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). Printed 11/26/99 May 12, 1986 1 WINDOW(1) UNIX Programmer's Manual WINDOW(1) -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 Printed 11/26/99 May 12, 1986 2 WINDOW(1) UNIX Programmer's Manual WINDOW(1) 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 Printed 11/26/99 May 12, 1986 3 WINDOW(1) UNIX Programmer's Manual WINDOW(1) 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. Printed 11/26/99 May 12, 1986 4 WINDOW(1) UNIX Programmer's Manual WINDOW(1) 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 then . . . elsif then . . . else . . . 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. Printed 11/26/99 May 12, 1986 5 WINDOW(1) UNIX Programmer's Manual WINDOW(1) 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: = 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>. ? : 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. || 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). && Logical and with short circuit evaluation. Numeric values only. | Bitwise or. Numeric values only. ^ Bitwise exclusive or. Numeric values only. & Bitwise and. Numeric values only. == , != 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. < , > , Less than, greater than, less than or equal to, greater than or equal to. Both numeric and string values, with automatic conversion as above. Printed 11/26/99 May 12, 1986 6 WINDOW(1) UNIX Programmer's Manual WINDOW(1) << , >> 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). + , - 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. * , / , Multiplication, division, modulo. Numbers only. -, ~, !, $, $? The first three are unary minus, bitwise complement and logical complement on numbers only. The operator, ``$'', 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. ``$?'' tests for the existence of the variable <_e_x_p_r>, and returns 1 if it exists or 0 otherwise. () Function call. <_E_x_p_r> must be a string that is the unique prefix of the name of a builtin _w_i_n_d_o_w function or the full name of a user defined alias macro. In the case of a builtin function, <_a_r_g_l_i_s_t> can be in one of two forms: , , . . . argname1 = , argname2 = , . . . The two forms can in fact be intermixed, but the result is unpredictable. Most arguments can be omitted; default values will be supplied for them. The _a_r_g_n_a_m_e_s can be unique prefixes of the the argument names. The commas separating arguments are used only to disambigu- ate, and can usually be omitted. Only the first argument form is valid for user defined aliases. Aliases are defined using the _a_l_i_a_s builtin function (see below). Arguments are accessed via a variant of the variable mechanism (see ``$'' 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. Printed 11/26/99 May 12, 1986 7 WINDOW(1) UNIX Programmer's Manual WINDOW(1) 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([], []) 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() 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], []) 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 Printed 11/26/99 May 12, 1986 8 WINDOW(1) UNIX Programmer's Manual WINDOW(1) 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([]) 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 Printed 11/26/99 May 12, 1986 9 WINDOW(1) UNIX Programmer's Manual WINDOW(1) 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], []) 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. Printed 11/26/99 May 12, 1986 10 WINDOW(1) UNIX Programmer's Manual WINDOW(1) FILES ~/.windowrc startup command file. /dev/[pt]ty[pq]?pseudo-terminal devices. DIAGNOSTICS Should be self explanatory. BUGS Printed 11/26/99 May 12, 1986 11