xvt
NAME
xvt - VT100 emulator for the X window system
SYNOPSIS
xvt [ options ]
DESCRIPTION
Xvt is a VT100 terminal emulator for X. It is intended as a
replacement for xterm(1) for users who do not require the
more esoteric features of xterm. Specifically xvt does not
implement the Tektronix 4014 emulation, session logging and
toolkit style configurability. As a result, xvt uses much
less swap space than xterm - a significant advantage on a
machine serving many X sessions.
OPTIONS
The options supported by xvt (which, with the exception of
-msg, are a subset of those supported by xterm) are listed
below. Most command line arguments have X resource
equivalents and these are listed in the following table.
-e command [ arguments ]
Run the command with its command line arguments in the
xvt window. If this option is used, it must be the
last on the command line. If there is no -e option
then the default is to run the program specified by the
SHELL environment variable or, failing that, csh(1).
This option also causes the window title and icon name
to be set to the name of the program being executed if
the are not overwritten by a more specific option.
-display display-name
Attempt to open the xvt window on the named X display.
In the absence if this option, the display specified by
the DISPLAY environment variable is used.
-geometry window-geometry
Create the window with the specified X window geometry.
-background color
Use the specified color as the window's background
color.
-bg color
Same as -background.
-foreground color
Use the specified colour as the window's foreground
color.
-fg color
Same as -foreground.
-bw number
Set the window border width to number pixels. many
window managers ignore existing window borders and
construct their own and so, if you are using such a
window manager, this option will be ignored.
-bd color
Set the border color. As with border width, this
option will usually be disregarded with respect to the
window's outer border. It does, however, set the color
of the line separating the scroll bar from the main
part of the window.
-font fontname
Set the main text font used by xvt.
-fb fontname
Set the font used for the vt100 bold rendition style.
Unlike xterm, the current version of xvt will not try
and create bold text by displacing and or'ing an
ordinary font and so, if you want bold highlighting to
work, you need to use this option to specify a suitable
bold font.
-name name
Set the name that is used when looking up X resource
values for this instance of xvt. This option also sets
the icon name and window title unless they are set
explicitely.
-title text
Set the string that is displayed in the window's title
bar if it has one.
-T text
Same as -title
-n text
Set the name that will be used to label the window's
icon or displayed in an icon manager window. This
option also sets the window's title unless it is set
expicitely.
-sl number
Set an upper bound for the number of lines that will be
saved when they have scrolled off the top of the
window.
-sb Start up with the scrollbar visible. The scrollbar can
be displayed or hidden at any time simply by holding
down the CONTROL key on the keyboard and pressing any
mouse button. The visibility of the scrollbar does not
determine whether scrolled text is saved or not - as
with xterm, text scrolled off the top of the window is
always saved up to the current maximum number of lines.
-rw Enable reverse wrapping of the cursor so that, for
example, lines typed to a shell that are longer than
the width of the screen can be edited. This is the
same as the xterm reverse wrap option.
-cc string
Input or modify the character classes that are used to
determine what is a word when a double click is used to
select a word of displayed text. This is identical to
the same option in xterm - see the xterm manual page
for a description of the syntax of string.
-iconic
Start up with the window already iconized.
-msg Enable messages to the terminal window from programs
like write(1). By default, xvt windows have messages
disabled. Executing an xvt with the -msg option has
the same effect as running it normally and then
executing the command mesg y to enable messages.
X RESOURCES
With the necessary exception of -e, -display and -name, all
the command line options have X resource counterparts and
these are listed in the following table. Like xterm, xvt
uses the class name XTerm and so resource options set for
XTerm will work for both xterm and xvt windows.
center tab(/) ; cb s s c c s c c c l l l . Command line
options and X resources _ /X resource Command
line/Instance/Class = -e/-/- -display/-/- -name/-/-
-geometry/geometry/Geometry -background or
-bg/background/Background -foreground or
-fg/foreground/Foreground -bw/borderWidth/BorderWidth
-bd/borderColor/BorderColor -font/font/Font
-fb/boldFont/BoldFont -title or -T/title/Title
-n/iconName/IconName -sl/saveLines/SaveLines
-sb/scrollBar/ScrollBar -rw/reverseWrap/ReverseWrap
-cc/charClass/CharClass -iconic/iconic/Iconic
-msg/messages/Messages
TITLES NAMES AND ICON NAMES
One occasionally confusing aspect of xvt and other X
applications is the collection of names that an application
window can have and the relationship between the names and
the command line options used to set them. This section
attempts to make the situation a bit clearer in the case of
xvt.
In fact, each terminal window has three names, its resource
name, its title and its icon name. These three names are
distinct and have different functions, although they usually
have the same value. The resource name is the command name
used to identify X resource options in the resources
database, The title is the text that is displayed in the
title bar, if there is one, and the icon name is the name
that appears in the window's icon or represents it in the
icon manager window.
The rule about which option sets which name is that -name
and -e set both the title and the icon name in addition to
their main function and -n sets the title as well as the
icon name. Conflicts are resolved by giving the options
priorities which are, in increasing order, -e, -name, -n and
-title. Hence, for example, -e only sets the title if none
of the other options is used.
THE SCROLL BAR
Lines of text that scroll off the top of the xvt window are
saved automatically (up to a preset maximum number) and can
be viewed by scrolling them back into the window with the
scrollbar. The scrollbar itself can be displayed or hidden
by clicking any mouse button in the window while holding
down the CONTROL key on the keyboard. When using the
scrollbar, the left and right mouse buttons are used for
scrolling by a few lines at a time and the middle button is
used for continuous scrolling. To use the middle button,
press it in the scroll bar and hold it down. the central
shaded part of the scrollbar will then attach itself to the
cursor and can be slid up or down to show different parts of
the sequence of saved lines. When scrolling with the left
and right buttons, the left button is used to scroll up and
the right is used to scroll down. Assuming that there are
enough hidden lines, the distance scrolled with either
button is equal to the number of lines between the cursor
and the top of the window. Hence, pressing the left cursor
opposite a line of text will result in that line being moved
to be the top of the window and pressing the right button
will cause the top line to be moved down so that it is
opposite the cursor.
TEXT SELECTION AND INSERTION
Xvt uses the same kind of text selection and insertion
mechanism as xterm. Pressing and releasing the middle mouse
button in an xvt window causes the current text selection to
be inserted as if it had been typed on the keyboard. For
the insertion to take place, both the button press and the
button release need to be done with the cursor in the xvt
window.
The left and right mouse buttons are used to select text,
with the left button being used to start a selection and the
right button being used to modify an existing selection.
Any continuous block of displayed text can be selected. If
both ends of the text block are visible in the window then
the easiest way to select it is to position the cursor at
one end and press the left mouse button, then drag the
cursor to the other end with the button held down before
releasing the button. If the block is larger than the
window then you must first use the left mouse button to
select one end, then use the scroll bar to scroll the other
end into view and finally use the right mouse button to
extend the selection. The effect of pressing the right
mouse button is to move the nearest end of the current
selection to the current cursor position.
The other way to make selections in xvt is to use double and
triple clicks of the left mouse button with a double click
selecting a word and a triple click selecting a whole line.
For this purpose, a word is a sequence of characters in the
same class. The default character classes are:
+ the upper and lower case letters, digits and '_'
(underscore) all in one class;
+ the white space characters all in one class;
+ each of the remaining punctuation characters in a class
by itself.
If you want to change the character classes so that, for
example, you can select a UNIX pathname or a mail address in
one double click, then you can do so by using the -cc
command line option or the charClass X resource. Multiple
clicking can be combined with dragging to select a sequence
of consecutive words or lines.
Although xvt essentially mimics the behaviour of xterm in
its support of text selection and insertion, there are a
couple of minor differences:
+ xvt respects TAB characters in selected text and does not
automatically convert them into spaces as does xterm;
+ xvt will let you abort a text insertion if you realise
you have made a mistake before releasing the middle mouse
button.
BUGS
Pasting very large quantities of text does not work.
AUTHOR
John Bovey, University of Kent, 1992.