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Terminal control/Dimensions

From Rosetta Code
Task
Terminal control/Dimensions
You are encouraged to solve this task according to the task description, using any language you may know.

Determine the height and width of the terminal, and store this information into variables for subsequent use.


Applesoft BASIC[edit]

WIDTH = PEEK(33)
HEIGHT = PEEK(35) - PEEK(34)

AutoHotkey[edit]

Works with: AutoHotkey_L
Translation of: C

AutoHotkey is not built for the console (it is GUI oriented) so we must call the WinAPI directly.

DllCall( "AllocConsole" ) ; create a console if not launched from one
hConsole := DllCall( "GetStdHandle", int, STDOUT := -11 )
 
MsgBox Resize the console...
 
VarSetCapacity(csbi, 22) ; CONSOLE_SCREEN_BUFFER_INFO structure
DllCall("GetConsoleScreenBufferInfo", UPtr, hConsole, UPtr, &csbi)
Left := NumGet(csbi, 10, "short")
Top := NumGet(csbi, 12, "short")
Right := NumGet(csbi, 14, "short")
Bottom := NumGet(csbi, 16, "short")
 
columns := right - left + 1
rows := bottom - top + 1
MsgBox %columns% columns and %rows% rows

Axe[edit]

Since Axe currently only supports the TI-83/84, the home screen dimensions are fixed at 16 columns by 8 rows.

Batch File[edit]

Screen Buffer Size:

@echo off
 
for /f "tokens=1,2 delims= " %%A in ('mode con') do (
if "%%A"=="Lines:" set line=%%B
if "%%A"=="Columns:" set cols=%%B
)
 
echo Lines: %line%
echo Columns: %cols%
exit /b 0
Output:
>Size.Bat
Lines: 300
Columns: 80

>

BBC BASIC[edit]

      dx% = @[email protected]% : REM Width of text viewport in pixels
dy% = @[email protected]% : REM Height of text viewport in pixels

C[edit]

C provides no standard way to find the size of a terminal.

Library: BSD libc
[edit]

BSD systems (and some other Unix clones) have TIOCGWINSZ. This ioctl(2) call gets the "window size" of a tty(4) device.

Almost all terminal devices can do NAWS (Negotiate About Window Size). A terminal emulator like xterm(1) should set the size. A network server like sshd(1) should copy the size from its client. Other devices, such as plain serial ports, might not know the window size.

Works with: BSD version 4.4
#include <sys/ioctl.h>	/* ioctl, TIOCGWINSZ */
#include <err.h> /* err */
#include <fcntl.h> /* open */
#include <stdio.h> /* printf */
#include <unistd.h> /* close */
 
int
main()
{
struct winsize ws;
int fd;
 
/* Open the controlling terminal. */
fd = open("/dev/tty", O_RDWR);
if (fd < 0)
err(1, "/dev/tty");
 
/* Get window size of terminal. */
if (ioctl(fd, TIOCGWINSZ, &ws) < 0)
err(1, "/dev/tty");
 
printf("%d rows by %d columns\n", ws.ws_row, ws.ws_col);
printf("(%d by %d pixels)\n", ws.ws_xpixel, ws.ws_ypixel);
 
close(fd);
return 0;
}

Windows[edit]

Grab a console screen handle, then call GetConsoleScreenBufferInfo() to get the information. Most consoles have a scroll bar and hold hundreds of lines, but the window shows only 25 or 50 lines. Use the window coordinates to calculate the window size.

Works with: MinGW
#include <windows.h>
#include <wchar.h>
 
int
main()
{
HANDLE console;
CONSOLE_SCREEN_BUFFER_INFO info;
short rows;
short columns;
/* Create a handle to the console screen. */
console = CreateFileW(L"CONOUT$", GENERIC_READ | GENERIC_WRITE,
FILE_SHARE_READ | FILE_SHARE_WRITE, NULL, OPEN_EXISTING,
0, NULL);
if (console == INVALID_HANDLE_VALUE)
return 1;
 
/* Calculate the size of the console window. */
if (GetConsoleScreenBufferInfo(console, &info) == 0)
return 1;
CloseHandle(console);
columns = info.srWindow.Right - info.srWindow.Left + 1;
rows = info.srWindow.Bottom - info.srWindow.Top + 1;
 
wprintf(L"%d columns by %d rows\n", columns, rows);
 
return 0;
}

C#[edit]

The C# console has several properties to take note of. BufferHeight and BufferWidth are the valid writing area, the cursor can print anywhere within these bounds. This can be considered the actual terminal. WindowHeight and WindowWidth are simply the size of the window, it only represents the active viewing area which may be larger or more commonly smaller than the size of the buffer.

 
static void Main(string[] args)
{
int bufferHeight = Console.BufferHeight;
int bufferWidth = Console.BufferWidth;
int windowHeight = Console.WindowHeight;
int windowWidth = Console.WindowWidth;
 
Console.Write("Buffer Height: ");
Console.WriteLine(bufferHeight);
Console.Write("Buffer Width: ");
Console.WriteLine(bufferWidth);
Console.Write("Window Height: ");
Console.WriteLine(windowHeight);
Console.Write("Window Width: ");
Console.WriteLine(windowWidth);
Console.ReadLine();
}
 

On the author's system this results in the following output:

Buffer Height: 300
Buffer Width: 80
Window Height: 25
Window Width: 80

This perfectly demonstrates that the buffer may not be the same size as the window.

COBOL[edit]

Works with: OpenCOBOL
       IDENTIFICATION DIVISION.
PROGRAM-ID. terminal-dimensions.
 
DATA DIVISION.
WORKING-STORAGE SECTION.
01 num-lines PIC 9(3).
01 num-cols PIC 9(3).
 
SCREEN SECTION.
01 display-screen.
03 LINE 01 COL 01 PIC 9(3) FROM num-lines.
03 LINE 01 COL 05 VALUE "rows by " .
03 LINE 01 COL 13 PIC 9(3) FROM num-cols.
03 LINE 01 COL 16 VALUE " columns.".
 
PROCEDURE DIVISION.
ACCEPT num-lines FROM LINES
ACCEPT num-cols FROM COLUMNS
 
DISPLAY display-screen
 
* This pauses the program, as ncurses will immediately revert
* back to the console when the program ends.
CALL "C$SLEEP" USING BY CONTENT 3
 
GOBACK
.

Euphoria[edit]

include graphics.e
 
sequence vc
integer term_height, term_width
 
vc = video_config()
 
term_height = vc[VC_LINES]
term_width = vc[VC_COLUMNS]
 
printf(1,"Terminal height is %d\n",term_height)
printf(1,"Terminal width is %d\n",term_width)

F#[edit]

Translation of: C#
open System
 
let bufferHeight = Console.BufferHeight
let bufferWidth = Console.BufferWidth
let windowHeight = Console.WindowHeight
let windowWidth = Console.WindowWidth
 
Console.Write("Buffer Height: ")
Console.WriteLine(bufferHeight)
Console.Write("Buffer Width: ")
Console.WriteLine(bufferWidth)
Console.Write("Window Height: ")
Console.WriteLine(windowHeight)
Console.Write("Window Width: ")
Console.WriteLine(windowWidth)
Console.ReadLine()

Forth[edit]

Works with: GNU Forth
Works with: SwiftForth
variable term-width
variable term-height
 
s" gforth" environment? [if]
2drop form ( height width )
[else] \ SwiftForth
get-size ( width height ) swap
[then]
term-width ! term-height !

Go[edit]

Sub-repository[edit]

package main
 
import (
"fmt"
"os"
 
"golang.org/x/crypto/ssh/terminal"
)
 
func main() {
w, h, err := terminal.GetSize(int(os.Stdout.Fd()))
if err != nil {
fmt.Println(err)
return
}
fmt.Println(h, w)
}

External command[edit]

package main
 
import (
"fmt"
"os"
"os/exec"
)
 
func main() {
var h, w int
cmd := exec.Command("stty", "size")
cmd.Stdin = os.Stdin
d, _ := cmd.Output()
fmt.Sscan(string(d), &h, &w)
fmt.Println(h, w)
}

Ncurses[edit]

Library: curses
package main
 
import (
"fmt"
"log"
 
"code.google.com/p/goncurses"
)
 
func main() {
s, err := goncurses.Init()
if err != nil {
log.Fatal("init:", err)
}
defer goncurses.End()
height, width := s.MaxYX()
fmt.Println(height, width)
}

J[edit]

This is not well supported in J, but since the terminal window can be resized at any time and can have its font changed and so on, good design generally dictates that this kind of information be ignored.

Nevertheless, assuming J version 6 in its usual environment, to determine its width and height, in pixels, you can use:

_2 {.qsmsize_jijs_''

Note also that this will typically include 37 extra pixels horizontally and 79 extra pixels vertically, which are not available to display text. In other words, if the result was 700 500 you would really have 663 pixels of width and 421 pixels of height.

Locomotive Basic[edit]

Locomotive BASIC has no built-in command to get window dimensions, but there is a firmware call to &bb69 (TXT_GET_WINDOW) for this. So we have to use a snippet of Z80 machine code to call the firmware and copy the results from the DE and HL registers to RAM. It looks like this when disassembled:

4000 d5          push de
4001 e5 push hl
4002 cd 69 bb call &bb69
4005 ed 53 20 40 ld (&4020),de
4009 22 22 40 ld (&4022),hl
400c e1 pop hl
400d d1 pop de
400e c9 ret

This routine gets POKEd into RAM (starting at address &4000) and CALLed from Locomotive BASIC, then the results are retrieved with PEEK:

10 s=&4000:SYMBOL AFTER 256:MEMORY s-1
20 FOR i=0 to 14:READ a:POKE s+i,a:NEXT
30 DATA &d5,&e5,&cd,&69,&bb,&ed,&53,&20,&40,&22,&22,&40,&e1,&d1,&c9
40 CALL s
50 h=PEEK(&4020)-PEEK(&4022)+1
60 w=PEEK(&4021)-PEEK(&4023)+1
70 PRINT "window width:"; w; ", height:"; h

In practice, one would prefer to write the machine code routine as a slightly more elaborate RSX (resident system extension) which is a freely relocatable and therefore more reusable Locomotive BASIC extension. The RSX routine might be called "getwh" and accept pointers to integers, which would simplify the BASIC code to:

10 w%=0:h%=0      ' initialize and force integer type
20 |getwh,@w%,@h% ' call RSX and pass variables as pointers
30 PRINT "window width:"; w%; ", height:"; h%

Mathematica[edit]

WIDTH=RunThrough["tput cols", ""];
HEIGHT=RunThrough["tput lines", ""];

OCaml[edit]

Using the library ANSITerminal in the interactive loop:

$ ocaml unix.cma -I +ANSITerminal ANSITerminal.cma
 
# let width, height = ANSITerminal.size () ;;
val width : int = 126
val height : int = 47

Perl[edit]

use Term::Size;
 
($cols, $rows) = Term::Size::chars;
print "The terminal has $cols columns and $rows lines\n";

Perl 6[edit]

Using stty just for the heck of it.

my $stty = qx[stty -a];
my $lines = $stty.match(/ 'rows ' <( \d+/);
my $cols = $stty.match(/ 'columns ' <( \d+/);
say "$lines $cols";

Phix[edit]

The buffer is usually somewhat larger (and never smaller) than the current physical screen size. I would guess that most applications are more interested in the latter.

sequence vc = video_config()
printf(1,"Terminal buffer height is %d\n",vc[VC_LINES])
printf(1,"Terminal buffer width is %d\n",vc[VC_COLUMNS])
printf(1,"Terminal screen height is %d\n",vc[VC_SCRNLINES])
printf(1,"Terminal screen width is %d\n",vc[VC_SCRNCOLS])
Output:
Terminal buffer height is 196
Terminal buffer width is 132
Terminal screen height is 25
Terminal screen width is 80

PicoLisp[edit]

(setq
Width (in '(tput cols) (read))
Height (in '(tput lines) (read)) )

PureBasic[edit]

PureBasic does not have native functions for reading the size of this window, but supports API-functions that allows this.

This code is for Windows only.

Macro ConsoleHandle()
GetStdHandle_( #STD_OUTPUT_HANDLE )
EndMacro
 
Procedure ConsoleWidth()
Protected CBI.CONSOLE_SCREEN_BUFFER_INFO
Protected hConsole = ConsoleHandle()
GetConsoleScreenBufferInfo_( hConsole, @CBI )
ProcedureReturn CBI\srWindow\right - CBI\srWindow\left + 1
EndProcedure
 
Procedure ConsoleHeight()
Protected CBI.CONSOLE_SCREEN_BUFFER_INFO
Protected hConsole = ConsoleHandle()
GetConsoleScreenBufferInfo_( hConsole, @CBI )
ProcedureReturn CBI\srWindow\bottom - CBI\srWindow\top + 1
EndProcedure
 
If OpenConsole()
x$=Str(ConsoleWidth())
y$=Str(ConsoleHeight())
PrintN("This window is "+x$+"x"+y$+ " chars.")
;
Print(#CRLF$+"Press ENTER to exit"):Input()
EndIf

Python[edit]

Works with: Python version 2.6
Library: ctypes

This uses the ctypes library in order to get the console dimensions on Windows. This code is a slight refactoring of an ActiveState Recipe. For Linux, the tput utility is used.

import os
 
def get_windows_terminal():
from ctypes import windll, create_string_buffer
h = windll.kernel32.GetStdHandle(-12)
csbi = create_string_buffer(22)
res = windll.kernel32.GetConsoleScreenBufferInfo(h, csbi)
 
#return default size if actual size can't be determined
if not res: return 80, 25
 
import struct
(bufx, bufy, curx, cury, wattr, left, top, right, bottom, maxx, maxy)\
= struct.unpack("hhhhHhhhhhh", csbi.raw)
width = right - left + 1
height = bottom - top + 1
 
return width, height
 
def get_linux_terminal():
width = os.popen('tput cols', 'r').readline()
height = os.popen('tput lines', 'r').readline()
 
return int(width), int(height)
 
print get_linux_terminal() if os.name == 'posix' else get_windows_terminal()
 

Racket[edit]

 
#lang racket
(require (planet neil/charterm:3:0))
(with-charterm
(charterm-screen-size))
 

Retro[edit]

This information is provided by Retro in the ch (height) and cw (width) variables. You can manually obtain it using the io ports.

-3 5 out wait 5 in !cw
-4 5 out wait 5 in !ch

REXX[edit]

Using TPUT under Linux/Unix[edit]

Works with: brexx
Works with: regina
Works with: rexximc

Some REXX interpreters don't provide basic terminal control as part of the language. However, it's possible to determine the size of the terminal window by using external system commands:

width = 'tput'( 'cols' )
height = 'tput'( 'lines' )
 
say 'The terminal is' width 'characters wide'
say 'and has' height 'lines'

LINESIZE[edit]

The LINESIZE built-in function returns the (terminal) screen's width.   It is supported by most (classic) REXX interpreters (and some others) such as: CMS REXX, TSO REXX, VSE REXX, the IBM REXX compiler, PC/REXX, Personal REXX, REXX/imc, R4 and ROO.   A sample usage of it is:

width=linesize()

The above example makes use of   LINESIZE   REXX program (or BIF) which is used to determine the screen width (or linesize) of the terminal (console).
The   LINESIZE.REX   REXX program is included here ──► LINESIZE.REX.

SCRSIZE[edit]

SCRSIZE is another built-in function, and returns two integers: the screen depth and the screen width.   A few classic REXX interpreters support it:   PC/REXX, Personal REXX, R4 and ROO.

 parse value scrsize() with sd sw

The above example makes use of   SCRSIZE   REXX program (of BIF) which is used to determine the screen size of the terminal (console).
The   SCRSIZE.REX   REXX program is included here ──► SCRSIZE.REX.

Ring[edit]

 
system("mode 50,20")
 

Ruby[edit]

def winsize
# Ruby 1.9.3 added 'io/console' to the standard library.
require 'io/console'
IO.console.winsize
rescue LoadError
# This works with older Ruby, but only with systems
# that have a tput(1) command, such as Unix clones.
[Integer(`tput li`), Integer(`tput co`)]
end
 
rows, cols = winsize
printf "%d rows by %d columns\n", rows, cols

Library: curses
[edit]

Curses.lines and Curses.cols return the size of the terminal. The program must call Curses.init_screen, because without this call, Curses might report 0 lines and 0 columns. Beware that Curses.init_screen also switches the terminal to screen-oriented mode, and fails on those terminals that cannot support curses.

require 'curses'
 
begin
Curses.init_screen
 
r, c = Curses.lines, Curses.cols
 
Curses.setpos r / 2, 0
Curses.addstr "#{r} rows by #{c} columns".center(c)
Curses.getch
ensure
Curses.close_screen
end

Seed7[edit]

The functions height and width are portable and determine the dimensions of the console window. Height and width are based on terminfo respectively the Windows console API.

$ include "seed7_05.s7i";
include "console.s7i";
 
const proc: main is func
local
var text: console is STD_NULL;
begin
console := open(CONSOLE);
writeln(console, "height: " <& height(console) lpad 3);
writeln(console, "width: " <& width(console) lpad 3);
# Terminal windows often restore the previous
# content, when a program is terminated. Therefore
# the program waits until Return/Enter is pressed.
readln;
end func;

Sidef[edit]

Translation of: Perl 6
var stty = `stty -a`;
var lines = stty.match(/\brows\h+(\d+)/);
var cols = stty.match(/\bcolumns\h+(\d+)/);
say "#{lines} #{cols}";
Output:
24 80

Tcl[edit]

Translation of: UNIX Shell
set width [exec tput cols]
set height [exec tput lines]
puts "The terminal is $width characters wide and has $height lines"

UNIX Shell[edit]

Works with: Bourne Shell
#!/bin/sh
WIDTH=`tput cols`
HEIGHT=`tput lines`
echo "The terminal is $WIDTH characters wide and has $HEIGHT lines."

Library: termcap
[edit]

termcap is obsolete.
#!/bin/sh
WIDTH=`tput co`
HEIGHT=`tput li`
echo "The terminal is $WIDTH characters wide and has $HEIGHT lines."

C Shell[edit]

#!/bin/csh -f
set WIDTH=`tput cols`
set HEIGHT=`tput lines`
echo "The terminal is $WIDTH characters wide and has $HEIGHT lines."

Visual Basic[edit]

Translation of: C#
Module Module1
 
Sub Main()
Dim bufferHeight = Console.BufferHeight
Dim bufferWidth = Console.BufferWidth
Dim windowHeight = Console.WindowHeight
Dim windowWidth = Console.WindowWidth
 
Console.Write("Buffer Height: ")
Console.WriteLine(bufferHeight)
Console.Write("Buffer Width: ")
Console.WriteLine(bufferWidth)
Console.Write("Window Height: ")
Console.WriteLine(windowHeight)
Console.Write("Window Width: ")
Console.WriteLine(windowWidth)
End Sub
 
End Module
Output:

I put the built application in Desktop:

\Desktop>ConsoleApplication1
Buffer Height: 300
Buffer Width: 80
Window Height: 25
Window Width: 80

\Desktop>

After resizing the console:

\Desktop>ConsoleApplication1
Buffer Height: 300
Buffer Width: 80
Window Height: 14
Window Width: 49

\Desktop>

XPL0[edit]

include c:\cxpl\codes;
int W, H;
[W:= Peek($40, $4A); \IBM-PC BIOS data
H:= Peek($40, $84) + 1;
Text(0, "Terminal width and height = ");
IntOut(0, W); ChOut(0, ^x); IntOut(0, H);
]

Output:

80x25

zkl[edit]

Unix specific solution:

Translation of: GO
h,w:=System.popen("stty size","r").readln().split();
println(w," x ",h);
Output:
91 x 24