The constants below are defined by this extension, and will only be available when the extension has either been compiled into PHP or dynamically loaded at runtime.
PRINTER_COPIES
     (integer)
    PRINTER_MODE
     (integer)
    PRINTER_TITLE
     (integer)
    PRINTER_DEVICENAME
     (integer)
    PRINTER_DRIVERVERSION
     (integer)
    PRINTER_OUTPUT_FILE
     (integer)
    PRINTER_RESOLUTION_Y
     (integer)
    PRINTER_RESOLUTION_X
     (integer)
    PRINTER_SCALE
     (integer)
    PRINTER_BACKGROUND_COLOR
     (integer)
    PRINTER_PAPER_LENGTH
     (integer)
    PRINTER_PAPER_WIDTH
     (integer)
    PRINTER_PAPER_FORMAT
     (integer)
    PRINTER_FORMAT_CUSTOM
     (integer)
    PRINTER_FORMAT_LETTER
     (integer)
    PRINTER_FORMAT_LEGAL
     (integer)
    PRINTER_FORMAT_A3
     (integer)
    PRINTER_FORMAT_A4
     (integer)
    PRINTER_FORMAT_A5
     (integer)
    PRINTER_FORMAT_B4
     (integer)
    PRINTER_FORMAT_B5
     (integer)
    PRINTER_FORMAT_FOLIO
     (integer)
    PRINTER_ORIENTATION
     (integer)
    PRINTER_ORIENTATION_PORTRAIT
     (integer)
    PRINTER_ORIENTATION_LANDSCAPE
     (integer)
    PRINTER_TEXT_COLOR
     (integer)
    PRINTER_TEXT_ALIGN
     (integer)
    PRINTER_TA_BASELINE
     (integer)
    PRINTER_TA_BOTTOM
     (integer)
    PRINTER_TA_TOP
     (integer)
    PRINTER_TA_CENTER
     (integer)
    PRINTER_TA_LEFT
     (integer)
    PRINTER_TA_RIGHT
     (integer)
    PRINTER_PEN_SOLID
     (integer)
    PRINTER_PEN_DASH
     (integer)
    PRINTER_PEN_DOT
     (integer)
    PRINTER_PEN_DASHDOT
     (integer)
    PRINTER_PEN_DASHDOTDOT
     (integer)
    PRINTER_PEN_INVISIBLE
     (integer)
    PRINTER_BRUSH_SOLID
     (integer)
    PRINTER_BRUSH_CUSTOM
     (integer)
    PRINTER_BRUSH_DIAGONAL
     (integer)
    PRINTER_BRUSH_CROSS
     (integer)
    PRINTER_BRUSH_DIAGCROSS
     (integer)
    PRINTER_BRUSH_FDIAGONAL
     (integer)
    PRINTER_BRUSH_HORIZONTAL
     (integer)
    PRINTER_BRUSH_VERTICAL
     (integer)
    PRINTER_FW_THIN
     (integer)
    PRINTER_FW_ULTRALIGHT
     (integer)
    PRINTER_FW_LIGHT
     (integer)
    PRINTER_FW_NORMAL
     (integer)
    PRINTER_FW_MEDIUM
     (integer)
    PRINTER_FW_BOLD
     (integer)
    PRINTER_FW_ULTRABOLD
     (integer)
    PRINTER_FW_HEAVY
     (integer)
    PRINTER_ENUM_LOCAL
     (integer)
    PRINTER_ENUM_NAME
     (integer)
    PRINTER_ENUM_DEFAULT
     (integer)
    PRINTER_ENUM_CONNECTIONS
     (integer)
    PRINTER_ENUM_NETWORK
     (integer)
    PRINTER_ENUM_REMOTE
     (integer)