higher-level convenience wrappers around text state.