4.3BSD-UWisc/man/cat1/window.1
WINDOW(1) UNIX Programmer's Manual WINDOW(1)
NAME
window - window environment
SYNOPSIS
window [ -t ] [ -f ] [ -d ] [ -e escape-char ] [ -c command
]
DESCRIPTION
_W_i_n_d_o_w implements a window environment on ASCII terminals.
A window is a rectangular portion of the physical terminal
screen associated with a set of processes. Its size and
position can be changed by the user at any time. Processes
communicate with their window in the same way they normally
interact with a terminal--through their standard input, out-
put, and diagnostic file descriptors. The window program
handles the details of redirecting input an output to and
from the windows. At any one time, only one window can
receive input from the keyboard, but all windows can simul-
taneously send output to the display.
Windows can overlap and are framed as necessary. Each win-
dow is named by one of the digits ``1'' to ``9''. This one
character identifier, as well as a user definable label
string, are displayed with the window on the top edge of its
frame. A window can be designated to be in the _f_o_r_e_g_r_o_u_n_d,
in which case it will always be on top of all normal, non-
foreground windows, and can be covered only by other fore-
ground windows. A window need not be completely within the
edges of the terminal screen. Thus a large window (possibly
larger than the screen) may be positioned to show only a
portion of its full size.
Each window has a cursor and a set of control functions.
Most intelligent terminal operations such as line and char-
acter deletion and insertion are supported. Display modes
such as underlining and reverse video are available if they
are supported by the terminal. In addition, similar to ter-
minals with multiple pages of memory, each window has a text
buffer which can have more lines than the window itself.
OPTIONS
When _w_i_n_d_o_w starts up, the commands (see long commands
below) contained in the file ._w_i_n_d_o_w_r_c in the user's home
directory are executed. If it does not exist, two equal
sized windows spanning the terminal screen are created by
default.
The command line options are
-t Turn on terse mode (see _t_e_r_s_e command below).
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-f Fast. Don't perform any startup action.
-d Ignore ._w_i_n_d_o_w_r_c and create the two default windows
instead.
-e escape-char
Set the escape character to _e_s_c_a_p_e-_c_h_a_r. _E_s_c_a_p_e-_c_h_a_r
can be a single character, or in the form ^_X where _X is
any character, meaning control-_X.
-c command
Execute the string _c_o_m_m_a_n_d as a long command (see
below) before doing anything else.
PROCESS ENVIRONMENT
With each newly created window, a shell program is spawned
with its process environment tailored to that window. Its
standard input, output, and diagnostic file descriptors are
bound to one end of either a pseudo-terminal (_p_t_y (4)) or a
UNIX domain socket (_s_o_c_k_e_t_p_a_i_r (4)). If a pseudo-terminal
is used, then its special characters and modes (see _s_t_t_y
(1)) are copied from the physical terminal. A _t_e_r_m_c_a_p (5)
entry tailored to this window is created and passed as
environment (_e_n_v_i_r_o_n (5)) variable _T_E_R_M_C_A_P. The termcap
entry contains the window's size and characteristics as well
as information from the physical terminal, such as the
existence of underline, reverse video, and other display
modes, and the codes produced by the terminal's function
keys, if any. In addition, the window size attributes of
the pseudo-terminal are set to reflect the size of this win-
dow, and updated whenever it is changed by the user. In
particular, the editor _v_i (1) uses this information to
redraw its display.
OPERATION
During normal execution, _w_i_n_d_o_w can be in one of two states:
conversation mode and command mode. In conversation mode,
the terminal's real cursor is placed at the cursor position
of a particular window--called the current window--and input
from the keyboard is sent to the process in that window.
The current window is always on top of all other windows,
except those in foreground. In addition, it is set apart by
highlighting its identifier and label in reverse video.
Typing _w_i_n_d_o_w's escape character (normally ^P) in conversa-
tion mode switches it into command mode. In command mode,
the top line of the terminal screen becomes the command
prompt window, and _w_i_n_d_o_w interprets input from the keyboard
as commands to manipulate windows.
There are two types of commands: short commands are usually
one or two key strokes; long commands are strings either
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typed by the user in the command window (see the ``:'' com-
mand below), or read from a file (see _s_o_u_r_c_e below).
SHORT COMMANDS
Below, # represents one of the digits ``1'' to ``9''
corresponding to the windows 1 to 9. ^_X means control-_X,
where _X is any character. In particular, ^^ is control-^.
_E_s_c_a_p_e is the escape key, or ^[.
# Select window # as the current window and return to
conversation mode.
%# Select window # but stay in command mode.
^^ Select the previous window and return to conversation
mode. This is useful for toggling between two windows.
escape
Return to conversation mode.
^P Return to conversation mode and write ^P to the current
window. Thus, typing two ^P's in conversation mode
sends one to the current window. If the _w_i_n_d_o_w escape
is changed to some other character, that character
takes the place of ^P here.
? List a short summary of commands.
^L Redraw the screen.
q Exit _w_i_n_d_o_w. Confirmation is requested.
^Z Suspend _w_i_n_d_o_w.
w Create a new window. The user is prompted for the
positions of the upper left and lower right corners of
the window. The cursor is placed on the screen and the
keys ``h'', ``j'', ``k'', and ``l'' move the cursor
left, down, up, and right, respectively. The keys
``H'', ``J'', ``K'', and ``L'' move the cursor to the
respective limits of the screen. Typing a number
before the movement keys repeats the movement that
number of times. Return enters the cursor position as
the upper left corner of the window. The lower right
corner is entered in the same manner. During this pro-
cess, the placement of the new window is indicated by a
rectangular box drawn on the screen, corresponding to
where the new window will be framed. Typing escape at
any point cancels this command.
This window becomes the current window, and is given
the first available ID. The default buffer size is
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used (see _n_l_i_n_e command below).
Only fully visible windows can be created this way.
c# Close window #. The process in the window is sent the
hangup signal (see _k_i_l_l (1)). _C_s_h (1) should handle
this signal correctly and cause no problems.
m# Move window # to another location. A box in the shape
of the window is drawn on the screen to indicate the
new position of the window, and the same keys as those
for the _w command are used to position the box. The
window can be moved partially off-screen.
M# Move window # to its previous position.
s# Change the size of window #. The user is prompted to
enter the new lower right corner of the window. A box
is drawn to indicate the new window size. The same
keys used in _w and _m are used to enter the position.
S# Change window # to its previous size.
^Y Scroll the current window up by one line.
^E Scroll the current window down by one line.
^U Scroll the current window up by half the window size.
^D Scroll the current window down by half the window size.
^B Scroll the current window up by the full window size.
^F Scroll the current window down by the full window size.
h Move the cursor of the current window left by one
column.
j Move the cursor of the current window down by one line.
k Move the cursor of the current window up by one line.
l Move the cursor of the current window right by one
column.
^S Stop output in the current window.
^Q Start output in the current window.
: Enter a line to be executed as long commands. Normal
line editing characters (erase character, erase word,
erase line) are supported.
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LONG COMMANDS
Long commands are a sequence of statements parsed much like
a programming language, with a syntax similar to that of C.
Numeric and string expressions and variables are supported,
as well as conditional statements.
There are two data types: string and number. A string is a
sequence of letters or digits beginning with a letter.
``_'' and ``.'' are considered letters. Alternately, non-
alphanumeric characters can be included in strings by quot-
ing them in ``"'' or escaping them with ``\''. In addition,
the ``\'' sequences of C are supported, both inside and out-
side quotes (e.g., ``\n'' is a new line, ``\r'' a carriage
return). For example, these are legal strings: abcde01234,
"&#$^*&#", ab"$#"cd, ab\$\#cd, "/usr/ucb/window".
A number is an integer value in one of three forms: a
decimal number, an octal number preceded by ``0'', or a hex-
adecimal number preceded by ``0x'' or ``0X''. The natural
machine integer size is used (i.e., the signed integer type
of the C compiler). As in C, a non-zero number represents a
boolean true.
The character ``#'' begins a comment which terminates at the
end of the line.
A statement is either a conditional or an expression.
Expression statements are terminated with a new line or
``;''. To continue an expression on the next line, ter-
minate the first line with ``\''.
CONDITIONAL STATEMENT
_W_i_n_d_o_w has a single control structure: the fully bracketed
if statement in the form
if <expr> then
<statement>
. . .
elsif <expr> then
<statement>
. . .
else
<statement>
. . .
endif
The _e_l_s_e and _e_l_s_i_f parts are optional, and the latter can be
repeated any number of times. <_E_x_p_r> must be numeric.
EXPRESSIONS
Expressions in _w_i_n_d_o_w are similar to those in the C
language, with most C operators supported on numeric
operands. In addition, some are overloaded to operate on
strings.
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When an expression is used as a statement, its value is dis-
carded after evaluation. Therefore, only expressions with
side effects (assignments and function calls) are useful as
statements.
Single valued (no arrays) variables are supported, of both
numeric and string values. Some variables are predefined.
They are listed below.
The operators in order of increasing precedence:
<expr1> = <expr2>
Assignment. The variable of name <_e_x_p_r_1>, which must
be string valued, is assigned the result of <_e_x_p_r_2>.
Returns the value of <_e_x_p_r_2>.
<expr1> ? <expr2> : <expr3>
Returns the value of <_e_x_p_r_2> if <_e_x_p_r_1> evaluates true
(non-zero numeric value); returns the value of <_e_x_p_r_3>
otherwise. Only one of <_e_x_p_r_2> and <_e_x_p_r_3> is
evaluated. <_E_x_p_r_1> must be numeric.
<expr1> || <expr2>
Logical or. Numeric values only. Short circuit
evaluation is supported (i.e., if <_e_x_p_r_1> evaluates
true, then <_e_x_p_r_2> is not evaluated).
<expr1> && <expr2>
Logical and with short circuit evaluation. Numeric
values only.
<expr1> | <expr2>
Bitwise or. Numeric values only.
<expr1> ^ <expr2>
Bitwise exclusive or. Numeric values only.
<expr1> & <expr2>
Bitwise and. Numeric values only.
<expr1> == <expr2>, <expr1> != <expr2>
Comparison (equal and not equal, respectively). The
boolean result (either 1 or 0) of the comparison is
returned. The operands can be numeric or string
valued. One string operand forces the other to be con-
verted to a string in necessary.
<expr1> < <expr2>, <expr1> > <expr2>,
Less than, greater than, less than or equal to, greater
than or equal to. Both numeric and string values, with
automatic conversion as above.
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<expr1> << <expr2>, <expr1> >> <expr2>
If both operands are numbers, <_e_x_p_r_1> is bit shifted
left (or right) by <_e_x_p_r_2> bits. If <_e_x_p_r_1> is a
string, then its first (or last) <_e_x_p_r_2> characters are
returns (if <_e_x_p_r_2> is also a string, then its length
is used in place of its value).
<expr1> + <expr2>, <expr1> - <expr2>
Addition and subtraction on numbers. For ``+'', if one
argument is a string, then the other is converted to a
string, and the result is the concatenation of the two
strings.
<expr1> * <expr2>, <expr1> / <expr2>,
Multiplication, division, modulo. Numbers only.
-<expr>, ~<expr>, !<expr>, $<expr>, $?<expr>
The first three are unary minus, bitwise complement and
logical complement on numbers only. The operator,
``$'', takes <_e_x_p_r> and returns the value of the vari-
able of that name. If <_e_x_p_r> is numeric with value _n
and it appears within an alias macro (see below), then
it refers to the nth argument of the alias invocation.
``$?'' tests for the existence of the variable <_e_x_p_r>,
and returns 1 if it exists or 0 otherwise.
<expr>(<arglist>)
Function call. <_E_x_p_r> must be a string that is the
unique prefix of the name of a builtin _w_i_n_d_o_w function
or the full name of a user defined alias macro. In the
case of a builtin function, <_a_r_g_l_i_s_t> can be in one of
two forms:
<expr1>, <expr2>, . . .
argname1 = <expr1>, argname2 = <expr2>, . . .
The two forms can in fact be intermixed, but the result
is unpredictable. Most arguments can be omitted;
default values will be supplied for them. The _a_r_g_n_a_m_e_s
can be unique prefixes of the the argument names. The
commas separating arguments are used only to disambigu-
ate, and can usually be omitted.
Only the first argument form is valid for user defined
aliases. Aliases are defined using the _a_l_i_a_s builtin
function (see below). Arguments are accessed via a
variant of the variable mechanism (see ``$'' operator
above).
Most functions return value, but some are used for side
effect only and so must be used as statements. When a
function or an alias is used as a statement, the
parenthesis surrounding the argument list may be omit-
ted. Aliases return no value.
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BUILTIN FUNCTIONS
The arguments are listed by name in their natural order.
Optional arguments are in square brackets (``[ ]''). Argu-
ments that have no names are in angle brackets (``<>'').
alias([<string>], [<string-list>])
If no argument is given, all currently defined alias
macros are listed. Otherwise, <_s_t_r_i_n_g> is defined as
an alias, with expansion <_s_t_r_i_n_g-_l_i_s_t>. The previous
definition of <_s_t_r_i_n_g>, if any, is returned. Default
for <_s_t_r_i_n_g-_l_i_s_t> is no change.
close(<window-list>)
Close the windows specified in <_w_i_n_d_o_w-_l_i_s_t>. If
<_w_i_n_d_o_w-_l_i_s_t> is the word _a_l_l, than all windows are
closed. No value is returned.
cursormodes([modes])
Set the window cursor to _m_o_d_e_s. _M_o_d_e_s is the bitwise
or of the mode bits defined as the variables _m__u_l
(underline), _m__r_e_v (reverse video), _m__b_l_k (blinking),
and _m__g_r_p (graphics, terminal dependent). Return value
is the previous modes. Default is no change. For
example, cursor($m_rev|$m_blk) sets the window cursors
to blinking reverse video.
echo([window], [<string-list>])
Write the list of strings, <_s_t_r_i_n_g-_l_i_s_t>, to _w_i_n_d_o_w,
separated by spaces and terminated with a new line.
The strings are only displayed in the window, the
processes in the window are not involved (see _w_r_i_t_e
below). No value is returned. Default is the current
window.
escape([escapec])
Set the escape character to _e_s_c_a_p_e-_c_h_a_r. Returns the
old escape character as a one character string.
Default is no change. _E_s_c_a_p_e_c can be a string of a
single character, or in the form ^_X, meaning control-_X.
foreground([window], [flag])
Move _w_i_n_d_o_w in or out of foreground. _F_l_a_g can be one
of _o_n, _o_f_f, _y_e_s, _n_o, _t_r_u_e, or _f_a_l_s_e, with obvious mean-
ings, or it can be a numeric expression, in which case
a non-zero value is true. Returns the old foreground
flag as a number. Default for _w_i_n_d_o_w is the current
window, default for _f_l_a_g is no change.
label([window], [label])
Set the label of _w_i_n_d_o_w to _l_a_b_e_l. Returns the old
label as a string. Default for _w_i_n_d_o_w is the current
window, default for _l_a_b_e_l is no change. To turn off a
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label, set it to an empty string ("").
list()
No arguments. List the identifiers and labels of all
windows. No value is returned.
nline([nline])
Set the default buffer size to _n_l_i_n_e. Initially, it is
48 lines. Returns the old default buffer size.
Default is no change. Using a very large buffer can
slow the program down considerably.
select([window])
Make _w_i_n_d_o_w the current window. The previous current
window is returned. Default is no change.
shell([<string-list>])
Set the default window shell program to <_s_t_r_i_n_g-_l_i_s_t>.
Returns the first string in the old shell setting.
Default is no change. Initially, the default shell is
taken from the environment variable _S_H_E_L_L.
source(filename)
Read and execute the long commands in _f_i_l_e_n_a_m_e.
Returns -1 if the file cannot be read, 0 otherwise.
terse([flag])
Set terse mode to _f_l_a_g. In terse mode, the command
window stays hidden even in command mode, and errors
are reported by sounding the terminal's bell. _F_l_a_g can
take on the same values as in _f_o_r_e_g_r_o_u_n_d above.
Returns the old terse flag. Default is no change.
unalias(alias)
Undefine _a_l_i_a_s. Returns -1 if _a_l_i_a_s does not exist, 0
otherwise.
unset(variable)
Undefine _v_a_r_i_a_b_l_e. Returns -1 if _v_a_r_i_a_b_l_e does not
exist, 0 otherwise.
variables()
No arguments. List all variables. No value is
returned.
window([row], [column], [nrow], [ncol], [nline], [frame],
[pty], [mapnl], [shell])
Open a window with upper left corner at _r_o_w, _c_o_l_u_m_n and
size _n_r_o_w, _n_c_o_l. If _n_l_i_n_e is specified, then that many
lines are allocated for the text buffer. Otherwise,
the default buffer size is used. Default values for
_r_o_w, _c_o_l_u_m_n, _n_r_o_w, and _n_c_o_l are, respectively, the
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upper, left-most, lower, or right-most extremes of the
screen. _F_r_a_m_e, _p_t_y, and _m_a_p_n_l are flag values inter-
preted in the same way as the argument to _f_o_r_e_g_r_o_u_n_d
(see above); they mean, respectively, put a frame
around this window (default true), allocate pseudo-
terminal for this window rather than socketpair
(default true), and map new line characters in this
window to carriage return and line feed (default true
if socketpair is used, false otherwise). _S_h_e_l_l is a
list of strings that will be used as the shell program
to place in the window (default is the program speci-
fied by _s_h_e_l_l, see below). The created window's iden-
tifier is returned as a number.
write([window], [<string-list>])
Send the list of strings, <_s_t_r_i_n_g-_l_i_s_t>, to _w_i_n_d_o_w,
separated by spaces but not terminated with a new line.
The strings are actually given to the window as input.
No value is returned. Default is the current window.
PREDEFINED VARIABLES
These variables are for information only. Redefining them
does not affect the internal operation of _w_i_n_d_o_w.
baud The baud rate as a number between 50 and 38400.
modes
The display modes (reverse video, underline, blinking,
graphics) supported by the physical terminal. The
value of _m_o_d_e_s is the bitwise or of some of the one bit
values, _m__b_l_k, _m__g_r_p, _m__r_e_v, and _m__u_l (see below).
These values are useful in setting the window cursors'
modes (see _c_u_r_s_o_r_m_o_d_e_s above).
m_blk
The blinking mode bit.
m_grp
The graphics mode bit (not very useful).
m_rev
The reverse video mode bit.
m_ul The underline mode bit.
ncol The number of columns on the physical screen.
nrow The number of rows on the physical screen.
term The terminal type. The standard name, found in the
second name field of the terminal's _T_E_R_M_C_A_P entry, is
used.
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FILES
~/.windowrc startup command file.
/dev/[pt]ty[pq]?pseudo-terminal devices.
DIAGNOSTICS
Should be self explanatory.
BUGS
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