termcap(F) 19 June 1992 termcap(F) Name termcap - terminal capability database Description The file /etc/termcap is a database describing terminals. This database is used by packages such as vi(C), Lyrix(r), Multiplan(TM), and sub-routine packages such as curses(S). Terminals are described in termcap by giving a set of capabilities and by describing how operations are performed. Padding requirements and initialization sequences are included in termcap. Entries in termcap consist of a number of fields separated by colons (:). The first entry for each terminal gives the names that are known for the terminal, separated by vertical bars (|). For compatibility with older systems the first name is always 2 characters long. The second name given is the most common abbreviation for the terminal and the name used by vi(C) and ex(C). The last name given should be a long name fully identifying the terminal. Only the last name can contain blanks for rea- dability. Capabilities (including XENIX extensions) The following is a list of the capabilities that can be defined for a given terminal. In this list, (P) indicates that padding can be speci- fied, and (P*) indicates that padding can be based on the number of lines affected. The capability type and padding fields are described in detail in the following section ``Types of capabilities.'' The codes beginning with uppercase letters (except for CC) indicate XENIX extensions. They are included in addition to the standard entries and are used by one or more application programs. As with the standard entries, not all modes are supported by all applications or terminals. Some of these entries refer to specific terminal output capabilities (such as GS for ``graphics start''). Others describe character sequences sent by keys that appear on a keyboard (such as PU for PageUp key). There are also entries that are used to attribute special meanings to other keys (or combinations of keys) for use in a particular software program. Some of the XENIX extension capabilities have a similar func- tion to standard capabilities. They are used to redefine specific keys (such as using function keys as arrow keys). The extension capabilities are included in the /etc/termcap file, as they are required for some utilities. The more commonly used extension capabilities are described in more detail in the section ``XENIX extensions.'' Name Type Pad? Description ae str (P) End alternate character set al str (P*) Add new blank line am bool Terminal has automatic margins as str (P) Start alternate character set bc str Backspace if not ^H bs bool Terminal can backspace with ^H bt str (P) Back tab bw bool Backspace wraps from column 0 to last column CC str Command character in prototype if terminal settable cd str (P*) Clear to end of display ce str (P) Clear to end of line CF str Cursor off ch str (P) Like cm but horizontal motion only, line stays same CL str Sent by CHAR LEFT key cl str (P*) Clear screen cm str (P) Cursor motion co num Number of columns in a line CO str Cursor on cr str (P*) Carriage return, (default ^M) cs str (P) Change scrolling region (vt100), like cm cv str (P) Like ch but vertical only. CW str Sent by CHANGE WINDOW key da bool Display may be retained above DA bool Delete attribute string db bool Display may be retained below dB num Number of millisec of bs delay needed dC num Number of millisec of cr delay needed dc str (P*) Delete character dF num Number of millisec of ff delay needed dl str (P*) Delete line dm str Delete mode (enter) dN num Number of millisec of nl delay needed do str Down one line dT num Number of millisec of tab delay needed ed str End delete mode ei str End insert mode; give `:ei=:' if ic EN str Sent by END key eo bool Can erase overstrikes with a blank ff str (P*) Hardcopy terminal page eject (default ^L) G1 str Upper-right (1st quadrant) corner character G2 str Upper-left (2nd quadrant) corner character Name Type Pad? Description G3 str Lower-left (3rd quadrant) corner character G4 str Lower-right (4th quadrant) corner character GC str Center graphics character (similar to ``+'') GD str Down-tick character GE str Graphics mode end GG num Number of chars taken by GS and GE GH str Horizontal bar character GL str Left-tick character GR str Right-tick character GS str Graphics mode start GU str Up-tick character GV str Vertical bar character hc bool Hardcopy terminal hd str Half-line down (forward 1/2 linefeed) HM str Sent by HOME key (if not kh) ho str Home cursor (if no cm) hu str Half-line up (reverse 1/2 linefeed) hz str Hazeltine; can't print ~'s ic str (P) Insert character if str Name of file containing is im str Insert mode (enter); give `:im=' if ic in bool Insert mode distinguishes nulls on display ip str (P*) Insert pad after character inserted is str Terminal initialization string k0-k9 str Sent by `other' function keys 0-9 kb str Sent by backspace key kd str Sent by terminal down arrow key ke str Out of `keypad transmit' mode kh str Sent by home key kl str Sent by terminal left arrow key kn num Number of `other' keys ko str Termcap entries for other non-function keys kr str Sent by terminal right arrow key ks str Put terminal in `keypad transmit' mode ku str Sent by terminal up arrow key l0-l9 str Labels on `other' function keys LD str Sent by line delete key LF str Sent by line feed key li num Number of lines on screen or page ll str Last line, first column (if no cm) ma str Arrow key map, used by vi version 2 only mb bool Turn on flash me bool Turn off flash mi bool Safe to move while in insert mode ml str Memory lock on above cursor MP str Multiplan initialization string Name Type Pad? Description MR str Multiplan reset string ms bool Will scroll in stand-out mode mu str Memory unlock (turn off memory lock) nc bool No correctly working carriage return (DM2500,H2000) nd str Non-destructive space (cursor right) nl str (P*) Newline character (default \n) ns bool Terminal is a CRT but doesn't scroll NU str Sent by NEXT UNLOCKED CELL key os bool Terminal overstrikes pc str Pad character (rather than null) PD str Sent by PAGE DOWN key PN str Start local printing PS str End local printing pt bool Has hardware tabs (may need to be set with is) PU str Sent by PAGE UP key RC str Sent by RECALC key RF str Sent by TOGGLE REFERENCE key RT str Sent by RETURN key se str End stand out mode sf str (P) Scroll forwards sg num Number of blank chars left by so or se so str Begin stand out mode sr str (P) Scroll reverse (backwards) ta str (P) Tab (other than ^I or with padding) tc str Entry of similar terminal - must be last te str String to end programs that use cm ti str String to begin programs that use cm uc str Underscore one char and move past it ue str End underscore mode ug num Number of blank chars left by us or ue ul bool Terminal underlines even though it doesn't overstrike up str Upline (cursor up) UP str Sent by up-arrow key (alternate to ku) us str Start underscore mode vb str Visible bell (may not move cursor) ve str Sequence to end open/visual mode vs str Sequence to start open/visual mode WL str Sent by WORD LEFT key WR str Sent by WORD RIGHT key xb bool Beehive (f1=escape, f2=ctrl C) xn bool A newline is ignored after a wrap (Concept) xr bool Return acts like ce \r \n (Delta Data) xs bool Standard out not erased by writing over it (HP 264) xt bool Tabs are destructive, magic so char (Teleray 1061) A sample entry The following entry describes the Concept-100, and is among the more com- plex entries in the termcap file. (This particular Concept entry is out- dated, and is used as an example only.) c1|c100|concept100:is=\EU\Ef\E7\E5\E8\El\ENH\EK\E\200\Eo&\200:\ :al=3*\E^R:am:bs:cd=16*\E^C:ce=16\E^S:cl=2*^L:\ :cm=\Ea%+ %+ :co#80:dc=16\E^A:dl=3*\E^B:\ :ei=\E\200:eo:im=\E^P:in:ip=16*:li#24:mi:nd=\E=:\ :se=\Ed\Ee:so=\ED\EE:ta=8\t:ul:up=\E;:vb=\Ek\EK:xn: Entries may continue over to multiple lines by giving a backslash (\) as the last character of a line. Empty fields can be included for readabil- ity between the last field on a line and the first field on the next. Capabilities in termcap are of three types: Boolean capabilities, which indicate that the terminal has some particular feature, numeric capabili- ties giving the size of the terminal or the size of particular delays, and string capabilities, which give a sequence that can be used to per- form particular terminal operations. Types of capabilities All capabilities have two letter codes. For instance, the fact that the Concept has `automatic margins' (i.e., an automatic return and linefeed when the end of a line is reached) is indicated by the capability am. The description of the Concept includes am. Numeric capabilities are followed by the character ``#'' and then the value. Thus co, which indi- cates the number of columns the terminal has, gives the value `80' for the Concept. Finally, string valued capabilities, such as ce (clear to end of line sequence) are given by the two character code, an ``='', and then a string ending at the next following ``:''. A delay in milliseconds may appear after the ``='' in such a capability, and padding characters are supplied by the editor after the rest of the string is sent to provide this delay. The delay can be either an integer, for example, `20', or an integer followed by an ``*'', such as `3*'. A ``*'' indicates that the padding required is proportional to the number of lines affected by the operation, and the amount given is the per-affected-unit padding required. When a ``*'' is specified, it is sometimes useful to give a delay of the form `3.5' to specify a delay per unit to tenths of mil- liseconds. A number of escape sequences are provided in the string valued capabili- ties for easy encoding of characters there. A \E maps to an ESCAPE char- acter, ^x maps to a Control x for any appropriate x, and the sequences \n, \r, \t, \b, \f give a Newline, Return, Tab, Backspace and Formfeed. Finally, characters may be given as three octal digits after a ``\'', and the characters ``^'' and ``\'' may be given as ``\^'' and ``\\''. If it is necessary to place a colon (:) in a capability, it must be escaped in octal as \072. If it is necessary to place a null character in a string capability, it must be encoded as \200. The routines that deal with termcap use C strings, and strip the high bits of the output very late so that a \200 comes out as a \000 would. Preparing descriptions The most effective way to prepare a terminal description is by imitating the description of a similar terminal in termcap and building up a description gradually, using partial descriptions with ex to check that they are correct. Be aware that a very unusual terminal may expose defi- ciencies in the ability of the termcap file to describe it. To test a new terminal description, you can set the environment variable TERMCAP to a pathname of a file containing the description you are working on and the editor will look there rather than in /etc/termcap. TERMCAP can also be set to the termcap entry itself to avoid reading the file when start- ing up the editor. Basic capabilities The number of columns on each line for the terminal is given by the co numeric capability. If the terminal is a CRT, the number of lines on the screen is given by the li capability. If the terminal wraps around to the beginning of the next line when it reaches the right margin, it should have the am capability. If the terminal can clear its screen, this is given by the cl string capability. If the terminal can backspace, it should have the bs capability, unless a backspace is accomplished by a character other than ^H in which case you should give this character as the bc string capability. If it overstrikes (rather than clearing a posi- tion when a character is struck over), it should have the os capability. A very important point here is that the local cursor motions encoded in termcap are undefined at the left and top edges of a CRT terminal. The editor will never attempt to backspace around the left edge, nor will it attempt to go up locally off the top. The editor assumes that feeding off the bottom of the screen will cause the screen to scroll up, and the am capability tells whether the cursor sticks at the right edge of the screen. If the terminal has switch selectable automatic margins, the termcap file usually assumes that this is on (that is, am). These capabilities suffice to describe hardcopy and ``glass-tty'' termi- nals. Thus the Model 33 Teletype is described as t3|33|tty33:co#72:os while the Lear Siegler ADM-3 is described as: cl|adm3|3|lsi adm3:am:bs:cl=^Z:li#24:co#80 Cursor addressing Cursor addressing in the terminal is described by a cm string capability. This capability uses printf(S) -like escapes (such as %x) in it. These substitute to encodings of the current line or column position, while other characters are passed through unchanged. If the cm string is thought of as being a function, its arguments are the line and then the column to which motion is desired, and the ``%'' encodings have the fol- lowing meanings: %d replaced by line/column position, 0 origin %2 like %2d - 2 digit field %3 like %3d - 3 digit field %. like printf(S) %c %+x adds x to value, then %. %>xy if value > x adds y, no output %r reverses order of line and column, no output %i increments line/column position (for 1 origin) %% gives a single % %n exclusive or row and column with 0140 (DM2500) %B BCD (16*(x/10)) + (x%10), no output %D Reverse coding (x-2*(x%16)), no output (Delta Data). Consider the HP2645, which, to get to row 3 and column 12, needs to be sent \E&a12c03Y padded for 6 milliseconds. Note that the order of the rows and columns is inverted here, and that the row and column are printed as two digits. Thus its cm capability is `cm=6\E&%r%2c%2Y'. The Microterm ACT-IV needs the current row and column sent preceded by a ^T, with the row and column simply encoded in binary, `cm=^T%.%.'. Terminals that use ``%.'' need to be able to backspace the cursor (bs or bc), and to move the cursor up one line on the screen (up introduced below). This is necessary because it is not always safe to transmit \t, \n ^D and \r, as the system may change or discard them. A final example is the LSI ADM-3a, which uses row and column offset by a blank character, thus `cm=\E=%+ %+ '. Cursor motions If the terminal can move the cursor one position to the right, leaving the character at the current position unchanged, this sequence should be given as nd (non-destructive space). If it can move the cursor up a line on the screen in the same column, it should be given as up. If the ter- minal has no cursor addressing capability, but can home the cursor (to very upper left corner of screen), this can be given as ho; similarly, a fast way of getting to the lower left hand corner can be given as ll; this may involve going up with up from the home position, but the editor will never do this itself (unless ll does) because it makes no assumption about the effect of moving up from the home position. Area clears If the terminal can clear from the current position to the end of the line, leaving the cursor where it is, the sequence should be given as ce. If the terminal can clear from the current position to the end of the display, the sequence should be given as cd. The editor only uses cd from the first column of a line. Insert/delete line If the terminal can open a new blank line before the line where the cur- sor is, the sequence should be given as al. Note that this is done only from the first position of a line. The cursor must then appear on the newly blank line. If the terminal can delete the line on which the cur- sor rests, the sequence should be given as dl. This is done only from the first position on the line to be deleted. If the terminal can scroll the screen backwards, the sequence can be given as sb, but al can suffice. If the terminal can retain display memory above, the da capa- bility should be given, and if display memory can be retained below, then db should be given. These let the editor know that deleting a line on the screen may bring non-blank lines up from below or that scrolling back with sb may bring down non-blank lines. Insert/delete character There are two basic kinds of intelligent terminals with respect to the insert/delete character that can be described using termcap. The most common insert/delete character operations affect only the characters on the current line and shift characters off the end of the line. Other terminals, such as the Concept 100 and the Perkin Elmer Owl, make a dis- tinction between typed and untyped blanks on the screen, shifting upon an insert or delete only to an untyped blank on the screen which is either eliminated, or expanded to two untyped blanks. You can find out which kind of terminal you have by clearing the screen and entering text separated by cursor motions. Enter `abc def', using local cursor motions (not spaces) between the `abc' and the `def'. Then position the cursor before the `abc' and put the terminal in insert mode. If entering characters causes the rest of the line to shift rigidly and characters to fall off the end, your terminal does not distinguish between blanks and untyped positions. If the `abc' shifts over to the `def' which then move together around the end of the current line and onto the next as you insert, you have the second type of terminal, and should give the capa- bility in, which stands for `insert null'. No known terminals have an insert mode, not falling into one of these two classes. The editor can handle both terminals that have an insert mode and termi- nals that send a simple sequence to open a blank position on the current line. Specify im as the sequence to get into insert mode, or give it an empty value if your terminal uses a sequence to insert a blank position. Specify ei as the sequence to leave insert mode (specify this with an empty value if you also gave im an empty value). Now specify ic as any sequence needed to be sent just before sending the character to be inserted. Most terminals with a true insert mode will not support ic, terminals that send a sequence to open a screen position should give it here. (Insert mode is preferable to the sequence to open a position on the screen if your terminal has both.) If post insert padding is needed, give this as a number of milliseconds in ip (a string option). Any other sequence that may need to be sent after an insert of a single character may also be given in ip. It is occasionally necessary to move around while in insert mode to delete characters on the same line (for example, if there is a tab after the insertion position). If your terminal allows motion while in insert mode, you can give the capability mi to speed up inserting in this case. Omitting mi will affect only speed. Some terminals (notably Datamedia's) must not have mi because of the way their insert mode works. Finally, you can specify delete mode by giving dm and ed to enter and exit delete mode, and dc to delete a single character while in delete mode. Highlighting, underlining, and visible bells If your terminal has sequences to enter and exit standout mode, these can be given as so and se respectively. If there are several flavors of standout mode (such as reverse video, blinking, or underlining - half bright is not usually an acceptable standout mode unless the terminal is in reverse video mode constantly), the preferred mode is reverse video by itself. It is acceptable, if the code to change into or out of standout mode leaves one, or even two blank spaces on the screen, as the TVI 912 and Teleray 1061 do. Although it may confuse some programs slightly, it cannot be helped. Codes to begin and end underlining can be given as us and ue respec- tively. If the terminal has a code to underline the current character and move the cursor one space to the right, such as the Microterm Mime, the sequence can be given as uc. (If the underline code does not move the cursor to the right, specify the code followed by a nondestructive space.) If the terminal has a way of flashing the screen to indicate an error silently (a bell replacement), the sequence can be given as vb; it must not move the cursor. If the terminal should be placed in a different mode during open and visual modes of ex, the sequence can be given as vs and ve, sent at the start and end of these modes respectively. These can be used to change from a underline to a block cursor and back. If the terminal needs to be in a special mode when running a program that addresses the cursor, the codes to enter and exit this mode can be given as ti and te. This arises, for example, from terminals like the Concept with more than one page of memory. If the terminal has only memory rela- tive cursor addressing and not screen relative cursor addressing, a one screen-sized window must be fixed into the terminal for cursor addressing to work properly. If your terminal correctly generates underlined characters (with no spe- cial codes needed), even though it does not overstrike, you should give the capability ul. If overstrikes are erasable with a blank, this should be indicated by specifying eo. Keypad If the terminal has a keypad that transmits codes when the keys are pressed, this information can be given. Note that it is not possible to handle terminals where the keypad only works in local (this applies, for example, to the unshifted HP 2621 keys). If the keypad can be set to transmit or not to transmit, enter these codes as ks and ke. Otherwise, the keypad is assumed always to transmit. The codes sent by the left arrow, right arrow, up arrow, down arrow, and home keys can be given as kl, kr, ku, kd, and kh. If there are function keys such as f0, f1, ..., f9, the codes they send can be given as k0, k1, ..., k9. If there are other keys that transmit the same code as the terminal expects for the corresponding function, such as clear screen, the termcap 2 letter codes can be given in the ko capability, for example, `:ko=cl,ll,sf,sb:', which says that the terminal has clear, home down, scroll down, and scroll up keys that transmit the same thing as the cl, ll, sf, and sb entries. The ma entry is also used to indicate arrow keys on terminals which have single character arrow keys. It is obsolete, but still in use in version 2 of vi, which must be run on some minicomputers due to memory limita- tions. This field is redundant with kl, kr, ku, kd, and kh. It con- sists of groups of two characters. In each group, the first character is what an arrow key sends, the second character is the corresponding vi command. These commands are h for kl, j for kd, k for ku, l for kr, and H for kh. For example, the Mime would be :ma=^Kj^Zk^Xl: indicating arrow keys left (^H), down (^K), up (^Z), and right (^X). (There is no home key on the Mime.) Miscellaneous If the terminal requires other than a null (zero) character as a pad, this can be given as pc. If tabs on the terminal require padding, or if the terminal uses a char- acter other than ^I to tab, the sequence can be given as ta. Terminals that do not allow ``~'' characters to be displayed (such as Hazeltines), should indicate hz. Datamedia terminals that echo carriage-return-linefeed for carriage return, and then ignore a following linefeed, should indicate nc. Early Concept terminals, that ignore a linefeed immediately after an am wrap, should indicate xn. If an erase- eol is required to get rid of standout (instead of merely writing on top of it), xs should be given. Teleray terminals, where tabs turn all char- acters moved over to blanks, should indicate xt. Other specific terminal problems may be corrected by adding more capabilities of the form xx. If the leading character for commands to the terminal (normally the escape character) can be set by the software, specify the command character(s) with the capability CC. Other capabilities include is, an initialization string for the terminal, and if, the name of a file containing long initialization strings. These strings are expected to properly clear and then set the tabs on the ter- minal, if the terminal has settable tabs. If both are given, is is dis- played before if. This is useful where if is /usr/lib/tabset/std, but is clears the tabs first. Similar terminals If there are two very similar terminals, one can be defined as being just like the other with certain exceptions. The string capability, tc, can be given with the name of the similar terminal. This capability must be last and the combined length of the two entries must not exceed 1024. Since termlib routines search the entry from left to right, and since the tc capability is replaced by the corresponding entry, the capabilities given at the left override the ones in the similar terminal. A capabil- ity can be canceled with xx@ where xx is the capability. For example: hn|2621nl:ks@:ke@:tc=2621: This defines a 2621nl that does not have the ks or ke capabilities, and does not turn on the function key labels when in visual mode. This is useful for different modes for a terminal, or for different user prefer- ences. XENIX extensions Capabilities This table lists the (previously listed) XENIX extensions to the termcap capabilities. It shows which codes generate information input from the keyboard to the program reading the keyboard and which codes generate in- formation output from the program to the screen. Name Input/Output Description CF str Cursor off CL str Sent by CHAR LEFT key CO str Cursor on CW str Sent by CHANGE WINDOW key DA bool Delete attribute string EN str Sent by END key G1 str Upper-right (1st quadrant) corner character G2 str Upper-left (2nd quadrant) corner character G3 str Lower-left (3rd quadrant) corner character G4 str Lower-right (4th quadrant) corner character G5 str Upper right (1st quadrant) corner character (double) G6 str Upper left (2nd quadrant) corner character (double) G7 str Lower left (3rd quadrant) corner character (double) G8 str Lower right (4th quadrant) corner character (double) GC str Center graphics character (similar to +) Gc str Centre graphics character (double) GD str Down-tick character Gd str Down tick character (double) GE str Graphics mode end GG num Number of chars taken by GS and GE GH str Horizontal bar character Gh str Horizontal bar character (double) GL str Left-tick character Gl str left-tick character (double) GR str Right-tick character Gr str right-tick character (double) GS str Graphics mode start GU str Up-tick character Gu str Up-tick character (double) GV str Vertical bar character Gv str Vertical bar character (double) HM str Sent by HOME key (if not kh) mb str blinking on me str blinking off MP str Multiplan initialization string MR str Multiplan reset string NU str Sent by NEXT UNLOCKED CELL key PD str Sent by PAGE DOWN key PU str Sent by PAGE UP key RC str Sent by RECALC key RF str Sent by TOGGLE REFERENCE key RT str Sent by RETURN key UP str Sent by up-arrow key (alternate to ku) WL str Sent by WORD LEFT key WR str Sent by WORD RIGHT key Cursor motion Some application programs make use of special editing codes. CR and CL move the cursor one character right and left respectively. WR and WL move the cursor one word right and left respectively. CW changes windows, when they are used in the program. Some application programs turn off the cursor. This is accomplished using CF for cursor off and CO to turn it back on. Graphic mode If the terminal has graphics capabilities, this mode can be turned on and off with the GS and GE codes. Some terminals generate graphics charac- ters from all keys when in graphics mode (such as the Visual 50). The other G codes specify particular graphics characters accessed by escape sequences. These characters are available on some terminals as alternate graphics character sets (not as a bit-map graphic mode). The vt100 has access to this kind of alternate graphics character set, but not to a bit-map graphic mode. File /etc/termcap File containing terminal descriptions See also ex(C), curses(S), more(C), screen(HW), termcap(S), tset(C), vi(C) Credit This utility was developed at the University of California at Berkeley and is used with permission. Notes ex(C) allows only 256 characters for string capabilities, and the rou- tines in termcap(S) do not check for overflow of this buffer. The total length of a single entry (excluding only escaped newlines) may not exceed 1024. The ma, vs, and ve entries are specific to the vi(C) program. Not all programs support all entries. There are entries that are not supported by any program. XENIX termcap extensions are explained in detail in the software applica- tion documentation. Refer to the screen(HW) manual page, for a description of the character sequences used by the monitor device on your specific system.