Ansi Codes define functions that change display graphics, control cursor movement, and reassign keys. An ANSI escape sequence is a sequence of ASCII characters, the first two of which are the escape character (1Bh) and the left-bracket character (5Bh). The character or characters following the escape and left-bracket characters specify an alphanumeric code that controls a keyboard or display function. ANSI escape sequences distinguish between uppercase and lowercase letters; for example, "A" and "a" have completely different meanings.
Parameters used in ANSI escape sequences:
Pn - Numeric parameter. Specifies a decimal number.
Ps - Selective parameter. Specifies a decimal number that you use to select a function. You can specify more than one function by separating the parameters with semicolons.
PL - Line parameter. Specifies a decimal number that represents one of the lines on your display or on another device.
Pc - Column parameter. Specifies a decimal number that represents one of the columns on your screen or on another device.
ANSI escape sequences for cursor movement, graphics, and keyboard settings:
In the following list of ANSI escape sequences, the abbreviation ESC represents the ASCII escape character 27 (1Bh), which appears at the beginning of each escape sequence.
ESC[PL;PcH - Cursor Position: Moves the cursor to the specified position (coordinates). If you do not specify a position, the cursor moves to the home position: the upper-left corner of the screen (line 0, column 0). This escape sequence works the same way as the following Cursor Position escape sequence.
ESC[PL;Pcf - Cursor Position: Works the same way as the preceding Cursor Position escape sequence.
ESC[PnA - Cursor Up: Moves the cursor up by the specified number of lines without changing columns. If the cursor is already on the top line, ANSI.SYS ignores this sequence.
ESC[PnB - Cursor Down: Moves the cursor down by the specified number of lines without changing columns. If the cursor is already on the bottom line, ANSI.SYS ignores this sequence.
ESC[PnC - Cursor Forward: Moves the cursor forward by the specified number of columns without changing lines. If the cursor is already in the rightmost column, ANSI.SYS ignores this sequence.
ESC[PnD - Cursor Backward: Moves the cursor back by the specified number of columns without changing lines. If the cursor is already in the leftmost column, ANSI.SYS ignores this sequence.
ESC[s - Save Cursor Position: Saves the current cursor position. You can move the cursor to the saved cursor position by using the Restore Cursor Position sequence.
ESC[u - Restore Cursor Position: Returns the cursor to the position stored by the Save Cursor Position sequence.
ESC[2J - Erase Display: Clears the screen and moves the cursor to the home position (line 0, column 0).
ESC[K - Erase Line: Clears all characters from the cursor position to the end of the line (including the character at the cursor position).
