Terminal control/Positional read: Difference between revisions

{{task|Terminal control}}[[Terminal Control::task| ]]

Determine the character displayed on the screen at column 3, row 6 and store that character in a variable. Note that it is permissible to utilize system or language provided methods or system provided facilities, system maintained records or available buffers or system maintained display records to achieve this task, rather than query the terminal directly, if those methods are more usual for the system type or language.

 

=={{header|AutoHotkey}}==

{{works with|AutoHotkey_L}}

<p>AutoHotkey is not built for the command line, so we need call the WinAPI directly.</p><p>For fun, this writes random characters to the command window so that it has something to retrieve. </p>

hConsole := DllCall( "GetStdHandle", int, STDOUT := -11 )

Loop 10

return out

return 0

 

=={{header|BASIC}}==

==={{header|Applesoft BASIC}}===

 

 

 

Amstrad CPC screen memory only stores pixels but no character information (as opposed to e.g. the C64), so the firmware routine (TXT_UNWRITE) called by BASIC works by trying to find a match between screen pixels and the shape of a currently defined character. If the character table or screen pixels in the area of the character are changed between writing and reading, COPYCHR$ will therefore fail.

 

===[[QuickBASIC#QBasic|QBasic]]===

The top left corner is (1, 1).

 

 

==={{header|ZX Spectrum Basic}}===

20 REM So we subtract one from the coordinates

 

 

=={{header|C}}==

 

{{libheader|Win32}}

#include <wchar.h>

 

wprintf(L"Character at (3, 6) had been '%lc'\n", c);

return 0;

 

=={{header|Common Lisp}}==

==={{header|ncurses}}===

To interface the ncurses C library from Lisp, the ''croatoan'' library is used.

(with-screen (scr :input-blocking t :input-echoing nil :cursor-visible nil)

;; print random characters in a 10x20 grid

(format scr "extracted char: ~A" char))

(refresh scr)

 

=={{header|Go}}==

{{trans|Kotlin}}

 

/*

}

fmt.Printf("The character at column 3, row 6 is '%c'\n", c)

 

{{out}}

=={{header|Julia}}==

{{trans|Raku}}

 

randtxt(n) = foldl(*, rand(split("1234567890abcdefghijklmnopqrstuvwxyz", ""), n))

ch = LibNCurses.winch(row, col)

LibNCurses.mvwaddstr(col, 52, "The character at ($row, $col) is $ch.") )

 

=={{header|Kotlin}}==

This is based on the C entry and works on Windows 10:

 

import kotlinx.cinterop.*

else println("Something went wrong!")

}

 

{{out}}

 

=={{header|Ksh}}==

#!/bin/ksh

 

move 14 1

refresh

 

{{out}}<pre>

{{libheader|nim-ncurses}}

This Nim version is inspired by Raku and Julia versions.

import ncurses

 

discard getch()

 

 

{{out}}

=={{header|Perl}}==

{{trans|Raku}}

 

use strict;

$win->getch;

 

 

=={{header|Phix}}==

{{out}}

<pre>

=={{header|PowerShell}}==

This gets the character at position (3, 6) of the ''buffer'', not necessarily of the screen.

$coord = [System.Management.Automation.Host.Coordinates]::new(3, 6)

$rect = [System.Management.Automation.Host.Rectangle]::new($coord, $coord)

$char = $Host.UI.RawUI.GetBufferContents($rect).Character

 

=={{header|Python}}==

from random import randint

 

 

curses.endwin()

 

{{out}}

=={{header|Racket}}==

Works in a CMD box on Windows:

#lang racket

(require ffi/unsafe ffi/unsafe/define)

(and (ReadConsoleOutputCharacterA (GetStdHandle -11) b 1 #x50002)

(printf "The character at 3x6 is <~a>\n" b))

 

=={{header|Raku}}==

(formerly Perl 6)

{{trans|Python}}

 

# Reference:

delwin($win) if $win;

endwin;

 

{{out}}

{{works with|PC/REXX}}

{{works with|Personal REXX}}

row = 6 /*point to a particular row on screen*/

col = 3 /* " " " " column " " */

 

other = scrRead(40, 3, 1) /*same thing, but for row forty. */

 

=={{header|TXR}}==

 

(typedef BOOL (enum BOOL FALSE TRUE))

(unless (plusp [nread 0])

(error "ReadConsoleOutputCharacter read zero characters"))

 

Notes:

{{libheader|ncurses}}

An embedded program so we can ask the C host to communicate with ncurses for us.

 

import "random" for Random

// clean-up

win.delwin()

<br>

We now embed this in the following C program, compile and run it.

#include <stdlib.h>

#include <string.h>

WrenVM* vm = wrenNewVM(&config);

const char* module = "main";

char *script = readFile(fileName);

WrenInterpretResult result = wrenInterpret(vm, module, script);

free(script);

return 0;

 

{{out}}

 

=={{header|XPL0}}==

int C;

[Cursor(3, 6); \move cursor to column 3, row 6 (top left = 0,0)

\Call BIOS interrupt routine to read character (& attribute) at cursor position

C:= CallInt($10, $0800, 0) & $00FF; \mask off attribute, leaving the character

 

{{omit from|ACL2}}