NAME
uterm - start script for a Unicode capable terminal window
SYNTAX
uterm [ -terminal-options ] [ -e program arguments ... ]
uterm [ -rx | -rxvt ] [ -rxvt-options ] [ -e program arguments ... ]
uterm [ -xt | -xterm ] [ -xterm-options ] [ -e program arguments ... ]
DESCRIPTION
Invoke a terminal window with a reasonably optimised range of Unicode
support, enforcing UTF-8 mode and using the best Unicode fonts found.
Many systems are not yet properly configured to enable easy and
straight-forward use of Unicode in a text-mode terminal environment
(such as xterm or rxvt). The purpose of uterm is to help users to
start a terminal with good Unicode capabilities without much hassle.
Terminal selection
Either of xterm or rxvt-unicode is selected as the terminal application
to start, depending on:
· Availability of rxvt-unicode: The script checks whether
rxvt-unicode is available under the name urxvt (e.g. on
cygwin), or if rxvt is available, whether it actually is
rxvt-unicode (and not an older version). Only if this
check is positive, rxvt is considered.
· User preference, implicit: If the environment variable
TERM starts with "rxvt", rxvt-unicode is preferred.
· User preference, explicit: With the command line option
--rx or -rxvt, rxvt-unicode is preferred. With -xt or
-xterm, xterm is preferred.
· Font selection: If the GNU unifont is selected, rxvt is
chosen.
· In all other cases, xterm is chosen.
Users of mlterm are assumed to start mlterm themselves directly, so
mlterm is not considered. Neither of KDE konsole or gnome-terminal is
currently considered since they cannot be font-configured on-the-fly.
Font selection
The uterm script tries its best to use fonts that provide a maximum of
Unicode support.
· First it checks if you have the 10x20 Unicode font and a
matching 20x20 double width font installed (see
explanation below about CJK coverage).
· If not, it checks if you have the 9x18 Unicode font and a
matching 18x18 double width font installed and uses them.
· If both are not found, it tries to invoke rxvt with the
GNU unifont.
· If either GNU unifont or rxvt are not installed, efont is
tried.
· As a last resort, it tries to invoke xterm with 6x13 and
12x13 fonts.
· As a very last fallback, it invokes xterm with its
configured default fonts.
Note: The efonts are installed on fewer systems than the misc-fixed
fonts so only 1 size of them is considered and at a lower priority. If
you prefer efont, you should configure xterm font usage yourself (using
X resource configuration) and invoke xterm directly.
Note: GNU unifont does unfortunately not work with xterm (or rather
xterm with GNU unifont), so in this case rxvt is invoked.
Information about font usage
Font selection is a matter of both taste and script coverage. The
uterm script uses fonts with a good coverage of Unicode script ranges,
but its order of precedence may not suit your specific needs. In that
case you should configure your exact desired font preference and invoke
the desired terminal (xterm, rxvt) directly. Coverage of certain
scripts would suggest certain font preferences: Korean Hangul: GNU
unifont Devanagari: efont Georgian: efont, misc X fonts
...
CJK coverage and the 10x20 fonts
Among the Unicode "misc" X fonts (misc-fixed-...), the 20 pixel size
fonts are much clearer in appearance than the 18 pixel fonts for which
CJK wide fonts (using double cell width in a fixed-width terminal) are
available. Unfortunately, xterm is not yet capable of padding an 18x18
font up to 20x20 pixel character cells for use together with a 10x20
pixel font. The bdf18to20 script, packaged with the mined editor like
uterm, helps with this issue and generates the missing fonts from the
18 pixel double width fonts by padding blank pixels. If you have
installed those, uterm will select 20 pixel fonts as its first
preference.
Note: 20x20 fonts (padded with bdf18to20) are already installed as part
of the xterm package with SuSE Linux 10.0.
Note: The 6x13 pixel font from Unicode misc-fixed-... also has a
matching 12x13 CJK font but that size is really much too small for
serious application on modern desktops which often provide higher
resolutions than traditional workstations.
UTF-8 environment setup
The uterm script enforces UTF-8 mode with the terminal and also sets up
the locale variable environment to reflect UTF-8 terminal encoding. If
necessary, all LC_* and LANG environment variables are modified to
provide a proper environment for applications started inside the
Unicode terminal. (See the inline documentation of the uterm script for
how this is done.)
X resource class
When starting xterm, uterm uses the X resource class UXTerm so you can
configure the desired appearance of UTF-8 mode terminal windows in your
X resource configuration. For rxvt-unicode, the class URxvt can be
used for X resources.
Unicode width data version
If called with an -e option to invoke a specific program in it, uterm
enables the -mk_width option of xterm (if xterm version 201 or newer is
available). This tells xterm to use its own, compiled-in character
width property tables, rather than using system locale information.
The advantage is that this information is often newer (referring to a
newer version of Unicode) than the installed system data. Thus the
user is enabled to use up-to-date Unicode data by using a
self-installed copy of xterm, rather than being stuck with the Unicode
data that the system administrator cares to install. This is
especially useful if the application is known to be able to recognise
that Unicode version, like the Unicode editor mined. The umined script
makes use of this feature to invoke mined in a Unicode terminal with a
maximum of Unicode support.
Keyboard resources for application use
If called with an -e option to invoke a specific program in it, uterm
also enables a number of other xterm resources in order to enable best
keyboard and terminal control for applications:
*VT100*eightBitOutput:true
to enable 8 Bit output (actually not needed in UTF-8 mode)
*VT100*metaSendsEscape:true
to enable ESC prefixing triggered by Alt-key
*VT100*eightBitInput:false
to enable ESC prefixing triggered by Alt-key in old xterm
versions
*VT100*deleteIsDEL:true
to enable distinguishing the two DEL keys on the keyboard
*utf8Title:true
to enable UTF-8 window title strings
FILES
$HOME/.Xdefaults or $HOME/.Xresources
typical location of user’s X resource configuration
AUTHOR
The uterm script is an auxiliary script packaged with the mined editor
by Thomas Wolff. Please send comments, suggestions, bug reports to
mined@towo.net.