Rodrigo Barbosa wrote: > -----BEGIN PGP SIGNED MESSAGE----- > Hash: SHA1 > > On Sun, Sep 03, 2006 at 08:11:18AM +0800, John Summerfield wrote: > >>The correct behaviour for the backspace key is to send the BS character, >>0x08 aka ^H. >> >>^? I suspect is the DEL character, 0x7f, which is unprintable (or prints >>as a space). I would expect the Delete key to produce a DEL character. > > > The correct behaviour for who ? For many platforms (Sun is the first > one that comes to memory), the correct backspace char was always > ^? By definition of the American National Standards Institute. > > At least here, for me, DEL shows are ^[[3~ (ANSI code ?!?). Those are character interpretations, not the underlying codes. They are ANSI control sequences for controlling terminals. I suspect they originated with the Digital Equipment Corporation, possibly with its VT100 glass teletypes. The backspace character's original purpose was to tell a printer-keyboard to back space one position, so the next chracter would overtype the previous: it was exactly opposite to a space. The DEL character is also known as RUBOUT. Why? In the olden days, we used paper tape. Nobody wanted to throw out, or rekey, a roll of paper tape because of a small error. How do we fix a wrong character/ We rub it out. We punch holes across the tape, and so the value 0x7f (remember, ASCII is a seven-bit code). A program reading data from paper tape had to recongise special control characters; one of them was DEL, which it simply dropped. > > Yes, on ASCII, DEL is 7F and BS is 08. But remember the issue here are > not charsets, but console control codes, which usually are the same, but > not always. > > The definition is kind of iffy, but on the console_codes manpage > it states that, for Linux BS should indeed produce ^H. But lets remember > that is Linux specific, and might not be true to many other platforms. -- Cheers John -- spambait 1aaaaaaa at coco.merseine.nu Z1aaaaaaa at coco.merseine.nu Tourist pics http://portgeographe.environmentaldisasters.cds.merseine.nu/ Please do not reply off-list