How many chars read -r line can read from tty?

[Peng Yu]

Hi,

read -r line; echo ${#line}

The above code does not work when the input is long. I tried to paste
to the terminal a string of 1024 characters. When I type return, I
just hear beeping. read won't finish so that the length of $line can
be printed.

If I try a string with length 1023, it will finish correctly and print 1023.

Anybody know why there is such a limit?

-- 
Regards,
Peng