addfile#

Feed a filehandle or a file by name into a Digest::SHA object.

The public file-ingestion entry point. Accepts either an open filehandle or a filename string, plus an optional mode character that controls how bytes are read:

"b" (default): raw binary read. Use this for anything that is not human-readable text, or when you need bit-exact file digests.
"U": universal newlines. When the file looks like text (-T), CR/LF and lone CR line endings are read as LF, so a text file gives the same digest whatever its line endings; any other file is read as in "b".
"0": BITS mode. Interpret every '0' and '1' character in the file as a single bit and feed those bits into the hash. Anything else in the file is ignored.

Synopsis#

$sha->addfile("data.bin");                 # filename, binary
$sha->addfile($fh);                        # handle, binary
$sha->addfile("notes.txt", "U");           # universal newlines
$sha->addfile("bits.txt", "0");            # ASCII bit stream

What you get back#

The receiver, for chaining.

Examples#

my $sha = Digest::SHA->new(256);
$sha->addfile("archive.tar.gz");
print $sha->hexdigest;

# Cross-platform digest of a source file
my $sha = Digest::SHA->new(256);
$sha->addfile("src/main.c", "U");

# BITS mode: hash the bit pattern "01011010" repeated
my $sha = Digest::SHA->new(1);
$sha->addfile("bitstream.txt", "0");

my $sha = Digest::SHA->new(256);
open my $fh, "<:raw", "photo.jpg" or die $!;
$sha->addfile($fh);

Edge cases#

A missing or unreadable filename croaks with Open failed: ...; a read error, such as on a closed filehandle, croaks with Read failed: ....
The mode applies only to a filename; a filehandle is read as it is, whatever mode is given.
Unknown mode characters fall back to binary.
Empty files leave the hash state untouched.
Called on something that is not a Digest::SHA object, dies with Can't locate object method or Can't call method.

Differences from upstream#

Fully compatible with upstream Digest::SHA 6.04.