vt-is-UTF8 - check whether current VT is in UTF8- or byte-mode.
vt-is-UTF8 checks whether the current VT is in UTF8
mode, by writing (and erasing afterwards) a 3-byte-long UTF8
sequence, and looking how much chars where displayed by the
A message telling in which mode the console is is then
written to stdout (except if the --quiet option was
If the --quiet option is not given, the value
returned is 1 if an error occurs, else 0.
display version number, a short help message and
display version number and exit.
do not print on stdout in with mode we are, but return the
state as exit-status 1 if in UTF8-mode, 0 if in byte-mode.
In case of error, 0 is returned and a message is displayed
The check should be done by directly asking the kernel,
which is not possible as of kernels 2.0.x.
As of kernel 2.0.35, the byte-mode is sometimes erroneously
detected as UTF8-mode, after switching from a 512-chars font
to a 256-chars font. This is probably a console-driver