Linux "terminfo" Command Line Options and Examples
terminal capability data base

Terminfo is a data base describing terminals, used by screen-oriented programs such as nvi(1), rogue(1) and libraries such as ncurses(3NCURSES). Terminfo describes terminals by giving a set of capabilities which they have, by specifying how to perform screen operations, and by specifying padding requirements and initializa‐ tion sequences.



Command Line Options:

Number of lines on the screen aaa-60
terminfo -nn ...
Number of pages of memory c100-4p
terminfo -np ...
With automargins (usually the default) vt100-am
terminfo -am ...
Mono mode; suppress color ansi-m
terminfo -m ...
Magic cookie; spaces when highlighting wy30-mc
terminfo -mc ...
No arrow keys (leave them in local) c100-na
terminfo -na ...
Without automatic margins vt100-nam
terminfo -nam ...
No status line att4415-nl
terminfo -nl ...
No status line hp2626-ns
terminfo -ns ...
Reverse video c100-rv
terminfo -rv ...
Enable status line vt100-s
terminfo -s ...
Use visible bell instead of beep wy370-vb
terminfo -vb ...
For more on terminal naming conventions, see the term(7) manual page.Terminfo Capabilities SyntaxThe terminfo entry consists of several capabilities, i.e., features that the terminal has, or methods forexercising the terminal's features.After the first field (giving the name(s) of the terminal entry), there should be one or more capabilityfields. These are boolean, numeric or string names with corresponding values:· Boolean capabilities are true when present, false when absent. There is no explicit value for booleancapabilities.· Numeric capabilities have a “#” following the name, then an unsigned decimal integer value.· String capabilities have a “=” following the name, then an string of characters making up the capabilityvalue.String capabilities can be split into multiple lines, just as the fields comprising a terminal entry canbe split into multiple lines. While blanks between fields are ignored, blanks embedded within a stringvalue are retained, except for leading blanks on a line.Any capability can be canceled, i.e., suppressed from the terminal entry, by following its name with “@”rather than a capability value.Similar TerminalsIf there are two very similar terminals, one (the variant) can be defined as being just like the other (thebase) with certain exceptions. In the definition of the variant, the string capability use can be given withthe name of the base terminal:· The capabilities given before use override those in the base type named by use.· If there are multiple use capabilities, they are merged in reverse order. That is, the rightmost use ref‐erence is processed first, then the one to its left, and so forth.· Capabilities given explicitly in the entry override those brought in by use references.A capability can be canceled by placing xx@ to the left of the use reference that imports it, where xx is thecapability. For example, the entry2621-nl, smkx@, rmkx@, use=2621,defines a 2621-nl that does not have the smkx or rmkx capabilities, and hence does not turn on the functionkey labels when in visual mode. This is useful for different modes for a terminal, or for different userpreferences.An entry included via use can contain canceled capabilities, which have the same effect as if those cancelswere inline in the using terminal entry.Predefined CapabilitiesThe following is a complete table of the capabilities included in a terminfo description block and availableto terminfo-using code. In each line of the table,The variable is the name by which the programmer (at the terminfo level) accesses the capability.The capname is the short name used in the text of the database, and is used by a person updating the database.Whenever possible, capnames are chosen to be the same as or similar to the ANSI X3.64-1979 standard (nowsuperseded by ECMA-48, which uses identical or very similar names). Semantics are also intended to matchthose of the specification.The termcap code is the old termcap capability name (some capabilities are new, and have names which termcapdid not originate).Capability names have no hard length limit, but an informal limit of 5 characters has been adopted to keepthem short and to allow the tabs in the source file Caps to line up nicely.Finally, the description field attempts to convey the semantics of the capability. You may find some codes inthe description field:(P) indicates that padding may be specified#[1-9] in the description field indicates that the string is passed through tparm with parms as given (#i).(P*) indicates that padding may vary in proportion to the number of lines affected(#i) indicates the ith parameter.These are the boolean capabilities:Variable Cap- TCap DescriptionBooleans name Codeauto_left_margin bw bw cub1 wraps from col‐umn 0 to last columnauto_right_margin am am terminal has auto‐matic marginsback_color_erase bce ut screen erased withbackground colorcan_change ccc cc terminal can re-define existing col‐orsceol_standout_glitch xhp xs standout not erasedby overwriting (hp)col_addr_glitch xhpa YA only positive motionfor hpa/mhpa capscpi_changes_res cpix YF changing characterpitch changes reso‐lutioncr_cancels_micro_mode crxm YB using cr turns offmicro modedest_tabs_magic_smso xt xt tabs destructive,magic so char(t1061)eat_newline_glitch xenl xn newline ignoredafter 80 cols (con‐cept)erase_overstrike eo eo can erase over‐strikes with a blankgeneric_type gn gn generic line typehard_copy hc hc hardcopy terminalhard_cursor chts HC cursor is hard toseehas_meta_key km km Has a meta key(i.e., sets 8th-bit)has_print_wheel daisy YC printer needs opera‐tor to change char‐acter sethas_status_line hs hs has extra statuslinehue_lightness_saturation hls hl terminal uses onlyHLS color notation(Tektronix)insert_null_glitch in in insert mode distin‐guishes nullslpi_changes_res lpix YG changing line pitchchanges resolutionmemory_above da da display may beretained above thescreenmemory_below db db display may beretained below thescreenmove_insert_mode mir mi safe to move whilein insert modemove_standout_mode msgr ms safe to move whilein standout modeneeds_xon_xoff nxon nx padding will notwork, xon/xoffrequiredno_esc_ctlc xsb xb beehive (f1=escape,f2=ctrl C)no_pad_char npc NP pad character doesnot existnon_dest_scroll_region ndscr ND scrolling region isnon-destructivenon_rev_rmcup nrrmc NR smcup does notreverse rmcupover_strike os os terminal can over‐strikeprtr_silent mc5i 5i printer will notecho on screenrow_addr_glitch xvpa YD only positive motionfor vpa/mvpa capssemi_auto_right_margin sam YE printing in lastcolumn causes crstatus_line_esc_ok eslok es escape can be usedon the status linetilde_glitch hz hz cannot print ~'s(Hazeltine)transparent_underline ul ul underline characteroverstrikesxon_xoff xon xo terminal usesxon/xoff handshakingThese are the numeric capabilities:Variable Cap- TCap DescriptionNumeric name Codecolumns cols co number of columns ina lineinit_tabs it it tabs initially every# spaceslabel_height lh lh rows in each labellabel_width lw lw columns in eachlabellines lines li number of lines onscreen or pagelines_of_memory lm lm lines of memory if >line. 0 means variesmagic_cookie_glitch xmc sg number of blankcharacters left bysmso or rmsomax_attributes ma ma maximum combinedattributes terminalcan handlemax_colors colors Co maximum number ofcolors on screenmax_pairs pairs pa maximum number ofcolor-pairs on thescreenmaximum_windows wnum MW maximum number ofdefinable windowsno_color_video ncv NC video attributesthat cannot be usedwith colorsnum_labels nlab Nl number of labels onscreenpadding_baud_rate pb pb lowest baud ratewhere padding neededvirtual_terminal vt vt virtual terminalnumber (CB/unix)width_status_line wsl ws number of columns instatus lineThe following numeric capabilities are present in the SVr4.0 term structure, but are not yet documented in theman page. They came in with SVr4's printer support.Variable Cap- TCap DescriptionNumeric name Codebit_image_entwining bitwin Yo number of passes foreach bit-image rowbit_image_type bitype Yp type of bit-imagedevicebuffer_capacity bufsz Ya numbers of bytesbuffered beforeprintingbuttons btns BT number of buttons onmousedot_horz_spacing spinh Yc spacing of dots hor‐izontally in dotsper inchdot_vert_spacing spinv Yb spacing of pins ver‐tically in pins perinchmax_micro_address maddr Yd maximum value inmicro_..._addressmax_micro_jump mjump Ye maximum value inparm_..._micromicro_col_size mcs Yf character step sizewhen in micro modemicro_line_size mls Yg line step size whenin micro modenumber_of_pins npins Yh numbers of pins inprint-headoutput_res_char orc Yi horizontal resolu‐tion in units perlineoutput_res_horz_inch orhi Yk horizontal resolu‐tion in units perinchoutput_res_line orl Yj vertical resolutionin units per lineoutput_res_vert_inch orvi Yl vertical resolutionin units per inchprint_rate cps Ym print rate in char‐acters per secondwide_char_size widcs Yn character step sizewhen in double widemodeThese are the string capabilities:Variable Cap- TCap DescriptionString name Codeacs_chars acsc ac graphics charsetpairs, based onvt100back_tab cbt bt back tab (P)bell bel bl audible signal(bell) (P)carriage_return cr cr carriage return (P*)(P*)change_char_pitch cpi ZA Change number ofcharacters per inchto #1change_line_pitch lpi ZB Change number oflines per inch to #1change_res_horz chr ZC Change horizontalresolution to #1change_res_vert cvr ZD Change vertical res‐olution to #1change_scroll_region csr cs change region toline #1 to line #2(P)char_padding rmp rP like ip but when ininsert modeclear_all_tabs tbc ct clear all tab stops(P)clear_margins mgc MC clear right and leftsoft marginsclear_screen clear cl clear screen andhome cursor (P*)clr_bol el1 cb Clear to beginningof lineclr_eol el ce clear to end of line(P)clr_eos ed cd clear to end ofscreen (P*)column_address hpa ch horizontal position#1, absolute (P)command_character cmdch CC terminal settablecmd character inprototype !?create_window cwin CW define a window #1from #2,#3 to #4,#5cursor_address cup cm move to row #1 col‐umns #2cursor_down cud1 do down one linecursor_home home ho home cursor (if nocup)cursor_invisible civis vi make cursor invisi‐blecursor_left cub1 le move left one spacecursor_mem_address mrcup CM memory relative cur‐sor addressing, moveto row #1 columns #2cursor_normal cnorm ve make cursor appearnormal (undocivis/cvvis)cursor_right cuf1 nd non-destructivespace (move rightone space)cursor_to_ll ll ll last line, firstcolumn (if no cup)cursor_up cuu1 up up one linecursor_visible cvvis vs make cursor veryvisibledefine_char defc ZE Define a character#1, #2 dots wide,descender #3delete_character dch1 dc delete character(P*)delete_line dl1 dl delete line (P*)dial_phone dial DI dial number #1dis_status_line dsl ds disable status linedisplay_clock dclk DK display clockdown_half_line hd hd half a line downena_acs enacs eA enable alternatechar setenter_alt_charset_mode smacs as start alternatecharacter set (P)enter_am_mode smam SA turn on automaticmarginsenter_blink_mode blink mb turn on blinkingenter_bold_mode bold md turn on bold (extrabright) modeenter_ca_mode smcup ti string to start pro‐grams using cupenter_delete_mode smdc dm enter delete modeenter_dim_mode dim mh turn on half-brightmodeenter_doublewide_mode swidm ZF Enter double-widemodeenter_draft_quality sdrfq ZG Enter draft-qualitymodeenter_insert_mode smir im enter insert modeenter_italics_mode sitm ZH Enter italic modeenter_leftward_mode slm ZI Start leftward car‐riage motionenter_micro_mode smicm ZJ Start micro-motionmodeenter_near_letter_quality snlq ZK Enter NLQ modeenter_normal_quality snrmq ZL Enter normal-qualitymodeenter_protected_mode prot mp turn on protectedmodeenter_reverse_mode rev mr turn on reversevideo modeenter_secure_mode invis mk turn on blank mode(characters invisi‐ble)enter_shadow_mode sshm ZM Enter shadow-printmodeenter_standout_mode smso so begin standout modeenter_subscript_mode ssubm ZN Enter subscript modeenter_superscript_mode ssupm ZO Enter superscriptmodeenter_underline_mode smul us begin underline modeenter_upward_mode sum ZP Start upward car‐riage motionenter_xon_mode smxon SX turn on xon/xoffhandshakingerase_chars ech ec erase #1 characters(P)exit_alt_charset_mode rmacs ae end alternate char‐acter set (P)exit_am_mode rmam RA turn off automaticmarginsexit_attribute_mode sgr0 me turn off allattributesexit_ca_mode rmcup te strings to end pro‐grams using cupexit_delete_mode rmdc ed end delete modeexit_doublewide_mode rwidm ZQ End double-wide modeexit_insert_mode rmir ei exit insert modeexit_italics_mode ritm ZR End italic modeexit_leftward_mode rlm ZS End left-motion modeexit_micro_mode rmicm ZT End micro-motionmodeexit_shadow_mode rshm ZU End shadow-printmodeexit_standout_mode rmso se exit standout modeexit_subscript_mode rsubm ZV End subscript modeexit_superscript_mode rsupm ZW End superscript modeexit_underline_mode rmul ue exit underline modeexit_upward_mode rum ZX End reverse charac‐ter motionexit_xon_mode rmxon RX turn off xon/xoffhandshakingfixed_pause pause PA pause for 2-3 sec‐ondsflash_hook hook fh flash switch hookflash_screen flash vb visible bell (maynot move cursor)form_feed ff ff hardcopy terminalpage eject (P*)from_status_line fsl fs return from statuslinegoto_window wingo WG go to window #1hangup hup HU hang-up phoneinit_1string is1 i1 initializationstringinit_2string is2 is initializationstringinit_3string is3 i3 initializationstringinit_file if if name of initializa‐tion fileinit_prog iprog iP path name of programfor initializationinitialize_color initc Ic initialize color #1to (#2,#3,#4)initialize_pair initp Ip Initialize colorpair #1 tofg=(#2,#3,#4),bg=(#5,#6,#7)insert_character ich1 ic insert character (P)insert_line il1 al insert line (P*)insert_padding ip ip insert padding afterinserted characterkey_a1 ka1 K1 upper left of keypadkey_a3 ka3 K3 upper right of key‐padkey_b2 kb2 K2 center of keypadkey_backspace kbs kb backspace keykey_beg kbeg @1 begin keykey_btab kcbt kB back-tab keykey_c1 kc1 K4 lower left of keypadkey_c3 kc3 K5 lower right of key‐padkey_cancel kcan @2 cancel keykey_catab ktbc ka clear-all-tabs keykey_clear kclr kC clear-screen orerase keykey_close kclo @3 close keykey_command kcmd @4 command keykey_copy kcpy @5 copy keykey_create kcrt @6 create keykey_ctab kctab kt clear-tab keykey_dc kdch1 kD delete-character keykey_dl kdl1 kL delete-line keykey_down kcud1 kd down-arrow keykey_eic krmir kM sent by rmir or smirin insert modekey_end kend @7 end keykey_enter kent @8 enter/send keykey_eol kel kE clear-to-end-of-linekeykey_eos ked kS clear-to-end-of-screen keykey_exit kext @9 exit keykey_f0 kf0 k0 F0 function keykey_f1 kf1 k1 F1 function keykey_f10 kf10 k; F10 function keykey_f11 kf11 F1 F11 function keykey_f12 kf12 F2 F12 function keykey_f13 kf13 F3 F13 function keykey_f14 kf14 F4 F14 function keykey_f15 kf15 F5 F15 function keykey_f16 kf16 F6 F16 function keykey_f17 kf17 F7 F17 function keykey_f18 kf18 F8 F18 function keykey_f19 kf19 F9 F19 function keykey_f2 kf2 k2 F2 function keykey_f20 kf20 FA F20 function keykey_f21 kf21 FB F21 function keykey_f22 kf22 FC F22 function keykey_f23 kf23 FD F23 function keykey_f24 kf24 FE F24 function keykey_f25 kf25 FF F25 function keykey_f26 kf26 FG F26 function keykey_f27 kf27 FH F27 function keykey_f28 kf28 FI F28 function keykey_f29 kf29 FJ F29 function keykey_f3 kf3 k3 F3 function keykey_f30 kf30 FK F30 function keykey_f31 kf31 FL F31 function keykey_f32 kf32 FM F32 function keykey_f33 kf33 FN F33 function keykey_f34 kf34 FO F34 function keykey_f35 kf35 FP F35 function keykey_f36 kf36 FQ F36 function keykey_f37 kf37 FR F37 function keykey_f38 kf38 FS F38 function keykey_f39 kf39 FT F39 function keykey_f4 kf4 k4 F4 function keykey_f40 kf40 FU F40 function keykey_f41 kf41 FV F41 function keykey_f42 kf42 FW F42 function keykey_f43 kf43 FX F43 function keykey_f44 kf44 FY F44 function keykey_f45 kf45 FZ F45 function keykey_f46 kf46 Fa F46 function keykey_f47 kf47 Fb F47 function keykey_f48 kf48 Fc F48 function keykey_f49 kf49 Fd F49 function keykey_f5 kf5 k5 F5 function keykey_f50 kf50 Fe F50 function keykey_f51 kf51 Ff F51 function keykey_f52 kf52 Fg F52 function keykey_f53 kf53 Fh F53 function keykey_f54 kf54 Fi F54 function keykey_f55 kf55 Fj F55 function keykey_f56 kf56 Fk F56 function keykey_f57 kf57 Fl F57 function keykey_f58 kf58 Fm F58 function keykey_f59 kf59 Fn F59 function keykey_f6 kf6 k6 F6 function keykey_f60 kf60 Fo F60 function keykey_f61 kf61 Fp F61 function keykey_f62 kf62 Fq F62 function keykey_f63 kf63 Fr F63 function keykey_f7 kf7 k7 F7 function keykey_f8 kf8 k8 F8 function keykey_f9 kf9 k9 F9 function keykey_find kfnd @0 find keykey_help khlp %1 help keykey_home khome kh home keykey_ic kich1 kI insert-character keykey_il kil1 kA insert-line keykey_left kcub1 kl left-arrow keykey_ll kll kH lower-left key (homedown)key_mark kmrk %2 mark keykey_message kmsg %3 message keykey_move kmov %4 move keykey_next knxt %5 next keykey_npage knp kN next-page keykey_open kopn %6 open keykey_options kopt %7 options keykey_ppage kpp kP previous-page keykey_previous kprv %8 previous keykey_print kprt %9 print keykey_redo krdo %0 redo keykey_reference kref &1 reference keykey_refresh krfr &2 refresh keykey_replace krpl &3 replace keykey_restart krst &4 restart keykey_resume kres &5 resume keykey_right kcuf1 kr right-arrow keykey_save ksav &6 save keykey_sbeg kBEG &9 shifted begin keykey_scancel kCAN &0 shifted cancel keykey_scommand kCMD *1 shifted command keykey_scopy kCPY *2 shifted copy keykey_screate kCRT *3 shifted create keykey_sdc kDC *4 shifted delete-char‐acter keykey_sdl kDL *5 shifted delete-linekeykey_select kslt *6 select keykey_send kEND *7 shifted end keykey_seol kEOL *8 shifted clear-to-end-of-line keykey_sexit kEXT *9 shifted exit keykey_sf kind kF scroll-forward keykey_sfind kFND *0 shifted find keykey_shelp kHLP #1 shifted help keykey_shome kHOM #2 shifted home keykey_sic kIC #3 shifted insert-char‐acter keykey_sleft kLFT #4 shifted left-arrowkeykey_smessage kMSG %a shifted message keykey_smove kMOV %b shifted move keykey_snext kNXT %c shifted next keykey_soptions kOPT %d shifted options keykey_sprevious kPRV %e shifted previous keykey_sprint kPRT %f shifted print keykey_sr kri kR scroll-backward keykey_sredo kRDO %g shifted redo keykey_sreplace kRPL %h shifted replace keykey_sright kRIT %i shifted right-arrowkeykey_srsume kRES %j shifted resume keykey_ssave kSAV !1 shifted save keykey_ssuspend kSPD !2 shifted suspend keykey_stab khts kT set-tab keykey_sundo kUND !3 shifted undo keykey_suspend kspd &7 suspend keykey_undo kund &8 undo keykey_up kcuu1 ku up-arrow keykeypad_local rmkx ke leave 'key‐board_transmit' modekeypad_xmit smkx ks enter 'key‐board_transmit' modelab_f0 lf0 l0 label on functionkey f0 if not f0lab_f1 lf1 l1 label on functionkey f1 if not f1lab_f10 lf10 la label on functionkey f10 if not f10lab_f2 lf2 l2 label on functionkey f2 if not f2lab_f3 lf3 l3 label on functionkey f3 if not f3lab_f4 lf4 l4 label on functionkey f4 if not f4lab_f5 lf5 l5 label on functionkey f5 if not f5lab_f6 lf6 l6 label on functionkey f6 if not f6lab_f7 lf7 l7 label on functionkey f7 if not f7lab_f8 lf8 l8 label on functionkey f8 if not f8lab_f9 lf9 l9 label on functionkey f9 if not f9label_format fln Lf label formatlabel_off rmln LF turn off soft labelslabel_on smln LO turn on soft labelsmeta_off rmm mo turn off meta modemeta_on smm mm turn on meta mode(8th-bit on)micro_column_address mhpa ZY Like column_addressin micro modemicro_down mcud1 ZZ Like cursor_down inmicro modemicro_left mcub1 Za Like cursor_left inmicro modemicro_right mcuf1 Zb Like cursor_right inmicro modemicro_row_address mvpa Zc Like row_address #1in micro modemicro_up mcuu1 Zd Like cursor_up inmicro modenewline nel nw newline (behave likecr followed by lf)order_of_pins porder Ze Match software bitsto print-head pinsorig_colors oc oc Set all color pairsto the original onesorig_pair op op Set default pair toits original valuepad_char pad pc padding char(instead of null)parm_dch dch DC delete #1 characters(P*)parm_delete_line dl DL delete #1 lines (P*)parm_down_cursor cud DO down #1 lines (P*)parm_down_micro mcud Zf Like parm_down_cur‐sor in micro modeparm_ich ich IC insert #1 characters(P*)parm_index indn SF scroll forward #1lines (P)parm_insert_line il AL insert #1 lines (P*)parm_left_cursor cub LE move #1 charactersto the left (P)parm_left_micro mcub Zg Like parm_left_cur‐sor in micro modeparm_right_cursor cuf RI move #1 charactersto the right (P*)parm_right_micro mcuf Zh Like parm_right_cur‐sor in micro modeparm_rindex rin SR scroll back #1 lines(P)parm_up_cursor cuu UP up #1 lines (P*)parm_up_micro mcuu Zi Like parm_up_cursorin micro modepkey_key pfkey pk program function key#1 to type string #2pkey_local pfloc pl program function key#1 to execute string#2pkey_xmit pfx px program function key#1 to transmitstring #2plab_norm pln pn program label #1 toshow string #2print_screen mc0 ps print contents ofscreenprtr_non mc5p pO turn on printer for#1 bytesprtr_off mc4 pf turn off printerprtr_on mc5 po turn on printerpulse pulse PU select pulse dialingquick_dial qdial QD dial number #1 with‐out checkingremove_clock rmclk RC remove clockrepeat_char rep rp repeat char #1 #2times (P*)req_for_input rfi RF send next input char(for ptys)reset_1string rs1 r1 reset stringreset_2string rs2 r2 reset stringreset_3string rs3 r3 reset stringreset_file rf rf name of reset filerestore_cursor rc rc restore cursor toposition of lastsave_cursorrow_address vpa cv vertical position #1absolute (P)save_cursor sc sc save current cursorposition (P)scroll_forward ind sf scroll text up (P)scroll_reverse ri sr scroll text down (P)select_char_set scs Zj Select characterset, #1set_attributes sgr sa define videoattributes #1-#9(PG9)set_background setb Sb Set background color#1set_bottom_margin smgb Zk Set bottom margin atcurrent lineset_bottom_margin_parm smgbp Zl Set bottom margin atline #1 or (if smgtpis not given) #2lines from bottomset_clock sclk SC set clock, #1 hrs #2mins #3 secsset_color_pair scp sp Set current colorpair to #1set_foreground setf Sf Set foreground color#1set_left_margin smgl ML set left soft marginat current col‐umn. Seesmgl. (ML is not inBSD termcap).set_left_margin_parm smglp Zm Set left (right)margin at column #1set_right_margin smgr MR set right soft mar‐gin at current col‐umnset_right_margin_parm smgrp Zn Set right margin atcolumn #1set_tab hts st set a tab in everyrow, current columnsset_top_margin smgt Zo Set top margin atcurrent lineset_top_margin_parm smgtp Zp Set top (bottom)margin at row #1set_window wind wi current window islines #1-#2 cols#3-#4start_bit_image sbim Zq Start printing bitimage graphicsstart_char_set_def scsd Zr Start character setdefinition #1, with#2 characters in thesetstop_bit_image rbim Zs Stop printing bitimage graphicsstop_char_set_def rcsd Zt End definition ofcharacter set #1subscript_characters subcs Zu List of subscript‐able characterssuperscript_characters supcs Zv List of superscript‐able characterstab ht ta tab to next 8-spacehardware tab stopthese_cause_cr docr Zw Printing any ofthese characterscauses CRto_status_line tsl ts move to status line,column #1tone tone TO select touch tonedialingunderline_char uc uc underline char andmove past itup_half_line hu hu half a line upuser0 u0 u0 User string #0user1 u1 u1 User string #1user2 u2 u2 User string #2user3 u3 u3 User string #3user4 u4 u4 User string #4user5 u5 u5 User string #5user6 u6 u6 User string #6user7 u7 u7 User string #7user8 u8 u8 User string #8user9 u9 u9 User string #9wait_tone wait WA wait for dial-tonexoff_character xoffc XF XOFF characterxon_character xonc XN XON characterzero_motion zerom Zx No motion for subse‐quent characterThe following string capabilities are present in the SVr4.0 term structure, but were originally not documentedin the man page.Variable Cap- TCap DescriptionString name Codealt_scancode_esc scesa S8 Alternate escapefor scancode emu‐lationbit_image_carriage_return bicr Yv Move to beginningof same rowbit_image_newline binel Zz Move to next rowof the bit imagebit_image_repeat birep Xy Repeat bit imagecell #1 #2 timeschar_set_names csnm Zy Produce #1'th itemfrom list of char‐acter set namescode_set_init csin ci Init sequence formultiple codesetscolor_names colornm Yw Give name forcolor #1define_bit_image_region defbi Yx Define rectangularbit image regiondevice_type devt dv Indicate lan‐guage/codeset sup‐portdisplay_pc_char dispc S1 Display PC charac‐ter #1end_bit_image_region endbi Yy End a bit-imageregionenter_pc_charset_mode smpch S2 Enter PC characterdisplay modeenter_scancode_mode smsc S4 Enter PC scancodemodeexit_pc_charset_mode rmpch S3 Exit PC characterdisplay modeexit_scancode_mode rmsc S5 Exit PC scancodemodeget_mouse getm Gm Curses should getbutton events,parameter #1 notdocumented.key_mouse kmous Km Mouse event hasoccurredmouse_info minfo Mi Mouse statusinformationpc_term_options pctrm S6 PC terminaloptionspkey_plab pfxl xl Program functionkey #1 to typestring #2 and showstring #3req_mouse_pos reqmp RQ Request mousepositionscancode_escape scesc S7 Escape for scan‐code emulationset0_des_seq s0ds s0 Shift to codeset 0(EUC set 0, ASCII)set1_des_seq s1ds s1 Shift to codeset 1set2_des_seq s2ds s2 Shift to codeset 2set3_des_seq s3ds s3 Shift to codeset 3set_a_background setab AB Set backgroundcolor to #1, usingANSI escapeset_a_foreground setaf AF Set foregroundcolor to #1, usingANSI escapeset_color_band setcolor Yz Change to ribboncolor #1set_lr_margin smglr ML Set both left andright margins to#1, #2. (ML isnot in BSD term‐cap).set_page_length slines YZ Set page length to#1 linesset_tb_margin smgtb MT Sets both top andbottom margins to#1, #2The XSI Curses standard added these hardcopy capabilities. They were used in some post-4.1 versions of Sys‐tem V curses, e.g., Solaris 2.5 and IRIX 6.x. Except for YI, the ncurses termcap names for them areinvented. According to the XSI Curses standard, they have no termcap names. If your compiled terminfoentries use these, they may not be binary-compatible with System V terminfo entries after SVr4.1; beware!Variable Cap- TCap DescriptionString name Codeenter_horizontal_hl_mode ehhlm Xh Enter horizontalhighlight modeenter_left_hl_mode elhlm Xl Enter left highlightmodeenter_low_hl_mode elohlm Xo Enter low highlightmodeenter_right_hl_mode erhlm Xr Enter right high‐light modeenter_top_hl_mode ethlm Xt Enter top highlightmodeenter_vertical_hl_mode evhlm Xv Enter vertical high‐light modeset_a_attributes sgr1 sA Define second set ofvideo attributes#1-#6set_pglen_inch slength YI Set page length to#1 hundredth of aninch (some implemen‐tations use sL fortermcap).User-Defined CapabilitiesThe preceding section listed the predefined capabilities. They deal with some special features for terminalsno longer (or possibly never) produced. Occasionally there are special features of newer terminals which areawkward or impossible to represent by reusing the predefined capabilities.ncurses addresses this limitation by allowing user-defined capabilities. The tic and infocmp programs providethe -x option for this purpose. When -x is set, tic treats unknown capabilities as user-defined. That is, iftic encounters a capability name which it does not recognize, it infers its type (boolean, number or string)from the syntax and makes an extended table entry for that capability. The use_extended_names(3X) functionmakes this information conditionally available to applications. The ncurses library provides the data leavingmost of the behavior to applications:· User-defined capability strings whose name begins with “k” are treated as function keys.· The types (boolean, number, string) determined by tic can be inferred by successful calls on tigetflag,etc.· If the capability name happens to be two characters, the capability is also available through the termcapinterface.While termcap is said to be extensible because it does not use a predefined set of capabilities, in practiceit has been limited to the capabilities defined by terminfo implementations. As a rule, user-defined capabil‐ities intended for use by termcap applications should be limited to booleans and numbers to avoid running pastthe 1023 byte limit assumed by termcap implementations and their applications. In particular, providingextended sets of function keys (past the 60 numbered keys and the handful of special named keys) is best doneusing the longer names available using terminfo.A Sample EntryThe following entry, describing an ANSI-standard terminal, is representative of what a terminfo entry for amodern terminal typically looks like.ansi|ansi/pc-term compatible with color,am, mc5i, mir, msgr,colors#8, cols#80, it#8, lines#24, ncv#3, pairs#64,acsc=+\020\,\021-\030.^Y0\333`\004a\261f\370g\361h\260j\331k\277l\332m\300n\305o~p\304q\304r\304s_t\303u\264v\301w\302x\263y\363z\362{\343|\330}\234~\376,bel=^G, blink=\E[5m, bold=\E[1m, cbt=\E[Z, clear=\E[H\E[J,cr=^M, cub=\E[%p1%dD, cub1=\E[D, cud=\E[%p1%dB, cud1=\E[B,cuf=\E[%p1%dC, cuf1=\E[C, cup=\E[%i%p1%d;%p2%dH,cuu=\E[%p1%dA, cuu1=\E[A, dch=\E[%p1%dP, dch1=\E[P,dl=\E[%p1%dM, dl1=\E[M, ech=\E[%p1%dX, ed=\E[J, el=\E[K,el1=\E[1K, home=\E[H, hpa=\E[%i%p1%dG, ht=\E[I, hts=\EH,ich=\E[%p1%d@, il=\E[%p1%dL, il1=\E[L, ind=^J,indn=\E[%p1%dS, invis=\E[8m, kbs=^H, kcbt=\E[Z, kcub1=\E[D,kcud1=\E[B, kcuf1=\E[C, kcuu1=\E[A, khome=\E[H, kich1=\E[L,mc4=\E[4i, mc5=\E[5i, nel=\r\E[S, op=\E[39;49m,rep=%p1%c\E[%p2%{1}%-%db, rev=\E[7m, rin=\E[%p1%dT,rmacs=\E[10m, rmpch=\E[10m, rmso=\E[m, rmul=\E[m,s0ds=\E(B, s1ds=\E)B, s2ds=\E*B, s3ds=\E+B,setab=\E[4%p1%dm, setaf=\E[3%p1%dm,sgr=\E[0;10%?%p1%t;7%;%?%p2%t;4%;%?%p3%t;7%;%?%p4%t;5%;%?%p6%t;1%;%?%p7%t;8%;%?%p9%t;11%;m,sgr0=\E[0;10m, smacs=\E[11m, smpch=\E[11m, smso=\E[7m,smul=\E[4m, tbc=\E[3g, u6=\E[%i%d;%dR, u7=\E[6n,u8=\E[?%[;0123456789]c, u9=\E[c, vpa=\E[%i%p1%dd,Entries may continue onto multiple lines by placing white space at the beginning of each line except thefirst. Comments may be included on lines beginning with “#”. Capabilities in terminfo are of three types:· Boolean capabilities which indicate that the terminal has some particular feature,· numeric capabilities giving the size of the terminal or the size of particular delays, and· string capabilities, which give a sequence which can be used to perform particular terminal operations.Types of CapabilitiesAll capabilities have names. For instance, the fact that ANSI-standard terminals have automatic margins(i.e., an automatic return and line-feed when the end of a line is reached) is indicated by the capability am.Hence the description of ansi includes am. Numeric capabilities are followed by the character “#” and then apositive value. Thus cols, which indicates the number of columns the terminal has, gives the value “80” foransi. Values for numeric capabilities may be specified in decimal, octal or hexadecimal, using the C program‐ming language conventions (e.g., 255, 0377 and 0xff or 0xFF).Finally, string valued capabilities, such as el (clear to end of line sequence) are given by the two-charactercode, an “=”, and then a string ending at the next following “,”.A number of escape sequences are provided in the string valued capabilities for easy encoding of charactersthere:· Both \E and \e map to an ESCAPE character,· ^x maps to a control-x for any appropriate x, and· the sequences\n, \l, \r, \t, \b, \f, and \sproducenewline, line-feed, return, tab, backspace, form-feed, and space,respectively.X/Open Curses does not say what “appropriate x” might be. In practice, that is a printable ASCII graphiccharacter. The special case “^?” is interpreted as DEL (127). In all other cases, the character value isAND'd with 0x1f, mapping to ASCII control codes in the range 0 through 31.Other escapes include· \^ for ^,· \\ for \,· \, for comma,· \: for :,· and \0 for null.\0 will produce \200, which does not terminate a string but behaves as a null character on most terminals,providing CS7 is specified. See stty(1).The reason for this quirk is to maintain binary compatibility of the compiled terminfo files with otherimplementations, e.g., the SVr4 systems, which document this. Compiled terminfo files use null-terminatedstrings, with no lengths. Modifying this would require a new binary format, which would not work withother implementations.Finally, characters may be given as three octal digits after a \.A delay in milliseconds may appear anywhere in a string capability, enclosed in $<..> brackets, as inel=\EK$<5>, and padding characters are supplied by tputs(3X) to provide this delay.· The delay must be a number with at most one decimal place of precision; it may be followed by suffixes “*”or “/” or both.· A “*” indicates that the padding required is proportional to the number of lines affected by the opera‐tion, and the amount given is the per-affected-unit padding required. (In the case of insert character,the factor is still the number of lines affected.)Normally, padding is advisory if the device has the xon capability; it is used for cost computation butdoes not trigger delays.· A “/” suffix indicates that the padding is mandatory and forces a delay of the given number of millisec‐onds even on devices for which xon is present to indicate flow control.Sometimes individual capabilities must be commented out. To do this, put a period before the capability name.For example, see the second ind in the example above.Fetching Compiled DescriptionsThe ncurses library searches for terminal descriptions in several places. It uses only the first descriptionfound. The library has a compiled-in list of places to search which can be overridden by environment vari‐ables. Before starting to search, ncurses eliminates duplicates in its search list.· If the environment variable TERMINFO is set, it is interpreted as the pathname of a directory containingthe compiled description you are working on. Only that directory is searched.· If TERMINFO is not set, ncurses will instead look in the directory $HOME/.terminfo for a compiled descrip‐tion.· Next, if the environment variable TERMINFO_DIRS is set, ncurses will interpret the contents of that vari‐able as a list of colon-separated directories (or database files) to be searched.An empty directory name (i.e., if the variable begins or ends with a colon, or contains adjacent colons)is interpreted as the system location /etc/terminfo.· Finally, ncurses searches these compiled-in locations:· a list of directories (no default value), and· the system terminfo directory, /etc/terminfo (the compiled-in default).Preparing DescriptionsWe now outline how to prepare descriptions of terminals. The most effective way to prepare a terminaldescription is by imitating the description of a similar terminal in terminfo and to build up a descriptiongradually, using partial descriptions with vi or some other screen-oriented program to check that they arecorrect. Be aware that a very unusual terminal may expose deficiencies in the ability of the terminfo file todescribe it or bugs in the screen-handling code of the test program.To get the padding for insert line right (if the terminal manufacturer did not document it) a severe test isto edit a large file at 9600 baud, delete 16 or so lines from the middle of the screen, then hit the “u” keyseveral times quickly. If the terminal messes up, more padding is usually needed. A similar test can be usedfor insert character.Basic CapabilitiesThe number of columns on each line for the terminal is given by the cols numeric capability. If the terminalis a CRT, then the number of lines on the screen is given by the lines capability. If the terminal wrapsaround to the beginning of the next line when it reaches the right margin, then it should have the am capabil‐ity. If the terminal can clear its screen, leaving the cursor in the home position, then this is given by theclear string capability. If the terminal overstrikes (rather than clearing a position when a character isstruck over) then it should have the os capability. If the terminal is a printing terminal, with no soft copyunit, give it both hc and os. (os applies to storage scope terminals, such as TEKTRONIX 4010 series, as wellas hard copy and APL terminals.) If there is a code to move the cursor to the left edge of the current row,give this as cr. (Normally this will be carriage return, control M.) If there is a code to produce an audi‐ble signal (bell, beep, etc) give this as bel.If there is a code to move the cursor one position to the left (such as backspace) that capability should begiven as cub1. Similarly, codes to move to the right, up, and down should be given as cuf1, cuu1, and cud1.These local cursor motions should not alter the text they pass over, for example, you would not normally use“cuf1= ” because the space would erase the character moved over.A very important point here is that the local cursor motions encoded in terminfo are undefined at the left andtop edges of a CRT terminal. Programs should never attempt to backspace around the left edge, unless bw isgiven, and never attempt to go up locally off the top. In order to scroll text up, a program will go to thebottom left corner of the screen and send the ind (index) string.To scroll text down, a program goes to the top left corner of the screen and sends the ri (reverse index)string. The strings ind and ri are undefined when not on their respective corners of the screen.Parameterized versions of the scrolling sequences are indn and rin which have the same semantics as ind and riexcept that they take one parameter, and scroll that many lines. They are also undefined except at the appro‐priate edge of the screen.The am capability tells whether the cursor sticks at the right edge of the screen when text is output, butthis does not necessarily apply to a cuf1 from the last column. The only local motion which is defined fromthe left edge is if bw is given, then a cub1 from the left edge will move to the right edge of the previousrow. If bw is not given, the effect is undefined. This is useful for drawing a box around the edge of thescreen, for example. If the terminal has switch selectable automatic margins, the terminfo file usuallyassumes that this is on; i.e., am. If the terminal has a command which moves to the first column of the nextline, that command can be given as nel (newline). It does not matter if the command clears the remainder ofthe current line, so if the terminal has no cr and lf it may still be possible to craft a working nel out ofone or both of them.These capabilities suffice to describe hard-copy and “glass-tty” terminals. Thus the model 33 teletype isdescribed as33|tty33|tty|model 33 teletype,bel=^G, cols#72, cr=^M, cud1=^J, hc, ind=^J, os,while the Lear Siegler ADM-3 is described asadm3|3|lsi adm3,am, bel=^G, clear=^Z, cols#80, cr=^M, cub1=^H, cud1=^J,ind=^J, lines#24,Parameterized StringsCursor addressing and other strings requiring parameters in the terminal are described by a parameterizedstring capability, with printf-like escapes such as %x in it. For example, to address the cursor, the cupcapability is given, using two parameters: the row and column to address to. (Rows and columns are numberedfrom zero and refer to the physical screen visible to the user, not to any unseen memory.) If the terminalhas memory relative cursor addressing, that can be indicated by mrcup.The parameter mechanism uses a stack and special % codes to manipulate it. Typically a sequence will push oneof the parameters onto the stack and then print it in some format. Print (e.g., "%d") is a special case.Other operations, including "%t" pop their operand from the stack. It is noted that more complex operationsare often necessary, e.g., in the sgr string.The % encodings have the following meanings:%% outputs “%”%[[:]flags][width[.precision]][doxXs]as in printf, flags are [-+#] and space. Use a “:” to allow the next character to be a “-” flag, avoid‐ing interpreting "%-" as an operator.%c print pop() like %c in printf%s print pop() like %s in printf%p[1-9]push i'th parameter%P[a-z]set dynamic variable [a-z] to pop()%g[a-z]/get dynamic variable [a-z] and push it%P[A-Z]set static variable [a-z] to pop()%g[A-Z]get static variable [a-z] and push itThe terms "static" and "dynamic" are misleading. Historically, these are simply two different sets ofvariables, whose values are not reset between calls to tparm(3X). However, that fact is not documentedin other implementations. Relying on it will adversely impact portability to other implementations.%'c' char constant c%{nn}integer constant nn%l push strlen(pop)%+, %-, %*, %/, %marithmetic (%m is mod): push(pop() op pop())%&, %|, %^bit operations (AND, OR and exclusive-OR): push(pop() op pop())%=, %>, %<logical operations: push(pop() op pop())%A, %Ological AND and OR operations (for conditionals)%!, %~unary operations (logical and bit complement): push(op pop())%i add 1 to first two parameters (for ANSI terminals)%? expr %t thenpart %e elsepart %;This forms an if-then-else. The %e elsepart is optional. Usually the %? expr part pushes a value ontothe stack, and %t pops it from the stack, testing if it is nonzero (true). If it is zero (false), con‐trol passes to the %e (else) part.It is possible to form else-if's a la Algol 68:%? c1 %t b1 %e c2 %t b2 %e c3 %t b3 %e c4 %t b4 %e %;where ci are conditions, bi are bodies.Use the -f option of tic or infocmp to see the structure of if-then-else's. Some strings, e.g., sgr canbe very complicated when written on one line. The -f option splits the string into lines with the partsindented.Binary operations are in postfix form with the operands in the usual order. That is, to get x-5 one would use"%gx%{5}%-". %P and %g variables are persistent across escape-string evaluations.Consider the HP2645, which, to get to row 3 and column 12, needs to be sent \E&a12c03Y padded for 6 millisec‐onds. Note that the order of the rows and columns is inverted here, and that the row and column are printedas two digits. Thus its cup capability is “cup=6\E&%p2%2dc%p1%2dY”.The Microterm ACT-IV needs the current row and column sent preceded by a ^T, with the row and column simplyencoded in binary, “cup=^T%p1%c%p2%c”. Terminals which use “%c” need to be able to backspace the cursor(cub1), and to move the cursor up one line on the screen (cuu1). This is necessary because it is not alwayssafe to transmit \n ^D and \r, as the system may change or discard them. (The library routines dealing withterminfo set tty modes so that tabs are never expanded, so \t is safe to send. This turns out to be essentialfor the Ann Arbor 4080.)A final example is the LSI ADM-3a, which uses row and column offset by a blank character, thus “cup=\E=%p1%''%+%c%p2%' '%+%c”. After sending “\E=”, this pushes the first parameter, pushes the ASCII value for a space(32), adds them (pushing the sum on the stack in place of the two previous values) and outputs that value as acharacter. Then the same is done for the second parameter. More complex arithmetic is possible using thestack.Cursor MotionsIf the terminal has a fast way to home the cursor (to very upper left corner of screen) then this can be givenas home; similarly a fast way of getting to the lower left-hand corner can be given as ll; this may involvegoing up with cuu1 from the home position, but a program should never do this itself (unless ll does) becauseit can make no assumption about the effect of moving up from the home position. Note that the home positionis the same as addressing to (0,0): to the top left corner of the screen, not of memory. (Thus, the \EHsequence on HP terminals cannot be used for home.)If the terminal has row or column absolute cursor addressing, these can be given as single parameter capabili‐ties hpa (horizontal position absolute) and vpa (vertical position absolute). Sometimes these are shorterthan the more general two parameter sequence (as with the hp2645) and can be used in preference to cup. Ifthere are parameterized local motions (e.g., move n spaces to the right) these can be given as cud, cub, cuf,and cuu with a single parameter indicating how many spaces to move. These are primarily useful if the termi‐nal does not have cup, such as the TEKTRONIX 4025.If the terminal needs to be in a special mode when running a program that uses these capabilities, the codesto enter and exit this mode can be given as smcup and rmcup. This arises, for example, from terminals likethe Concept with more than one page of memory. If the terminal has only memory relative cursor addressing andnot screen relative cursor addressing, a one screen-sized window must be fixed into the terminal for cursoraddressing to work properly. This is also used for the TEKTRONIX 4025, where smcup sets the command characterto be the one used by terminfo. If the smcup sequence will not restore the screen after an rmcup sequence isoutput (to the state prior to outputting rmcup), specify nrrmc.Area ClearsIf the terminal can clear from the current position to the end of the line, leaving the cursor where it is,this should be given as el. If the terminal can clear from the beginning of the line to the current positioninclusive, leaving the cursor where it is, this should be given as el1. If the terminal can clear from thecurrent position to the end of the display, then this should be given as ed. Ed is only defined from thefirst column of a line. (Thus, it can be simulated by a request to delete a large number of lines, if a trueed is not available.)Insert/delete line and vertical motionsIf the terminal can open a new blank line before the line where the cursor is, this should be given as il1;this is done only from the first position of a line. The cursor must then appear on the newly blank line. Ifthe terminal can delete the line which the cursor is on, then this should be given as dl1; this is done onlyfrom the first position on the line to be deleted. Versions of il1 and dl1 which take a single parameter andinsert or delete that many lines can be given as il and dl.If the terminal has a settable scrolling region (like the vt100) the command to set this can be described withthe csr capability, which takes two parameters: the top and bottom lines of the scrolling region. The cursorposition is, alas, undefined after using this command.It is possible to get the effect of insert or delete line using csr on a properly chosen region; the sc and rc(save and restore cursor) commands may be useful for ensuring that your synthesized insert/delete string doesnot move the cursor. (Note that the ncurses(3NCURSES) library does this synthesis automatically, so you neednot compose insert/delete strings for an entry with csr).Yet another way to construct insert and delete might be to use a combination of index with the memory-lockfeature found on some terminals (like the HP-700/90 series, which however also has insert/delete).Inserting lines at the top or bottom of the screen can also be done using ri or ind on many terminals withouta true insert/delete line, and is often faster even on terminals with those features.The boolean non_dest_scroll_region should be set if each scrolling window is effectively a view port on ascreen-sized canvas. To test for this capability, create a scrolling region in the middle of the screen,write something to the bottom line, move the cursor to the top of the region, and do ri followed by dl1 orind. If the data scrolled off the bottom of the region by the ri re-appears, then scrolling is non-destruc‐tive. System V and XSI Curses expect that ind, ri, indn, and rin will simulate destructive scrolling; theirdocumentation cautions you not to define csr unless this is true. This curses implementation is more liberaland will do explicit erases after scrolling if ndsrc is defined.If the terminal has the ability to define a window as part of memory, which all commands affect, it should begiven as the parameterized string wind. The four parameters are the starting and ending lines in memory andthe starting and ending columns in memory, in that order.If the terminal can retain display memory above, then the da capability should be given; if display memory canbe retained below, then db should be given. These indicate that deleting a line or scrolling may bring non-blank lines up from below or that scrolling back with ri may bring down non-blank lines.Insert/Delete CharacterThere are two basic kinds of intelligent terminals with respect to insert/delete character which can bedescribed using terminfo. The most common insert/delete character operations affect only the characters onthe current line and shift characters off the end of the line rigidly. Other terminals, such as the Concept100 and the Perkin Elmer Owl, make a distinction between typed and untyped blanks on the screen, shifting uponan insert or delete only to an untyped blank on the screen which is either eliminated, or expanded to twountyped blanks.You can determine the kind of terminal you have by clearing the screen and then typing text separated by cur‐sor motions. Type “abc def” using local cursor motions (not spaces) between the “abc” and the “def”. Thenposition the cursor before the “abc” and put the terminal in insert mode. If typing characters causes therest of the line to shift rigidly and characters to fall off the end, then your terminal does not distinguishbetween blanks and untyped positions. If the “abc” shifts over to the “def” which then move together aroundthe end of the current line and onto the next as you insert, you have the second type of terminal, and shouldgive the capability in, which stands for “insert null”.While these are two logically separate attributes (one line versus multi-line insert mode, and special treat‐ment of untyped spaces) we have seen no terminals whose insert mode cannot be described with the singleattribute.Terminfo can describe both terminals which have an insert mode, and terminals which send a simple sequence toopen a blank position on the current line. Give as smir the sequence to get into insert mode. Give as rmirthe sequence to leave insert mode. Now give as ich1 any sequence needed to be sent just before sending thecharacter to be inserted. Most terminals with a true insert mode will not give ich1; terminals which send asequence to open a screen position should give it here.If your terminal has both, insert mode is usually preferable to ich1. Technically, you should not give bothunless the terminal actually requires both to be used in combination. Accordingly, some non-curses applica‐tions get confused if both are present; the symptom is doubled characters in an update using insert. Thisrequirement is now rare; most ich sequences do not require previous smir, and most smir insert modes do notrequire ich1 before each character. Therefore, the new curses actually assumes this is the case and useseither rmir/smir or ich/ich1 as appropriate (but not both). If you have to write an entry to be used undernew curses for a terminal old enough to need both, include the rmir/smir sequences in ich1.If post insert padding is needed, give this as a number of milliseconds in ip (a string option). Any othersequence which may need to be sent after an insert of a single character may also be given in ip. If yourterminal needs both to be placed into an “insert mode” and a special code to precede each inserted character,then both smir/rmir and ich1 can be given, and both will be used. The ich capability, with one parameter, n,will repeat the effects of ich1 n times.If padding is necessary between characters typed while not in insert mode, give this as a number of millisec‐onds padding in rmp.It is occasionally necessary to move around while in insert mode to delete characters on the same line (e.g.,if there is a tab after the insertion position). If your terminal allows motion while in insert mode you cangive the capability mir to speed up inserting in this case. Omitting mir will affect only speed. Some termi‐nals (notably Datamedia's) must not have mir because of the way their insert mode works.Finally, you can specify dch1 to delete a single character, dch with one parameter, n, to delete n characters,and delete mode by giving smdc and rmdc to enter and exit delete mode (any mode the terminal needs to beplaced in for dch1 to work).A command to erase n characters (equivalent to outputting n blanks without moving the cursor) can be given asech with one parameter.Highlighting, Underlining, and Visible BellsIf your terminal has one or more kinds of display attributes, these can be represented in a number of differ‐ent ways. You should choose one display form as standout mode, representing a good, high contrast, easy-on-the-eyes, format for highlighting error messages and other attention getters. (If you have a choice, reversevideo plus half-bright is good, or reverse video alone.) The sequences to enter and exit standout mode aregiven as smso and rmso, respectively. If the code to change into or out of standout mode leaves one or eventwo blank spaces on the screen, as the TVI 912 and Teleray 1061 do, then xmc should be given to tell how manyspaces are left.Codes to begin underlining and end underlining can be given as smul and rmul respectively. If the terminalhas a code to underline the current character and move the cursor one space to the right, such as theMicroterm Mime, this can be given as uc.Other capabilities to enter various highlighting modes include blink (blinking) bold (bold or extra bright)dim (dim or half-bright) invis (blanking or invisible text) prot (protected) rev (reverse video) sgr0 (turnoff all attribute modes) smacs (enter alternate character set mode) and rmacs (exit alternate character setmode). Turning on any of these modes singly may or may not turn off other modes.If there is a sequence to set arbitrary combinations of modes, this should be given as sgr (set attributes),taking 9 parameters. Each parameter is either 0 or nonzero, as the corresponding attribute is on or off. The9 parameters are, in order: standout, underline, reverse, blink, dim, bold, blank, protect, alternate charac‐ter set. Not all modes need be supported by sgr, only those for which corresponding separate attribute com‐mands exist.For example, the DEC vt220 supports most of the modes:tparm parameter attribute escape sequencenone none \E[0mp1 standout \E[0;1;7mp2 underline \E[0;4mp3 reverse \E[0;7mp4 blink \E[0;5mp5 dim not availablep6 bold \E[0;1mp7 invis \E[0;8mp8 protect not usedp9 altcharset ^O (off) ^N (on)We begin each escape sequence by turning off any existing modes, since there is no quick way to determinewhether they are active. Standout is set up to be the combination of reverse and bold. The vt220 terminalhas a protect mode, though it is not commonly used in sgr because it protects characters on the screen fromthe host's erasures. The altcharset mode also is different in that it is either ^O or ^N, depending onwhether it is off or on. If all modes are turned on, the resulting sequence is \E[0;1;4;5;7;8m^N.Some sequences are common to different modes. For example, ;7 is output when either p1 or p3 is true, thatis, if either standout or reverse modes are turned on.Writing out the above sequences, along with their dependencies yieldssequence when to output terminfo translation\E[0 always \E[0;1 if p1 or p6 %?%p1%p6%|%t;1%;;4 if p2 %?%p2%|%t;4%;;5 if p4 %?%p4%|%t;5%;;7 if p1 or p3 %?%p1%p3%|%t;7%;;8 if p7 %?%p7%|%t;8%;m always m^N or ^O if p9 ^N, else ^O %?%p9%t^N%e^O%;Putting this all together into the sgr sequence gives:sgr=\E[0%?%p1%p6%|%t;1%;%?%p2%t;4%;%?%p4%t;5%;%?%p1%p3%|%t;7%;%?%p7%t;8%;m%?%p9%t\016%e\017%;,Remember that if you specify sgr, you must also specify sgr0. Also, some implementations rely on sgr beinggiven if sgr0 is, Not all terminfo entries necessarily have an sgr string, however. Many terminfo entries arederived from termcap entries which have no sgr string. The only drawback to adding an sgr string is thattermcap also assumes that sgr0 does not exit alternate character set mode.Terminals with the “magic cookie” glitch (xmc) deposit special “cookies” when they receive mode-settingsequences, which affect the display algorithm rather than having extra bits for each character. Some termi‐nals, such as the HP 2621, automatically leave standout mode when they move to a new line or the cursor isaddressed. Programs using standout mode should exit standout mode before moving the cursor or sending a new‐line, unless the msgr capability, asserting that it is safe to move in standout mode, is present.If the terminal has a way of flashing the screen to indicate an error quietly (a bell replacement) then thiscan be given as flash; it must not move the cursor.If the cursor needs to be made more visible than normal when it is not on the bottom line (to make, for exam‐ple, a non-blinking underline into an easier to find block or blinking underline) give this sequence as cvvis.If there is a way to make the cursor completely invisible, give that as civis. The capability cnorm should begiven which undoes the effects of both of these modes.If your terminal correctly generates underlined characters (with no special codes needed) even though it doesnot overstrike, then you should give the capability ul. If a character overstriking another leaves both char‐acters on the screen, specify the capability os. If overstrikes are erasable with a blank, then this shouldbe indicated by giving eo.Keypad and Function KeysIf 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 exam‐ple, to the unshifted HP 2621 keys). If the keypad can be set to transmit or not transmit, give these codesas smkx and rmkx. Otherwise the keypad is assumed to always transmit.The codes sent by the left arrow, right arrow, up arrow, down arrow, and home keys can be given as kcub1,kcuf1, kcuu1, kcud1, and khome respectively. If there are function keys such as f0, f1, ..., f10, the codesthey send can be given as kf0, kf1, ..., kf10. If these keys have labels other than the default f0 throughf10, the labels can be given as lf0, lf1, ..., lf10.The codes transmitted by certain other special keys can be given:· kll (home down),· kbs (backspace),· ktbc (clear all tabs),· kctab (clear the tab stop in this column),· kclr (clear screen or erase key),· kdch1 (delete character),· kdl1 (delete line),· krmir (exit insert mode),· kel (clear to end of line),· ked (clear to end of screen),· kich1 (insert character or enter insert mode),· kil1 (insert line),· knp (next page),· kpp (previous page),· kind (scroll forward/down),· kri (scroll backward/up),· khts (set a tab stop in this column).In addition, if the keypad has a 3 by 3 array of keys including the four arrow keys, the other five keys canbe given as ka1, ka3, kb2, kc1, and kc3. These keys are useful when the effects of a 3 by 3 directional padare needed.Strings to program function keys can be given as pfkey, pfloc, and pfx. A string to program screen labelsshould be specified as pln. Each of these strings takes two parameters: the function key number to program(from 0 to 10) and the string to program it with. Function key numbers out of this range may program unde‐fined keys in a terminal dependent manner. The difference between the capabilities is that pfkey causespressing the given key to be the same as the user typing the given string; pfloc causes the string to be exe‐cuted by the terminal in local; and pfx causes the string to be transmitted to the computer.The capabilities nlab, lw and lh define the number of programmable screen labels and their width and height.If there are commands to turn the labels on and off, give them in smln and rmln. smln is normally outputafter one or more pln sequences to make sure that the change becomes visible.Tabs and InitializationIf the terminal has hardware tabs, the command to advance to the next tab stop can be given as ht (usuallycontrol I). A “back-tab” command which moves leftward to the preceding tab stop can be given as cbt. By con‐vention, if the teletype modes indicate that tabs are being expanded by the computer rather than being sent tothe terminal, programs should not use ht or cbt even if they are present, since the user may not have the tabstops properly set. If the terminal has hardware tabs which are initially set every n spaces when the termi‐nal is powered up, the numeric parameter it is given, showing the number of spaces the tabs are set to. Thisis normally used by the tset command to determine whether to set the mode for hardware tab expansion, andwhether to set the tab stops. If the terminal has tab stops that can be saved in non-volatile memory, theterminfo description can assume that they are properly set.Other capabilities include is1, is2, and is3, initialization strings for the terminal, iprog, the path name ofa program to be run to initialize the terminal, and if, the name of a file containing long initializationstrings. These strings are expected to set the terminal into modes consistent with the rest of the terminfodescription. They are normally sent to the terminal, by the init option of the tput program, each time theuser logs in. They will be printed in the following order:run the programiprogoutput is1 is2set the margins usingmgc, smgl and smgrset tabs usingtbc and htsprint the fileifand finallyoutput is3.Most initialization is done with is2. Special terminal modes can be set up without duplicating strings byputting the common sequences in is2 and special cases in is1 and is3.A set of sequences that does a harder reset from a totally unknown state can be given as rs1, rs2, rf and rs3,analogous to is1 , is2 , if and is3 respectively. These strings are output by the reset program, which isused when the terminal gets into a wedged state. Commands are normally placed in rs1, rs2 rs3 and rf only ifthey produce annoying effects on the screen and are not necessary when logging in. For example, the commandto set the vt100 into 80-column mode would normally be part of is2, but it causes an annoying glitch of thescreen and is not normally needed since the terminal is usually already in 80 column mode.The reset program writes strings including iprog, etc., in the same order as the init program, using rs1,etc., instead of is1, etc. If any of rs1, rs2, rs3, or rf reset capability strings are missing, the resetprogram falls back upon the corresponding initialization capability string.If there are commands to set and clear tab stops, they can be given as tbc (clear all tab stops) and hts (seta tab stop in the current column of every row). If a more complex sequence is needed to set the tabs than canbe described by this, the sequence can be placed in is2 or if.Delays and PaddingMany older and slower terminals do not support either XON/XOFF or DTR handshaking, including hard copy termi‐nals and some very archaic CRTs (including, for example, DEC VT100s). These may require padding charactersafter certain cursor motions and screen changes.If the terminal uses xon/xoff handshaking for flow control (that is, it automatically emits ^S back to thehost when its input buffers are close to full), set xon. This capability suppresses the emission of padding.You can also set it for memory-mapped console devices effectively that do not have a speed limit. Paddinginformation should still be included so that routines can make better decisions about relative costs, butactual pad characters will not be transmitted.If pb (padding baud rate) is given, padding is suppressed at baud rates below the value of pb. If the entryhas no padding baud rate, then whether padding is emitted or not is completely controlled by xon.If the terminal requires other than a null (zero) character as a pad, then this can be given as pad. Only thefirst character of the pad string is used.Status LinesSome terminals have an extra “status line” which is not normally used by software (and thus not counted in theterminal's lines capability).The simplest case is a status line which is cursor-addressable but not part of the main scrolling region onthe screen; the Heathkit H19 has a status line of this kind, as would a 24-line VT100 with a 23-line scrollingregion set up on initialization. This situation is indicated by the hs capability.Some terminals with status lines need special sequences to access the status line. These may be expressed asa string with single parameter tsl which takes the cursor to a given zero-origin column on the status line.The capability fsl must return to the main-screen cursor positions before the last tsl. You may need to embedthe string values of sc (save cursor) and rc (restore cursor) in tsl and fsl to accomplish this.The status line is normally assumed to be the same width as the width of the terminal. If this is untrue, youcan specify it with the numeric capability wsl.A command to erase or blank the status line may be specified as dsl.The boolean capability eslok specifies that escape sequences, tabs, etc., work ordinarily in the status line.The ncurses implementation does not yet use any of these capabilities. They are documented here in case theyever become important.Line GraphicsMany terminals have alternate character sets useful for forms-drawing. Terminfo and curses have built-in sup‐port for most of the drawing characters supported by the VT100, with some characters from the AT&T 4410v1added. This alternate character set may be specified by the acsc capability.Glyph ACS Ascii acsc acscName Name Default Char Value───────────────────────────────────────────────────────────────────────────────────────────────────────────────arrow pointing right ACS_RARROW > + 0x2barrow pointing left ACS_LARROW < , 0x2carrow pointing up ACS_UARROW ^ - 0x2darrow pointing down ACS_DARROW v . 0x2esolid square block ACS_BLOCK # 0 0x30diamond ACS_DIAMOND + ` 0x60checker board (stipple) ACS_CKBOARD : a 0x61degree symbol ACS_DEGREE \ f 0x66plus/minus ACS_PLMINUS # g 0x67board of squares ACS_BOARD # h 0x68lantern symbol ACS_LANTERN # i 0x69lower right corner ACS_LRCORNER + j 0x6aupper right corner ACS_URCORNER + k 0x6bupper left corner ACS_ULCORNER + l 0x6clower left corner ACS_LLCORNER + m 0x6dlarge plus or crossover ACS_PLUS + n 0x6escan line 1 ACS_S1 ~ o 0x6fscan line 3 ACS_S3 - p 0x70horizontal line ACS_HLINE - q 0x71scan line 7 ACS_S7 - r 0x72scan line 9 ACS_S9 _ s 0x73tee pointing right ACS_LTEE + t 0x74tee pointing left ACS_RTEE + u 0x75tee pointing up ACS_BTEE + v 0x76tee pointing down ACS_TTEE + w 0x77vertical line ACS_VLINE | x 0x78less-than-or-equal-to ACS_LEQUAL < y 0x79greater-than-or-equal-to ACS_GEQUAL > z 0x7agreek pi ACS_PI * { 0x7bnot-equal ACS_NEQUAL ! | 0x7cUK pound sign ACS_STERLING f } 0x7dbullet ACS_BULLET o ~ 0x7eA few notes apply to the table itself:· X/Open Curses incorrectly states that the mapping for lantern is uppercase “I” although Unix implementa‐tions use the lowercase “i” mapping.· The DEC VT100 implemented graphics using the alternate character set feature, temporarily switching modesand sending characters in the range 0x60 (96) to 0x7e (126) (the acsc Value column in the table).· The AT&T terminal added graphics characters outside that range.Some of the characters within the range do not match the VT100; presumably they were used in the AT&T ter‐minal: board of squares replaces the VT100 newline symbol, while lantern symbol replaces the VT100 verti‐cal tab symbol. The other VT100 symbols for control characters (horizontal tab, carriage return and line-feed) are not (re)used in curses.The best way to define a new device's graphics set is to add a column to a copy of this table for your termi‐nal, giving the character which (when emitted between smacs/rmacs switches) will be rendered as the corre‐sponding graphic. Then read off the VT100/your terminal character pairs right to left in sequence; thesebecome the ACSC string.Color HandlingThe curses library functions init_pair and init_color manipulate the color pairs and color values discussed inthis section (see curs_color(3X) for details on these and related functions).Most color terminals are either “Tektronix-like” or “HP-like”:· Tektronix-like terminals have a predefined set of N colors (where N is usually 8), and can set character-cell foreground and background characters independently, mixing them into N * N color-pairs.· On HP-like terminals, the user must set each color pair up separately (foreground and background are notindependently settable). Up to M color-pairs may be set up from 2*M different colors. ANSI-compatibleterminals are Tektronix-like.Some basic color capabilities are independent of the color method. The numeric capabilities colors and pairsspecify the maximum numbers of colors and color-pairs that can be displayed simultaneously. The op (originalpair) string resets foreground and background colors to their default values for the terminal. The oc stringresets all colors or color-pairs to their default values for the terminal. Some terminals (including many PCterminal emulators) erase screen areas with the current background color rather than the power-up defaultbackground; these should have the boolean capability bce.While the curses library works with color pairs (reflecting the inability of some devices to set foregroundand background colors independently), there are separate capabilities for setting these features:· To change the current foreground or background color on a Tektronix-type terminal, use setaf (set ANSIforeground) and setab (set ANSI background) or setf (set foreground) and setb (set background). Thesetake one parameter, the color number. The SVr4 documentation describes only setaf/setab; the XPG4 draftsays that "If the terminal supports ANSI escape sequences to set background and foreground, they should becoded as setaf and setab, respectively.· If the terminal supports other escape sequences to set background and foreground, they should be coded assetf and setb, respectively. The vidputs and the refresh(3X) functions use the setaf and setab capabili‐ties if they are defined.The setaf/setab and setf/setb capabilities take a single numeric argument each. Argument values 0-7 ofsetaf/setab are portably defined as follows (the middle column is the symbolic #define available in the headerfor the curses or ncurses libraries). The terminal hardware is free to map these as it likes, but the RGBvalues indicate normal locations in color space.Color #define Value RGBblack COLOR_BLACK 0 0, 0, 0red COLOR_RED 1 max,0,0green COLOR_GREEN 2 0,max,0yellow COLOR_YELLOW 3 max,max,0blue COLOR_BLUE 4 0,0,maxmagenta COLOR_MAGENTA 5 max,0,maxcyan COLOR_CYAN 6 0,max,maxwhite COLOR_WHITE 7 max,max,maxThe argument values of setf/setb historically correspond to a different mapping, i.e.,Color #define Value RGBblack COLOR_BLACK 0 0, 0, 0blue COLOR_BLUE 1 0,0,maxgreen COLOR_GREEN 2 0,max,0cyan COLOR_CYAN 3 0,max,maxred COLOR_RED 4 max,0,0magenta COLOR_MAGENTA 5 max,0,maxyellow COLOR_YELLOW 6 max,max,0white COLOR_WHITE 7 max,max,maxIt is important to not confuse the two sets of color capabilities; otherwise red/blue will be interchanged onthe display.On an HP-like terminal, use scp with a color-pair number parameter to set which color pair is current.Some terminals allow the color values to be modified:· On a Tektronix-like terminal, the capability ccc may be present to indicate that colors can be modified.If so, the initc capability will take a color number (0 to colors - 1)and three more parameters whichdescribe the color. These three parameters default to being interpreted as RGB (Red, Green, Blue) values.If the boolean capability hls is present, they are instead as HLS (Hue, Lightness, Saturation) indices.The ranges are terminal-dependent.· On an HP-like terminal, initp may give a capability for changing a color-pair value. It will take sevenparameters; a color-pair number (0 to max_pairs - 1), and two triples describing first background and thenforeground colors. These parameters must be (Red, Green, Blue) or (Hue, Lightness, Saturation) dependingon hls.On some color terminals, colors collide with highlights. You can register these collisions with the ncv capa‐bility. This is a bit-mask of attributes not to be used when colors are enabled. The correspondence with theattributes understood by curses is as follows:Attribute Bit Decimal Set byA_STANDOUT 0 1 sgrA_UNDERLINE 1 2 sgrA_REVERSE 2 4 sgrA_BLINK 3 8 sgrA_DIM 4 16 sgrA_BOLD 5 32 sgrA_INVIS 6 64 sgrA_PROTECT 7 128 sgrA_ALTCHARSET 8 256 sgrA_HORIZONTAL 9 512 sgr1A_LEFT 10 1024 sgr1A_LOW 11 2048 sgr1A_RIGHT 12 4096 sgr1A_TOP 13 8192 sgr1A_VERTICAL 14 16384 sgr1A_ITALIC 15 32768 sitmFor example, on many IBM PC consoles, the underline attribute collides with the foreground color blue and isnot available in color mode. These should have an ncv capability of 2.SVr4 curses does nothing with ncv, ncurses recognizes it and optimizes the output in favor of colors.MiscellaneousIf the terminal requires other than a null (zero) character as a pad, then this can be given as pad. Only thefirst character of the pad string is used. If the terminal does not have a pad character, specify npc. Notethat ncurses implements the termcap-compatible PC variable; though the application may set this value to some‐thing other than a null, ncurses will test npc first and use napms if the terminal has no pad character.If the terminal can move up or down half a line, this can be indicated with hu (half-line up) and hd (half-line down). This is primarily useful for superscripts and subscripts on hard-copy terminals. If a hard-copyterminal can eject to the next page (form feed), give this as ff (usually control L).If there is a command to repeat a given character a given number of times (to save time transmitting a largenumber of identical characters) this can be indicated with the parameterized string rep. The first parameteris the character to be repeated and the second is the number of times to repeat it. Thus, tparm(repeat_char,'x', 10) is the same as “xxxxxxxxxx”.If the terminal has a settable command character, such as the TEKTRONIX 4025, this can be indicated withcmdch. A prototype command character is chosen which is used in all capabilities. This character is given inthe cmdch capability to identify it. The following convention is supported on some UNIX systems: The environ‐ment is to be searched for a CC variable, and if found, all occurrences of the prototype character arereplaced with the character in the environment variable.Terminal descriptions that do not represent a specific kind of known terminal, such as switch, dialup, patch,and network, should include the gn (generic) capability so that programs can complain that they do not knowhow to talk to the terminal. (This capability does not apply to virtual terminal descriptions for which theescape sequences are known.)If the terminal has a “meta key” which acts as a shift key, setting the 8th bit of any character transmitted,this fact can be indicated with km. Otherwise, software will assume that the 8th bit is parity and it willusually be cleared. If strings exist to turn this “meta mode” on and off, they can be given as smm and rmm.If the terminal has more lines of memory than will fit on the screen at once, the number of lines of memorycan be indicated with lm. A value of lm#0 indicates that the number of lines is not fixed, but that there isstill more memory than fits on the screen.If the terminal is one of those supported by the UNIX virtual terminal protocol, the terminal number can begiven as vt.Media copy strings which control an auxiliary printer connected to the terminal can be given as mc0: print thecontents of the screen, mc4: turn off the printer, and mc5: turn on the printer. When the printer is on, alltext sent to the terminal will be sent to the printer. It is undefined whether the text is also displayed onthe terminal screen when the printer is on. A variation mc5p takes one parameter, and leaves the printer onfor as many characters as the value of the parameter, then turns the printer off. The parameter should notexceed 255. All text, including mc4, is transparently passed to the printer while an mc5p is in effect.Glitches and BraindamageHazeltine terminals, which do not allow “~” characters to be displayed should indicate hz.Terminals which ignore a line-feed immediately after an am wrap, such as the Concept and vt100, should indi‐cate xenl.If el is required to get rid of standout (instead of merely writing normal text on top of it), xhp should begiven.Teleray terminals, where tabs turn all characters moved over to blanks, should indicate xt (destructive tabs).Note: the variable indicating this is now “dest_tabs_magic_smso”; in older versions, it was teleray_glitch.This glitch is also taken to mean that it is not possible to position the cursor on top of a “magic cookie”,that to erase standout mode it is instead necessary to use delete and insert line. The ncurses implementationignores this glitch.The Beehive Superbee, which is unable to correctly transmit the escape or control C characters, has xsb, indi‐cating that the f1 key is used for escape and f2 for control C. (Only certain Superbees have this problem,depending on the ROM.) Note that in older terminfo versions, this capability was called “beehive_glitch”; itis now “no_esc_ctl_c”.Other specific terminal problems may be corrected by adding more capabilities of the form xx.Pitfalls of Long EntriesLong terminfo entries are unlikely to be a problem; to date, no entry has even approached terminfo's 4096-bytestring-table maximum. Unfortunately, the termcap translations are much more strictly limited (to 1023 bytes),thus termcap translations of long terminfo entries can cause problems.The man pages for 4.3BSD and older versions of tgetent instruct the user to allocate a 1024-byte buffer forthe termcap entry. The entry gets null-terminated by the termcap library, so that makes the maximum safelength for a termcap entry 1k-1 (1023) bytes. Depending on what the application and the termcap library beingused does, and where in the termcap file the terminal type that tgetent is searching for is, several badthings can happen.Some termcap libraries print a warning message or exit if they find an entry that's longer than 1023 bytes;others do not; others truncate the entries to 1023 bytes. Some application programs allocate more than therecommended 1K for the termcap entry; others do not.Each termcap entry has two important sizes associated with it: before "tc" expansion, and after "tc" expan‐sion. "tc" is the capability that tacks on another termcap entry to the end of the current one, to add on itscapabilities. If a termcap entry does not use the "tc" capability, then of course the two lengths are thesame.The "before tc expansion" length is the most important one, because it affects more than just users of thatparticular terminal. This is the length of the entry as it exists in /etc/termcap, minus the backslash-new‐line pairs, which tgetent strips out while reading it. Some termcap libraries strip off the final newline,too (GNU termcap does not). Now suppose:· a termcap entry before expansion is more than 1023 bytes long,· and the application has only allocated a 1k buffer,· and the termcap library (like the one in BSD/OS 1.1 and GNU) reads the whole entry into the buffer, nomatter what its length, to see if it is the entry it wants,· and tgetent is searching for a terminal type that either is the long entry, appears in the termcap fileafter the long entry, or does not appear in the file at all (so that tgetent has to search the whole term‐cap file).Then tgetent will overwrite memory, perhaps its stack, and probably core dump the program. Programs like tel‐net are particularly vulnerable; modern telnets pass along values like the terminal type automatically. Theresults are almost as undesirable with a termcap library, like SunOS 4.1.3 and Ultrix 4.4, that prints warningmessages when it reads an overly long termcap entry. If a termcap library truncates long entries, like OSF/13.0, it is immune to dying here but will return incorrect data for the terminal.The "after tc expansion" length will have a similar effect to the above, but only for people who actually setTERM to that terminal type, since tgetent only does "tc" expansion once it is found the terminal type it waslooking for, not while searching.In summary, a termcap entry that is longer than 1023 bytes can cause, on various combinations of termcaplibraries and applications, a core dump, warnings, or incorrect operation. If it is too long even before "tc"expansion, it will have this effect even for users of some other terminal types and users whose TERM variabledoes not have a termcap entry.When in -C (translate to termcap) mode, the ncurses implementation of tic(1) issues warning messages when thepre-tc length of a termcap translation is too long. The -c (check) option also checks resolved (after tcexpansion) lengths.Binary CompatibilityIt is not wise to count on portability of binary terminfo entries between commercial UNIX versions. The prob‐lem is that there are at least two versions of terminfo (under HP-UX and AIX) which diverged from System Vterminfo after SVr1, and have added extension capabilities to the string table that (in the binary format)collide with System V and XSI Curses extensions.EXTENSIONSSearching for terminal descriptions in $HOME/.terminfo and TERMINFO_DIRS is not supported by older implementa‐tions.Some SVr4 curses implementations, and all previous to SVr4, do not interpret the %A and %O operators in param‐eter strings.SVr4/XPG4 do not specify whether msgr licenses movement while in an alternate-character-set mode (such modesmay, among other things, map CR and NL to characters that do not trigger local motions). The ncurses imple‐mentation ignores msgr in ALTCHARSET mode. This raises the possibility that an XPG4 implementation making theopposite interpretation may need terminfo entries made for ncurses to have msgr turned off.The ncurses library handles insert-character and insert-character modes in a slightly non-standard way to getbetter update efficiency. See the Insert/Delete Character subsection above.The parameter substitutions for set_clock and display_clock are not documented in SVr4 or the XSI Curses stan‐dard. They are deduced from the documentation for the AT&T 505 terminal.Be careful assigning the kmous capability. The ncurses library wants to interpret it as KEY_MOUSE, for use byterminals and emulators like xterm that can return mouse-tracking information in the keyboard-input stream.X/Open Curses does not mention italics. Portable applications must assume that numeric capabilities aresigned 16-bit values. This includes the no_color_video (ncv) capability. The 32768 mask value used for ital‐ics with ncv can be confused with an absent or cancelled ncv. If italics should work with colors, then thencv value must be specified, even if it is zero.Different commercial ports of terminfo and curses support different subsets of the XSI Curses standard and (insome cases) different extension sets. Here is a summary, accurate as of October 1995:· SVR4, Solaris, ncurses -- These support all SVr4 capabilities.· SGI -- Supports the SVr4 set, adds one undocumented extended string capability (set_pglen).· SVr1, Ultrix -- These support a restricted subset of terminfo capabilities. The booleans end withxon_xoff; the numerics with width_status_line; and the strings with prtr_non.· HP/UX -- Supports the SVr1 subset, plus the SVr[234] numerics num_labels, label_height, label_width, plusfunction keys 11 through 63, plus plab_norm, label_on, and label_off, plus some incompatible extensions inthe string table.· AIX -- Supports the SVr1 subset, plus function keys 11 through 63, plus a number of incompatible stringtable extensions.· OSF -- Supports both the SVr4 set and the AIX extensions.FILES/etc/terminfo/?/* files containing terminal descriptions
terminfo -w ...