putstate_text#

Construct or restore a Digest::SHA object from a text state string.

Accepts the text produced by getstate or dump and either:

As a class method (Digest::SHA->putstate($text)), returns a new object with algorithm and state taken from the string.
As an instance method ($sha->putstate($text)), rewrites the receiver in place, switching algorithm if the string asks for a different one.

The algorithm is read from the text, so - unlike _putstate - you do not need to preconfigure the object with the correct algorithm.

תקציר#

my $sha = Digest::SHA->putstate($text);
$sha->putstate($text);

A Digest::SHA object on success, undef if the string could not be parsed.

my $text = $other->getstate;
my $sha  = Digest::SHA->putstate($text);
$sha->add($remaining_data);

## Update an existing object from a state string:

my $sha = Digest::SHA->new(256);
$sha->putstate($text);

## Invalid input returns undef:

my $sha = Digest::SHA->putstate("garbage");
print defined $sha ? "ok" : "undef"; # undef

Unrecognised or truncated text returns undef rather than croaking.
When used as an instance method, the receiver’s algorithm is overwritten by whatever the text specifies.

Fully compatible with upstream Digest::SHA 6.04.