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22.2. Win32::Console
Win32::Console implements the Win32 console and character mode functions. They give you full control on the console input and output, including support of offscreen console buffers (e.g., multiple screen pages); reading and writing of characters, attributes, and whole portions of the screen; and complete processing of keyboard and mouse events.
The new constructor is used to create a console object. It can take two forms:
$con = Win32::Console->new(standard_handle); $con = Win32::Console->new(accessmode, sharemode);
The first form creates a handle to a standard channel. standard_handle can be one of STD_OUTPUT_HANDLE, STD_ERROR_HANDLE, or STD_INPUT_HANDLE.
The second form creates a console screen buffer in memory, which you can access for reading and writing as a normal console, and then redirect on the standard output (the screen) with Display. In this case, you can specify accessmode to be GENERIC_READ, GENERIC_WRITE, or both, determining the permissions you will have on the created buffer.
sharemode affects how the console can be shared. It can be specified as either FILE_SHARE_READ, FILE_SHARE_WRITE, or both. If you don't specify any of those parameters, all four flags will be used.
The following methods are supported by the Win32::Console module.
| Alloc |
$cons->Alloc
Allocates a new console for the process. Returns undef on error or a nonzero value on success. A process cannot be associated with more than one console, so this method will fail if there is already an allocated console. Use Free to detach the process from the console, and then call Alloc to create a new console.
| Attr |
$cons->Attr([attr])
Gets or sets the current console attribute. This attribute is used by the Write method.
| Cls |
$cons->Cls([attr])
Clears the console with the specified attr, if given. Uses ATTR_NORMAL otherwise.
| Cursor |
$cons->Cursor([x, y, size, visible])
Gets or sets cursor position and appearance. Returns undef on error, or a four-element list containing x, y, size, and visible. x and y give the current cursor position.
| Display |
$cons->Display
Displays the specified console on the screen. Returns undef on error or a nonzero value on success.
| FillAttr |
$cons->FillAttr([value, number, col, row])
Fills the specified number of consecutive attributes, beginning at col, row, with the value specified. Returns the number of attributes filled, or undef on error.
| FillChar |
$cons->FillChar(char, number, col, row)
Fills the specified number of consecutive characters, beginning at col, row, with the character specified in char. Returns the number of characters filled, or undef on error.
| Flush |
$cons->Flush
Flushes the console input buffer. All the events in the buffer are discarded. Returns undef on error, a nonzero value on success.
| Free |
$cons->Free
Detaches the process from the console. Returns undef on error, a nonzero value on success.
| GenerateCtrlEvent |
$cons->GenerateCtrlEvent([type, processgroup])
Sends a break signal of the specified type to the specified process group. type can be one of CTRL_BREAK_EVENT or CTRL_C_EVENT, signaling, respectively, the pressing of Ctrl + Break and Ctrl-C. If not specified, type defaults to CTRL_C_EVENT. processgroup is the PID of a process sharing the same console. If omitted, it defaults to 0 (the current process), which is also the only meaningful value that you can pass to this function. Returns undef on error, a nonzero value on success.
| GetEvents |
$cons->GetEvents
Returns the number of unread input events in the console's input buffer, or undef on error.
| Info |
$cons->Info
Returns an array of information about the console, which contains:
-
Number of columns (X size) of the console buffer
-
Number of rows (Y size) of the console buffer
-
Current column (X position) of the cursor
-
Current row (Y position) of the cursor
-
Current attribute used for Write
-
Left column (X of the starting point) of the current console window
-
Top row (Y of the starting point) of the current console window
-
Right column (X of the final point) of the current console window
-
Bottom row (Y of the final point) of the current console window
-
Maximum number of columns for the console window, given the current buffer size, font, and screen size
-
Maximum number of rows for the console window, given the current buffer size, font, and screen size
This example prints the cursor's current position:
@info = $CONSOLE->Info( ); print "Cursor at $info[3], $info[4].0";
| Input |
$cons->Input
Reads an event from the input buffer. Returns a list of values, determined by the type of event. A keyboard event will contain the following values, in order:
-
Event type (1 for keyboard)
-
Key state—true if the key is being pressed, false if the key is being released
-
Repeat count—the number of times the key is held down
-
Virtual keycode of the key
-
Virtual scancode of the key
-
ASCII code of the character (if the key is a character key, 0 otherwise)
-
State of the control keys (Shifts, Ctrls, Alts, etc.)
A mouse event will return the following values, in order:
-
Event type (2 for mouse)
-
X coordinate (column) of the mouse location
-
Y coordinate (row) of the mouse location
-
Button state—the mouse button(s) that are pressed
-
State of the control keys (Shifts, Ctrls, Alts, etc.)
-
Event flags for the type of the mouse event
| InputChar |
$cons->InputChar(number)
Reads and returns number characters from the console input buffer, or returns undef on error.
| InputCP |
$cons->InputCP([codepage])
Gets or sets the input code page used by the console. Note that this doesn't apply to a console object, but to the standard input console. This attribute is used by the Write method.
| MaxWindow |
$cons->MaxWindow
Returns the size of the largest possible console window, based on the current font and the size of the display. The result is undef on error; otherwise, a two-element list containing the number of columns and rows is returned.
| Mode |
$cons->Mode([flags])
Gets or sets the input or output mode of a console. flags can be a combination of the following constants:
ENABLE_LINE_INPUT ENABLE_ECHO_INPUT ENABLE_PROCESSED_INPUT ENABLE_WINDOW_INPUT ENABLE_MOUSE_INPUT ENABLE_PROCESSED_OUTPUT ENABLE_WRAP_AT_EOL_OUTPUT
| OutputCP |
$cons->OutputCP([codepage])
Gets or sets the output code page used by the console. Note that this doesn't apply to a console object, but to the standard output console. You may want to use the noninstantiated form to avoid confusion:
$codepage = Win32::Console::OutputCP( ); Win32::Console::OutputCP(437);
| PeekInput |
$cons->PeekInput
Does exactly the same as Input, except that the event read is not removed from the input buffer.
| ReadAttr |
$cons->ReadAttr([number, col, row])
Reads the specified number of consecutive attributes from the console, beginning at col, row. Returns the attributes read (a variable containing one character for each attribute), or undef on error. You can then pass the returned variable to WriteAttr to restore the saved attributes on screen.
| ReadChar |
$cons->ReadChar([number, col, row])
Reads the specified number of consecutive characters from the console, beginning at col, row. Returns a string containing the characters read, or undef on error. You can then pass the returned variable to WriteChar to restore the saved characters on screen.
| ReadRect |
$cons->ReadRect(left, top, right, bottom)
Reads the content (characters and attributes) of the rectangle specified by left, top, right, and bottom from the console. Returns a string containing the rectangle read, or undef on error. You can then pass the returned variable to WriteRect to restore the saved rectangle on screen (or on another console).
| Scroll |
$cons->Scroll(left, top, right, bottom, col, row, char, attr, [cleft, ctop, cright, cbottom])
Moves a block of data in a console buffer; the block is identified by the left, top, right, and bottom positions.
# Scrolls the screen 10 lines down, filling with black spaces $CONSOLE->Scroll(0, 0, 80, 25, 0, 10, " ", $FG_BLACK | $BG_BLACK);
| Select |
$cons->Select(standard_handle)
Redirects a standard handle to the specified console. standard_handlecan have one of the following values:
STD_INPUT_HANDLE STD_OUTPUT_HANDLE STD_ERROR_HANDLE
| Window |
$cons->Window([flag, left, top, right, bottom])
Gets or sets the current console window size. If called without arguments, returns a four-element list containing the current window coordinates in the form of (left, top, right, bottom). To set the window size, you have to specify an additional flag parameter. If it is 0, coordinates are considered relative to the current coordinates; if it is nonzero, coordinates are absolute.
| Write |
$cons->Write(string)
Writes stringon the console, using the current attribute, which you can set with Attr, and advances the cursor as needed. This isn't that different from Perl's print statement. Returns the number of characters written, or undef on error.
| WriteAttr |
$cons->WriteAttr(attrs, col, row)
Writes the attributes contained in the string <attrs>, beginning at col, row, without affecting the characters that are on screen. The string attrs can be the result of a ReadAttr function, or you can build your own attribute string; in this case, keep in mind that every attribute is treated as a character, not a number (see example). Returns the number of attributes written, or undef on error.
$CONSOLE->WriteAttr($attrs, 0, 0); # note the use of chr( )... $attrs = chr($FG_BLACK | $BG_WHITE) x 80; $CONSOLE->WriteAttr($attrs, 0, 0);
| WriteChar |
$cons->WriteChar(chars, col, row)
Writes the characters in the string attr, beginning at col, row, without affecting the attributes that are onscreen. The string characters can be the result of a ReadChar function or a normal string. Returns the number of characters written, or undef on error.
| WriteInput |
$cons->WriteInput(event)
Pushes data in the console input buffer. event is a list of values (for more information, see Input). The string characters can be the result of a ReadChar function or a normal string. Returns the number of characters written, or undef on error.
| WriteRect |
$cons->WriteRect(rect, left, top, right, bottom)
Writes a rectangle of characters and attributes (contained in rect) on the console at the coordinates specified by left, top, right, and bottom. rectcan be the result of a ReadRect function. Returns undef on error; otherwise, returns a four-element list containing the coordinates of the affected rectangle, in the format (left, top, right, bottom).
22.2.1. Constants
The following constants are exported in the main namespace of your script using Win32::Console:
BACKGROUND_BLUE BACKGROUND_GREEN BACKGROUND_INTENSITY BACKGROUND_RED CAPSLOCK_ON CONSOLE_TEXTMODE_BUFFER ENABLE_ECHO_INPUT ENABLE_LINE_INPUT ENABLE_MOUSE_INPUT ENABLE_PROCESSED_INPUT ENABLE_PROCESSED_OUTPUT ENABLE_WINDOW_INPUT ENABLE_WRAP_AT_EOL_OUTPUT ENHANCED_KEY FILE_SHARE_READ FILE_SHARE_WRITE FOREGROUND_BLUE FOREGROUND_GREEN FOREGROUND_INTENSITY FOREGROUND_RED LEFT_ALT_PRESSED LEFT_CTRL_PRESSED NUMLOCK_ON GENERIC_READ GENERIC_WRITE RIGHT_ALT_PRESSED RIGHT_CTRL_PRESSED SCROLLLOCK_ON SHIFT_PRESSED STD_INPUT_HANDLE STD_OUTPUT_HANDLE STD_ERROR_HANDLE
Additionally, the following variables can be used:
$FG_BLACK $FG_BLUE $FG_LIGHTBLUE $FG_RED $FG_LIGHTRED $FG_GREEN $FG_LIGHTGREEN $FG_MAGENTA $FG_LIGHTMAGENTA $FG_CYAN $FG_LIGHTCYAN $FG_BROWN $FG_YELLOW $FG_GRAY $FG_WHITE $BG_BLACK $BG_BLUE $BG_LIGHTBLUE $BG_RED $BG_LIGHTRED $BG_GREEN $BG_LIGHTGREEN $BG_MAGENTA $BG_LIGHTMAGENTA $BG_CYAN $BG_LIGHTCYAN $BG_BROWN $BG_YELLOW $BG_GRAY $BG_WHITE $ATTR_NORMAL $ATTR_INVERSE
ATTR_NORMAL is set to gray foreground on black background (DOS's standard colors).
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