1.\" Copyright (c) 1985, 1990 The Regents of the University of California. 2.\" All rights reserved. 3.\" 4.\" This code is derived from software contributed to Berkeley by 5.\" Edward Wang at The University of California, Berkeley. 6.\" 7.\" %sccs.include.redist.roff% 8.\" 9.\" @(#)window.1 6.15 (Berkeley) 07/26/91 10.\" 11.Dd 12.Dt WINDOW 1 13.Os BSD 4.3 14.Sh NAME 15.Nm window 16.Nd window environment 17.Sh SYNOPSIS 18.Nm window 19.Op Fl t 20.Op Fl f 21.Op Fl d 22.Op Fl e Ar escape-char 23.Op Fl c Ar command 24.Sh DESCRIPTION 25.Nm Window 26implements a window environment on 27.Tn ASCII 28terminals. 29.Pp 30A window is a rectangular portion of the physical terminal 31screen associated with a set of processes. Its size and 32position can be changed by the user at any time. Processes 33communicate with their window in the same way they normally 34interact with a terminal\-through their standard input, output, 35and diagnostic file descriptors. The window program handles the 36details of redirecting input an output to and from the 37windows. At any one time, only one window can receive 38input from the keyboard, but all windows can simultaneously send output 39to the display. 40.Pp 41When 42.Nm window 43starts up, the commands (see long commands below) 44contained in the file 45.Pa .windowrc 46in the user's home directory are 47executed. If it does not exist, two equal sized windows spanning 48the terminal screen are created by default. 49.Pp 50The command line options are 51.Bl -tag -width Fl 52.It Fl t 53Turn on terse mode (see 54.Ic terse 55command below). 56.It Fl f 57Fast. Don't perform any startup action. 58.It Fl d 59Ignore 60.Pa .windowrc 61and create the two default 62windows instead. 63.It Fl e Ar escape-char 64Set the escape character to 65.Ar escape-char . 66.Ar Escape-char 67can be a single character, or in the form 68.Ic ^X 69where 70.Ar X 71is any character, meaning 72.No control\- Ns Ar X . 73.It Fl c Ar command 74Execute the string 75.Ar command 76as a long command (see below) 77before doing anything else. 78.El 79.Pp 80Windows can overlap and are framed as necessary. Each window 81is named by one of the digits ``1'' to ``9''. This one-character 82identifier, as well as a user definable label string, are displayed 83with the window on the top edge of its frame. A window can be 84designated to be in the 85.Ar foreground , 86in which case it will always be 87on top of all normal, non-foreground windows, and can be covered 88only by other foreground windows. A window need not be completely 89within the edges of the terminal screen. Thus a large window 90(possibly larger than the screen) may be positioned to show only 91a portion of its full size. 92.Pp 93Each window has a cursor and a set of control functions. Most intelligent 94terminal operations such as line and 95character deletion and insertion are supported. Display modes 96such as underlining and reverse video are available if they are 97supported by the terminal. In addition, 98similar to terminals with multiple pages of memory, 99each window has a text buffer which can have more lines than the window 100itself. 101.Ss Process Environment 102With each newly created window, a shell program is spawned with its 103process environment tailored to that window. Its standard input, 104output, and diagnostic file descriptors are bound to one end of either 105a pseudo-terminal 106.Xr (pty 4 ) 107or a 108.Ux 109domain socket 110.Xr (socketpair 4 ) . 111If a pseudo-terminal is used, then its special 112characters and modes (see 113.Xr stty 1 ) 114are copied from the physical 115terminal. A 116.Xr termcap 5 117entry tailored to this window is created 118and passed as environment 119.Xr (environ 5 ) 120variable 121.Ev TERMCAP . 122The termcap entry contains the window's size and 123characteristics as well as information from the physical terminal, 124such as the existence of underline, reverse video, and other display 125modes, and the codes produced by the terminal's function keys, 126if any. In addition, the window size attributes of the pseudo-terminal 127are set to reflect the size of this window, and updated whenever 128it is changed by the user. In particular, the editor 129.Xr vi 1 130uses 131this information to redraw its display. 132.Ss Operation 133During normal execution, 134.Nm window 135can be in one of two states: 136conversation mode and command mode. In conversation mode, the 137terminal's real cursor is placed at the cursor position of a particular 138window--called the current window--and input from the keyboard is sent 139to the process in that window. The current window is always 140on top of all other windows, except those in foreground. In addition, 141it is set apart by highlighting its identifier and label in reverse video. 142.Pp 143Typing 144.Nm window Ns 's 145escape character (normally 146.Ic ^P ) 147in conversation 148mode switches it into command mode. In command mode, the top line of 149the terminal screen becomes the command prompt window, and 150.Nm window 151interprets input from the keyboard as commands to manipulate windows. 152.Pp 153There are two types of commands: short commands are usually one or two 154key strokes; long commands are strings either typed by the user in the 155command window (see the 156.Dq Ic \&: 157command below), or read from a file (see 158.Ic source 159below). 160.Ss Short Commands 161Below, 162.Ar \&# 163represents one of the digits ``1'' to ``9'' 164corresponding to the windows 1 to 9. 165.Ic ^X 166means 167.No control\- Ns Ar X , 168where 169.Ar X 170is any character. In particular, 171.Ic ^^ 172is 173.Li control\-^. 174.Ar Escape 175is the escape key, or 176.Ic ^\&[ . 177.Bl -tag -width Ds 178.It Ar # 179Select window 180.Ar # 181as the current window 182and return to conversation mode. 183.It Ic \&% Ns Ar # 184Select window 185.Ar # 186but stay in command mode. 187.It Ic ^^ 188Select the previous window and return to conversation 189mode. This is useful for toggling between two windows. 190.It Ic escape 191Return to conversation mode. 192.It Ic ^P 193Return to conversation mode and write 194.Ic ^P 195to the 196current window. Thus, typing two 197.Ic ^P Ns 's 198in conversation 199mode sends one to the current window. If the 200.Nm window 201escape is changed to some other character, that 202character takes the place of 203.Ic ^P 204here. 205.It Ic ? 206List a short summary of commands. 207.It Ic ^L 208Refresh the screen. 209.It Ic q 210Exit 211.Nm window . 212Confirmation is requested. 213.It Ic ^Z 214Suspend 215.Nm window . 216.It Ic w 217Create a new window. The user is prompted for the positions 218of the upper left and lower right corners of the window. 219The cursor is placed on the screen and the keys ``h'', ``j'', 220``k'', and ``l'' 221move the cursor left, down, up, and right, respectively. 222The keys ``H'', ``J'', ``K'', and ``L'' move the cursor to the respective 223limits of the screen. Typing a number before the movement keys 224repeats the movement that number of times. Return enters the cursor position 225as the upper left corner of the window. The lower right corner 226is entered in the same manner. During this process, 227the placement of the new window is indicated by a rectangular 228box drawn on the screen, corresponding to where the new window 229will be framed. Typing escape at any point 230cancels this command. 231.Pp 232This window becomes the current window, 233and is given the first available ID. The default buffer size 234is used (see 235.Ar default_nline 236command below). 237.Pp 238Only fully visible windows can be created this way. 239.It Ic c Ns Ar # 240Close window 241.Ar # . 242The process in the window is sent 243the hangup signal (see 244.Xr kill 1 ) . 245.Xr Csh 1 246should 247handle this signal correctly and cause no problems. 248.It Ic m Ns Ar # 249Move window 250.Ar # 251to another location. A box in the shape 252of the window is drawn on 253the screen to indicate the new position of the window, and the same keys as 254those for the 255.Ic w 256command are used to position the box. The 257window can be moved partially off-screen. 258.It Ic M Ns Ar # 259Move window 260.Ar # 261to its previous position. 262.It Ic s Ns Ar # 263Change the size of window 264.Ar # . 265The user is prompted 266to enter the new lower right corner of the window. A box 267is drawn to indicate the new window size. The same 268keys used in 269.Ic w 270and 271.Ic m 272are used to enter the position. 273.It Ic S Ns Ar # 274Change window 275.Ar # 276to its previous size. 277.It Ic ^Y 278Scroll the current window up by one line. 279.It Ic ^E 280Scroll the current window down by one line. 281.It Ic ^U 282Scroll the current window up by half the window size. 283.It Ic ^D 284Scroll the current window down by half the window size. 285.It Ic ^B 286Scroll the current window up by the full window size. 287.It Ic ^F 288Scroll the current window down by the full window size. 289.It Ic h 290Move the cursor of the current window left by one column. 291.It Ic j 292Move the cursor of the current window down by one line. 293.It Ic k 294Move the cursor of the current window up by one line. 295.It Ic l 296Move the cursor of the current window right by one column. 297.It Ic ^S 298Stop output in the current window. 299.It Ic ^Q 300Start output in the current window. 301.It Ic : 302Enter a line to be executed as long commands. 303Normal line 304editing characters (erase character, erase word, erase line) 305are supported. 306.El 307.Ss Long Commands 308Long commands are a sequence of statements 309parsed much like a programming language, with a syntax 310similar to that of C. Numeric and string expressions and variables 311are supported, as well as conditional statements. 312.Pp 313There are two data types: string and number. A string is a sequence 314of letters or digits beginning with a letter. ``_'' and ``.'' are 315considered letters. Alternately, non-alphanumeric characters can 316be included in strings by quoting them in ``"'' or escaping them 317with ``\\''. In addition, the ``\\'' sequences of C are supported, 318both inside and outside quotes (e.g., ``\\n'' is a new line, 319``\\r'' a carriage return). For example, these are legal strings: 320abcde01234, "&#$^*&#", ab"$#"cd, ab\\$\\#cd, "/usr/ucb/window". 321.Pp 322A number is an integer value in one of three forms: 323a decimal number, an octal number preceded by ``0'', 324or a hexadecimal number preceded by ``0x'' or ``0X''. The natural 325machine integer size is used (i.e., the signed integer type 326of the C compiler). As in C, a non-zero number represents 327a boolean true. 328.Pp 329The character ``#'' begins a comment which terminates at the 330end of the line. 331.Pp 332A statement is either a conditional or an expression. Expression 333statements are terminated with a new line or ``;''. To continue 334an expression on the next line, terminate the first line with ``\\''. 335.Ss Conditional Statement 336.Nm Window 337has a single control structure: 338the fully bracketed if statement in the form 339.Pp 340.Bd -literal -offset indent -compact 341if <expr> then 342\t<statement> 343\t... 344elsif <expr> then 345\t<statement> 346\t... 347else 348\t<statement> 349\t... 350endif 351.Ed 352.Pp 353The 354.Ic else 355and 356.Ic elsif 357parts are optional, and the latter can 358be repeated any number of times. 359<Expr> 360must be numeric. 361.Ss Expressions 362Expressions in 363.Nm window 364are similar to those in the 365C language, with most C operators supported on numeric 366operands. In addition, some are overloaded to operate on strings. 367.Pp 368When an expression is used as a statement, its value is discarded 369after evaluation. Therefore, only expressions with side 370effects (assignments and function calls) are useful as statements. 371.Pp 372Single valued (no arrays) variables are supported, of both 373numeric and string values. Some variables are predefined. They 374are listed below. 375.Pp 376The operators in order of increasing precedence: 377.Bl -tag -width Fl 378.It Xo 379.Aq Va expr1 380.Ic = 381.Aq Va expr2 382.Xc 383Assignment. The variable of name 384.Aq Va expr1 , 385which must be string valued, 386is assigned the result of 387.Aq Va expr2 . 388Returns the value of 389.Aq Va expr2 . 390.It Xo 391.Aq Va expr1 392.Ic ? 393.Aq Va expr2 394.Ic : 395.Aq Va expr3 396.Xc 397Returns the value of 398.Aq Va expr2 399if 400.Aq Va expr1 401evaluates true 402(non-zero numeric value); returns the value of 403.Aq Va expr3 404otherwise. Only 405one of 406.Aq Va expr2 407and 408.Aq Va expr3 409is evaluated. 410.Aq Va Expr1 411must 412be numeric. 413.It Xo 414.Aq Va expr1 415.Ic \&|\&| 416.Aq Va expr2 417.Xc 418Logical or. Numeric values only. Short circuit evaluation is supported 419(i.e., if 420.Aq Va expr1 421evaluates true, then 422.Aq Va expr2 423is not evaluated). 424.It Xo 425.Aq Va expr1 426.Ic \&&\&& 427.Aq Va expr2 428.Xc 429Logical and with short circuit evaluation. Numeric values only. 430.It Xo 431.Aq Va expr1 432.Ic \&| 433.Aq Va expr2 434.Xc 435Bitwise or. Numeric values only. 436.It Xo 437.Aq Va expr1 438.Ic ^ 439.Aq Va expr2 440.Xc 441Bitwise exclusive or. Numeric values only. 442.It Xo 443.Aq Va expr1 444.Ic \&& 445.Aq Va expr2 446.Xc 447Bitwise and. Numeric values only. 448.It Xo 449.Aq Va expr1 450.Ic == 451.Aq Va expr2 , 452.Aq Va expr1 453.Ic != 454.Aq expr2 455.Xc 456Comparison (equal and not equal, respectively). The boolean 457result (either 1 or 0) of the comparison is returned. The 458operands can be numeric or string valued. One string operand 459forces the other to be converted to a string in necessary. 460.It Xo 461.Aq Va expr1 462.Ic < 463.Aq Va expr2 , 464.Aq Va expr1 465.Ic > 466.Aq Va expr2 , 467.Aq Va expr1 468.Ic <= 469.Aq Va expr2 , 470.Xc 471Less than, greater than, less than or equal to, 472greater than or equal to. Both numeric and string values, with 473automatic conversion as above. 474.It Xo 475.Aq Va expr1 476.Ic << 477.Aq Va expr2 , 478.Aq Va expr1 479.Ic >> 480.Aq Va expr2 481.Xc 482If both operands are numbers, 483.Aq Va expr1 484is bit 485shifted left (or right) by 486.Aq Va expr2 487bits. If 488.Aq Va expr1 489is 490a string, then its first (or last) 491.Aq Va expr2 492characters are 493returns (if 494.Aq Va expr2 495is also a string, then its length is used 496in place of its value). 497.It Xo 498.Aq Va expr1 499.Ic + 500.Aq Va expr2 , 501.Aq Va expr1 502.Ic - 503.Aq Va expr2 504.Xc 505Addition and subtraction on numbers. For ``+'', if one 506argument is a string, then the other is converted to a string, 507and the result is the concatenation of the two strings. 508.It Xo 509.Aq Va expr1 510.Ic \&* 511.Aq Va expr2 , 512.Aq Va expr1 513.Ic \&/ 514.Aq Va expr2 , 515.Aq Va expr1 516.Ic \&% 517.Aq Va expr2 518.Xc 519Multiplication, division, modulo. Numbers only. 520.It Xo 521.Ic \- Ns Aq Va expr , 522.Ic ~ Ns Aq Va expr , 523.Ic \&! Ns Aq Va expr , 524.Ic \&$ Ns Aq Va expr , 525.Ic \&$? Ns Aq Va expr 526.Xc 527The first three are unary minus, bitwise complement and logical complement 528on numbers only. The operator, ``$'', takes 529.Aq Va expr 530and returns 531the value of the variable of that name. If 532.Aq Va expr 533is numeric 534with value 535.Ar n 536and it appears within an alias macro (see below), 537then it refers to the nth argument of the alias invocation. ``$?'' 538tests for the existence of the variable 539.Aq Va expr , 540and returns 1 541if it exists or 0 otherwise. 542.It Xo 543.Ao Va expr Ac Ns Pq Aq Ar arglist 544.Xc 545Function call. 546.Aq Va Expr 547must be a string that is the unique 548prefix of the name of a builtin 549.Nm window 550function 551or the full name of a user defined alias macro. In the case of a builtin 552function, 553.Aq Ar arglist 554can be in one of two forms: 555.Bd -literal -offset indent 556<expr1>, <expr2>, ... 557argname1 = <expr1>, argname2 = <expr2>, ... 558.Ed 559.Pp 560The two forms can in fact be intermixed, but the result is 561unpredictable. Most arguments can be omitted; default values will 562be supplied for them. The 563.Ar argnames 564can be unique prefixes 565of the the argument names. The commas separating 566arguments are used only to disambiguate, and can usually be omitted. 567.Pp 568Only the first argument form is valid for user defined aliases. Aliases 569are defined using the 570.Ic alias 571builtin function (see below). Arguments 572are accessed via a variant of the variable mechanism (see ``$'' operator 573above). 574.Pp 575Most functions return value, but some are used for side effect 576only and so must be used as statements. When a function or an alias is used 577as a statement, the parenthesis surrounding 578the argument list may be omitted. Aliases return no value. 579.El 580.Ss Builtin Functions 581The arguments are listed by name in their natural 582order. Optional arguments are in square brackets 583.Sq Op . 584Arguments 585that have no names are in angle brackets 586.Sq <> . 587An argument meant to be a boolean flag (often named 588.Ar flag ) 589can be one of 590.Ar on , 591.Ar off , 592.Ar yes , 593.Ar no , 594.Ar true , 595or 596.Ar false , 597with 598obvious meanings, or it can be a numeric expression, 599in which case a non-zero value is true. 600.Bl -tag -width Fl 601.It Xo 602.Ic alias Ns Po Bq Aq Ar string , 603.Bq Aq Ar string\-list Pc 604.Xc 605If no argument is given, all currently defined alias macros are 606listed. Otherwise, 607.Aq Ar string 608is defined as an alias, 609with expansion 610.Aq Ar string\-list > . 611The previous definition of 612.Aq Ar string , 613if any, is returned. Default for 614.Aq Ar string\-list 615is no change. 616.It Ic close Ns Pq Aq Ar window\-list 617Close the windows specified in 618.Aq Ar window\-list . 619If 620.Aq Ar window\-list 621is the word 622.Ar all , 623than all windows are closed. No value is returned. 624.It Ic cursormodes Ns Pq Bq Ar modes 625Set the window cursor to 626.Ar modes . 627.Ar Modes 628is the bitwise 629or of the mode bits defined as the variables 630.Ar m_ul 631(underline), 632.Ar m_rev 633(reverse video), 634.Ar m_blk 635(blinking), 636and 637.Ar m_grp 638(graphics, terminal dependent). Return 639value is the previous modes. Default is no change. 640For example, 641.Li cursor($m_rev$m_blk) 642sets the window cursors to blinking 643reverse video. 644.It Ic default_nline Ns Pq Bq Ar nline 645Set the default buffer size to 646.Ar nline . 647Initially, it is 64848 lines. Returns the old default buffer size. Default is 649no change. Using a very large buffer can slow the program down 650considerably. 651.It Ic default_shell Ns Pq Bq Aq Ar string\-list 652Set the default window shell program to 653.Aq Ar string\-list . 654Returns 655the first string in the old shell setting. Default is no change. Initially, 656the default shell is taken from the environment variable 657.Ev SHELL . 658.It Ic default_smooth Ns Pq Bq Ar flag 659Set the default value of the 660.Ar smooth 661argument 662to the command 663.Nm window 664(see below). The argument 665is a boolean flag (one of 666.Ar on , 667.Ar off , 668.Ar yes , 669.Ar no , 670.Ar true , 671.Ar false , 672or a number, 673as described above). Default is no change. 674The old value (as a number) is returned. 675The initial value is 1 (true). 676.It Xo 677.Ic echo Ns ( Op Ar window , 678.Bq Aq Ar string\-list ) 679.Xc 680Write the list of strings, 681.Aq Ar string-list , 682to 683.Nm window , 684separated 685by spaces and terminated with a new line. The strings are only 686displayed in the window, the processes in the window are not 687involved (see 688.Ic write 689below). No value is returned. Default 690is the current window. 691.It Ic escape Ns Pq Bq Ar escapec 692Set the escape character to 693.Ar escape-char . 694Returns the old 695escape character as a one-character string. Default is no 696change. 697.Ar Escapec 698can be a string of a single character, or 699in the form 700.Fl ^X , 701meaning 702.No control\- Ns Ar X . 703.It Xo 704.Ic foreground Ns ( Bq Ar window , 705.Bq Ar flag ) 706.Xc 707Move 708.Nm window 709in or out of foreground. 710.Ar Flag 711is a boolean value. The old foreground flag 712is returned. Default for 713.Nm window 714is the current window, 715default for 716.Ar flag 717is no change. 718.It Xo 719.Ic label Ns ( Bq Ar window , 720.Bq Ar label ) 721.Xc 722Set the label of 723.Nm window 724to 725.Ar label . 726Returns the old 727label as a string. Default for 728.Nm window 729is the current 730window, default for 731.Ar label 732is no change. To turn 733off a label, set it to an empty string (""). 734.It Ic list Ns Pq 735No arguments. List the identifiers and labels of all windows. No 736value is returned. 737.It Ic select Ns Pq Bq Ar window 738Make 739.Nm window 740the current window. The previous current window 741is returned. Default is no change. 742.It Ic source Ns Pq Ar filename 743Read and execute the long commands in 744.Ar filename . 745Returns \-1 if the file cannot be read, 0 otherwise. 746.It Ic terse Ns Pq Bq flag 747Set terse mode to 748.Ar flag . 749In terse mode, the command window 750stays hidden even in command mode, and errors are reported by 751sounding the terminal's bell. 752.Ar Flag 753can take on the same 754values as in 755.Ar foreground 756above. Returns the old terse flag. 757Default is no change. 758.It Ic unalias Ns Pq Ar alias 759Undefine 760.Ar alias . 761Returns -1 if 762.Ar alias 763does not exist, 7640 otherwise. 765.It Ic unset Ns Pq Ar variable 766Undefine 767.Ar variable . 768Returns -1 if 769.Ar variable 770does not exist, 7710 otherwise. 772.It Ic variables Ns Pq 773No arguments. List all variables. No value is returned. 774.It Xo 775.Ic window Ns ( Bq Ar row , 776.Bq Ar column , 777.Bq Ar nrow , 778.Bq Ar ncol , 779.Bq Ar nline , 780.Bq Ar label , 781.Bq Ar pty , 782.Bq Ar frame , 783.Bq Ar mapnl , 784.Bq Ar keepopen , 785.Bq Ar smooth , 786.Bq Ar shell ) . 787.Xc 788Open a window with upper left corner at 789.Ar row , 790.Ar column 791and size 792.Ar nrow , 793.Ar ncol . 794If 795.Ar nline 796is specified, 797then that many lines are allocated for the text buffer. Otherwise, 798the default buffer size is used. Default values for 799.Ar row , 800.Ar column , 801.Ar nrow , 802and 803.Ar ncol 804are, respectively, 805the upper, left-most, lower, or right-most extremes of the 806screen. 807.Ar Label 808is the label string. 809.Ar Frame , 810.Ar pty , 811and 812.Ar mapnl 813are flag values 814interpreted in the same way as the argument to 815.Ar foreground 816(see above); 817they mean, respectively, put a frame around this window (default true), 818allocate pseudo-terminal for this window rather than socketpair (default 819true), and map new line characters in this window to carriage return 820and line feed (default true if socketpair is used, false otherwise). 821Normally, a window is automatically closed when its process 822exits. Setting 823.Ar keepopen 824to true (default false) prevents this 825action. When 826.Ar smooth 827is true, the screen is updated more frequently 828(for this window) to produce a more terminal-like behavior. 829The default value of 830.Ar smooth 831is set by the 832.Ar default_smooth 833command (see above). 834.Ar Shell 835is a list of strings that will be used as the shell 836program to place in the window (default is the program specified 837by 838.Ar default_shell , 839see above). The created window's identifier 840is returned as a number. 841.It Xo 842.Ic write Ns ( Bq Ar window , 843.Bq Aq Ar string\-list ) 844.Xc 845Send the list of strings, 846.Aq Ar string-list , 847to 848.Nm window , 849separated 850by spaces but not terminated with a new line. The strings are actually 851given to the window as input. No value is returned. Default 852is the current window. 853.El 854.Ss Predefined Variables 855These variables are for information only. Redefining them does 856not affect the internal operation of 857.Nm window . 858.Bl -tag -width modes 859.It Ar baud 860The baud rate as a number between 50 and 38400. 861.It Ar modes 862The display modes (reverse video, underline, blinking, graphics) 863supported by the physical terminal. The value of 864.Ar modes 865is the bitwise or of some of the one bit values, 866.Ar m_blk , 867.Ar m_grp , 868.Ar m_rev , 869and 870.Ar m_ul 871(see below). 872These values are useful 873in setting the window cursors' modes (see 874.Ar cursormodes 875above). 876.It Ar m_blk 877The blinking mode bit. 878.It Ar m_grp 879The graphics mode bit (not very useful). 880.It Ar m_rev 881The reverse video mode bit. 882.It Ar m_ul 883The underline mode bit. 884.It Ar ncol 885The number of columns on the physical screen. 886.It Ar nrow 887The number of rows on the physical screen. 888.It Ar term 889The terminal type. The standard name, found in the second name 890field of the terminal's 891.Ev TERMCAP 892entry, is used. 893.Sh ENVIRONMENT 894.Nm Window 895utilizes these environment variables: 896.Ev HOME , 897.Ev SHELL , 898.Ev TERM , 899.Ev TERMCAP , 900.Ev WINDOW_ID . 901.Sh FILES 902.Bl -tag -width /dev/[pt]ty[pq]? -compact 903.It Pa ~/.windowrc 904startup command file. 905.It Pa /dev/[pt]ty[pq]? 906pseudo-terminal devices. 907.El 908.Sh HISTORY 909The 910.Nm window 911command appeared in 912.Bx 4.3 . 913.Sh DIAGNOSTICS 914Should be self explanatory. 915