src/include/gpxe/ansiesc.h

   1 #ifndef _GPXE_ANSIESC_H
   2 #define _GPXE_ANSIESC_H
   3
   4 /** @file
   5  *
   6  * ANSI escape sequences
   7  *
   8  * ANSI X3.64 (aka ECMA-48 or ISO/IEC 6429, available from
   9  * http://www.ecma-international.org/publications/files/ECMA-ST/Ecma-048.pdf)
  10  * defines escape sequences consisting of:
  11  *
  12  *     A Control Sequence Introducer (CSI)
  13  *
  14  *     Zero or more Parameter Bytes (P)
  15  *
  16  *     Zero or more Intermediate Bytes (I)
  17  *
  18  *     A Final Byte (F)
  19  *
  20  * The CSI consists of ESC (0x1b) followed by "[" (0x5b).  The
  21  * Parameter Bytes, for a standardised (i.e. not private or
  22  * experimental) sequence, consist of a list of ASCII decimal integers
  23  * separated by semicolons.  The Intermediate Bytes (in the range 0x20
  24  * to 0x2f) and the Final Byte (in the range 0x40 to 0x4f) determine
  25  * the control function.
  26  *
  27  */
  28
  29 FILE_LICENCE ( GPL2_OR_LATER );
  30
  31 /** A handler for an escape sequence */
  32 struct ansiesc_handler {
  33         /** The control function identifier
  34          *
  35          * The control function identifier consists of the
  36          * Intermediate Bytes (if any) and the Final Byte.  In
  37          * practice, no more than one immediate byte is ever used, so
  38          * the byte combination can be efficiently expressed as a
  39          * single integer, in the obvious way (with the Final Byte
  40          * being the least significant byte).
  41          */
  42         unsigned int function;
  43         /** Handle escape sequence
  44          *
  45          * @v count             Parameter count
  46          * @v params            Parameter list
  47          *
  48          * A negative parameter value indicates that the parameter was
  49          * omitted and that the default value for this control
  50          * function should be used.
  51          *
  52          * Since all parameters are optional, there is no way to
  53          * distinguish between "zero parameters" and "single parameter
  54          * omitted".  Consequently, the parameter list will always
  55          * contain at least one item.
  56          */
  57         void ( * handle ) ( unsigned int count, int params[] );
  58 };
  59
  60 /** Maximum number of parameters within a single escape sequence */
  61 #define ANSIESC_MAX_PARAMS 4
  62
  63 /**
  64  * ANSI escape sequence context
  65  *
  66  * This provides temporary storage for processing escape sequences,
  67  * and points to the list of escape sequence handlers.
  68  */
  69 struct ansiesc_context {
  70         /** Array of handlers
  71          *
  72          * Must be terminated by a handler with @c function set to
  73          * zero.
  74          */
  75         struct ansiesc_handler *handlers;
  76         /** Parameter count
  77          *
  78          * Will be zero when not currently in an escape sequence.
  79          */
  80         unsigned int count;
  81         /** Parameter list */
  82         int params[ANSIESC_MAX_PARAMS];
  83         /** Control function identifier */
  84         unsigned int function;
  85 };
  86
  87 /** Escape character */
  88 #define ESC 0x1b
  89
  90 /** Control Sequence Introducer */
  91 #define CSI "\033["
  92
  93 /**
  94  * @defgroup ansifuncs ANSI escape sequence function identifiers
  95  * @{
  96  */
  97
  98 /** Cursor position */
  99 #define ANSIESC_CUP 'H'
 100
 101 /** Erase in page */
 102 #define ANSIESC_ED 'J'
 103
 104 /** Erase from cursor to end of page */
 105 #define ANSIESC_ED_TO_END 0
 106
 107 /** Erase from start of page to cursor */
 108 #define ANSIESC_ED_FROM_START 1
 109
 110 /** Erase whole page */
 111 #define ANSIESC_ED_ALL 2
 112
 113 /** Select graphic rendition */
 114 #define ANSIESC_SGR 'm'
 115
 116 /** @} */
 117
 118 extern int ansiesc_process ( struct ansiesc_context *ctx, int c );
 119
 120 #endif /* _GPXE_ANSIESC_H */