Re: Binary or Ascii Text?

osmium writes：
The best you can do is make a guess. The first 32 characters of ASCII are
control codes and only a few of them (CR, LF, FF, HT (tab), .... are present
in text files. So if you have quite a few of the other 25 or so codes, it is
probably not a text file - but it's only an educated guess, no real proof.


Well, as matter of fact, I just got an idea to handle that problem. But
I don't know if it is feasible.

Now that we know ascii text only use 7 bits of a byte and the first bit
is always set as 0. So I wonder if I could write a program to get a
fixed length of a given file(for example, the first 1024 bytes) , to
store them in a unsigned char array and to check if there is any
elements greater than 0x7F. If any, the file can be judged as a binary
file.

However, the disadvantage of the above method is that it cannot handle
the multi-byte character. Take the UTF-8's japanese character for
example, a japanese character may be encoded as three bytes and some of
them may be greater than 0x7F。 In that case, my method will make no
sense.

.