Implements a heuristic algorithm, very much like the one used by Git, to
decide if some data is most likely to be text or binary.
# Test a Buf/Blob
say is-text('Vánoční stromek'.encode('utf-8')); # True
say is-text(Buf.new(0x02, 0xFF, 0x00, 0x38)); # False
# Test a file
say is-text('/bin/bash'.IO); # False
say is-text('/usr/share/dict/words'.IO); # True
The module exports a single subroutine
is-text, which has candidates for
IO::Path, enabling it to be used on data that has already been
read into memory as well as data in a file.
On a Blob
my $text = is-text($the-blob, test-bytes => 8192);
When called on a
is-text will test the first
test-bytes bytes of
it to decide if it contains text or binary data. The
parameter is optional, and its default value is 4096.
On an IO::Path
my $text = is-text($filename.IO, test-bytes => 8192);
When called on an
is-text will read the first
from the file it points to. It will then test these to decide if the file is
text or binary. The
test-bytes named parameter is optional, and its default
value is 4096.
The algorithm will flag a file as binary if it encounters a NULL byte or a
lone carriage return (
\r). Otherwise, it considers the ratio of printable
to ASCII-range control characters, with newline sequences excluded. If there
is less than one byte representing an unprintable ASCII character per 128
bytes representing printable ASCII characters, then the data is considered to
The function exported by this module is safe to call from multiple threads at
the same time.