I’ve searched the Ruby documentation, and I can’t find descriptions of
anything that corresponds to Perl’s -T' and-B’ tests … these test
whether a file contains ASCII text or “binary” data, respectively.
I’m happy to write such a test myself in Ruby and then post it here, and
I can easily do so. But I prefer not to re-invent the wheel, so does
anyone know of such a thing that already might have been written, or
which I might have missed in my search through the docs?
Thank you very much in advance.
···
–
Lloyd Zusman
ljz@asfast.com
ts decoux@moulon.inra.fr writes:
I’ve searched the Ruby documentation, and I can’t find descriptions of
anything that corresponds to Perl’s -T' and -B’ tests … these test
whether a file contains ASCII text or “binary” data, respectively.
See [ruby-talk:44936]
Thank you very much.
Yes, the code in this post this is a version of the text/binary test
that currently exists in Perl, and it’s pretty much what I would have
written … although I’d probably change the “non-ASCII” test. As coded
in the example you referred me to, certain normal ASCII text characters
(such as TAB, to name but one) would incorrectly cause a file to be
flagged as binary.
I also would want this test to be performable on a file that’s already
open (i.e., an IO object).
I’ll wait a day or so to see if someone reports any other currently
written code, but if not, I’ll write and post my own version here.
Guy Decoux
Thank you again.
···
–
Lloyd Zusman
ljz@asfast.com
Lloyd Zusman ljz@asfast.com writes:
ts decoux@moulon.inra.fr writes:
I’ve searched the Ruby documentation, and I can’t find descriptions of
anything that corresponds to Perl’s -T' and -B’ tests … these test
whether a file contains ASCII text or “binary” data, respectively.
See [ruby-talk:44936]
[ … ]
I’ll wait a day or so to see if someone reports any other currently
written code, but if not, I’ll write and post my own version here.
I’ve written an extension to File::Stat which adds a textfile? and
binaryfile? method. Each works pretty much the same as the file?
and directory? methods of File::Stat. For example:
s0 = File.stat(“/etc/fstab”)
s1 = File.stat(“/bin/sh”)
s2 = File.stat(“/tmp”)
p s0.textfile? => true
p s0.binaryfile? => false
p s1.textfile? => false
p s1.binaryfile? => true
p s2.textfile? => false
p s2.binaryfile? => false
It currently only works with File#stat, but eventually, I’d like to make
this work with IO#stat and File#lstat.
But before I do this work, I’d like the group’s feedback on what I’ve
written so far. Thanks in advance.
class File
def self.stat(arg)
Stat.new(arg)
end
class Stat
private
def self.isText(block)
return (block.count("^ -~", "^\b\f\t\r\n") < (block.size / 3.0) &&
block.count("\x00") < 1)
end
public
alias_method :__old_initialize, :initialize
def initialize(arg)
@item = arg
__old_initialize(arg)
end
# The textfile? and binaryfile? methods are not inverses of each
# other. Both return false if the item is not a file, or if the
# item is a zero-length file. The "textness" or "binariness" of
# an item can only be determined if it's a file that contains at
# least one byte.
def textfile?
if self.zero? then
return false
end
begin
open(@item) {
>file>
block = file.read(self.blksize < self.size ?
self.blksize : self.size)
return self.class.isText(block)
}
rescue
return false
end
end
def binaryfile?
if self.zero? then
return false
end
begin
open(@item) {
>file>
block = file.read(self.blksize < self.size ?
self.blksize : self.size)
return !self.class.isText(block)
}
rescue
return false
end
end
end # class Stat
end # class File
···
–
Lloyd Zusman
ljz@asfast.com
Hi,
I’ve written an extension to File::Stat which adds a textfile? and
binaryfile? method. Each works pretty much the same as the file?
and directory? methods of File::Stat. For example:
Why not File::textfile? and so on?
def initialize(arg)
@item = arg
super
···
At Sun, 11 Aug 2002 11:41:00 +0900, Lloyd Zusman wrote:
end
–
Nobu Nakada
nobu.nokada@softhome.net writes:
Hi,
I’ve written an extension to File::Stat which adds a textfile? and
binaryfile? method. Each works pretty much the same as the file?
and directory? methods of File::Stat. For example:
Why not File::textfile? and so on?
Hello, and thank you for your feedback.
Well, to me, the textfile? and binaryfile? methods seem closer in
meaning to the file?, directory?, etc. methods of File::Stat. And if
I’m not mistaken, the necessity to inspect the data inside of a file in
order to determine whether it’s a text file or binary file is
OS-specific … I believe that there are some OS’s where this is just an
attribute of a file that can be determined by making some sort of system
call, in a similar way to which the inode, device, etc. are returned via
the Unix stat() system call.
So to me, textfile? and binaryfile? seem “stat-like”, rather than
“file-like” methods.
But I don’t have a strong objection to making this a method of File …
to me, this is just a matter of personal taste, and I am flexible.
def initialize(arg)
@item = arg
super
end
??? “super” doesn’t work in place of __old_initialize(arg) in my code.
Neither does “super(arg)”. What would the superclass be in this case?
···
At Sun, 11 Aug 2002 11:41:00 +0900, > Lloyd Zusman wrote:
Nobu Nakada
–
Lloyd Zusman
ljz@asfast.com
Hi,
Well, to me, the textfile? and binaryfile? methods seem closer in
meaning to the file?, directory?, etc. methods of File::Stat. And if
I’m not mistaken, the necessity to inspect the data inside of a file in
order to determine whether it’s a text file or binary file is
OS-specific … I believe that there are some OS’s where this is just an
attribute of a file that can be determined by making some sort of system
call, in a similar way to which the inode, device, etc. are returned via
the Unix stat() system call.
It’s true certainly in particular system but not in many
others. I don’t guess it’s common and feel Stat is too
restrictive to bind text/binary-ness.
def initialize(arg)
@item = arg
super
end
??? “super” doesn’t work in place of __old_initialize(arg) in my code.
Neither does “super(arg)”. What would the superclass be in this case?
Oops, it wasn’t a subclass but Stat itself, sorry.
···
At Sun, 11 Aug 2002 12:42:50 +0900, Lloyd Zusman wrote:
–
Nobu Nakada