1.\" 2.\" $Id: screen.4,v 1.9 1998/03/12 07:30:37 charnier Exp $ 3.\" 4.Dd January 8, 1995 5.Dt SCREEN 4 i386 6.Os FreeBSD 7.Sh NAME 8.Nm screen 9.Nd pc display interface 10.Sh DESCRIPTION 11 12Access to the 13.Ar virtual consoles 14are obtained through the device files 15ttyv0 - ttyvb in /dev. 16Each of these files correspond to a separate 17virtual console. 18All virtual console devices can be open at once, but only one is 19active at a time. The active virtual console "owns" the keyboard and 20display screen. 21.Pp 22Output to a virtual console that not currently is on the display is 23saved in a buffer that holds a "screenfull" (normally 25) lines. 24Any output written to 25.Ar /dev/console 26(the original console device) is echoed to /dev/ttyv0. 27.Pp 28To switch between the virtual consoles one uses the sequence 29.Ar ALT+Fn 30, which means hold down ALT and press one of the function keys. The 31virtual console with the same number as the function key is then 32selected as the current virtual console, and given exclusive use of 33the keyboard and display. This switch sequence can be changed via 34the keyboard mapping ioctl call (see keyboard.4) 35.Pp 36 37The console allows entering values that are not physically 38present on the keyboard via a special keysequence. 39To use this facility press and hold down ALT, 40then enter a decimal number from 0-255 via the numerical keypad, then 41release ALT. The entered value is then used as the ASCII value for one 42character. This way it is possible to enter any ASCII value. 43The console driver also includes a history function. It is activated by 44pressing the scroll-lock key. This holds the display, and enables the cursor 45arrows for scrolling up and down through the last scrolled out lines. 46 47The console understands a subset of the ANSI x3.64 character 48sequences. For compatibility with the old pccons, the PC3 character 49sequences is also supported. 50.Pp 51.Bd -literal 52ANSI Seq Function Termcap entry 53======= ======= ===================================== ============== 54 55-- E7 Save cursor position sc 56 57-- E8 Restore saved cursor position rc 58 59CUU E[nA move cursor up n lines up/UP (ku) 60 61CUD E[nB move cursor down n lines do/DO (kd) 62 63CUF E[nC move cursor right n characters nd/RI (kr) 64 65CUB E[nD move cursor left n characters --/LE (kl) 66 67HPA E[n` move cursor to character position n ch 68 69HPR E[na move cursor right n characters -- 70 71VPA E[nd move cursor to line n cv 72 73VPR E[ne move cursor down n lines -- 74 75CPL E[nF move cursor to start of line, -- (@7) 76 n lines up 77 78CNL E[nE move cursor to start of line, nw 79 n lines down 80 81CUP E[y;xH Move cursor to x, y cm 82 83HVP E[y;xf Move cursor to x, y -- 84 85CBT E[nZ Move cursor back n tab stops bt (kB) 86 87IL E[nL Insert n blank lines al/AL 88 89ICH E[n@ Insert n blank characters ic/IC 90 91DL E[nM Delete n lines dl/DL 92 93DCH E[nP Delete n characters dc/DC 94 95ED E[nJ Erase part or all of display: cd 96 n=0 from cursor to end of display, 97 n=1 from begin of display to cursor, 98 n=2 entire display. 99 100EL E[nK Erase part or all of line: ce 101 n=0 from cursor to end of line, 102 n=1 from begin of line to cursor, 103 n=2 entire line. 104 105ECH E[nX Erase n characters ec 106 107SU E[nS Scroll display n lines up (forward) sf/SF 108 109SD E[nT Scroll display n lines down (reverse) sr/SR 110 111 112SGR E[nm Set character attributes: -- 113 n= 0 normal attribute (all off) 114 n= 1 bold (highlight) 115 n= 4 underscore (if supported by HW) 116 n= 5 blink (if supported by HW) 117 n= 7 reverse 118 n=3X set foreground color (see table) 119 n=4X set background color (see table) 120 121 X=0 black X=1 red 122 X=2 green X=3 brown 123 X=4 blue X=5 magenta 124 X=6 cyan X=7 white 125 126-- E[s Save cursor position sc 127 128-- E[u Restore saved cursor position rc 129 130-- E[=p;dB Set bell pitch (p) and duration (d), -- 131 picth is in units of 840 nS, 132 duration is units of 0,1 S. 133 134-- E[=tC Set cursor type, 1 selects a blinking -- 135 cursor, 0 a steady cursor. 136 137-- E[=nA Set the border color to color n 138 (see table) (if supported by HW) 139 140-- E[=cF set normal foreground color to n -- 141 (see table) 142 143-- E[=cG set normal background color to n -- 144 (see table) 145 146-- E[=cH set reverse foreground color to n -- 147 (see table) 148 149-- E[=cI set reverse background color to n -- 150 (see table) 151 152 n= 0 black n= 8 grey 153 n= 1 blue n= 9 light blue 154 n= 2 green n=10 light green 155 n= 3 cyan n=11 light cyan 156 n= 4 red n=12 light red 157 n= 5 magenta n=13 light magenta 158 n= 6 brown n=14 yellow 159 n= 7 white n=15 light white 160 161note: the first E in the sequences stands for ESC (0x1b) 162 163.Ed 164.Pp 165.Sh AUTHORS 166.An S�ren Schmidt Aq sos@FreeBSD.org 167