iPXE
ansiesc.c
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1 /*
2  * Copyright (C) 2006 Michael Brown <mbrown@fensystems.co.uk>.
3  *
4  * This program is free software; you can redistribute it and/or
5  * modify it under the terms of the GNU General Public License as
6  * published by the Free Software Foundation; either version 2 of the
7  * License, or any later version.
8  *
9  * This program is distributed in the hope that it will be useful, but
10  * WITHOUT ANY WARRANTY; without even the implied warranty of
11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
12  * General Public License for more details.
13  *
14  * You should have received a copy of the GNU General Public License
15  * along with this program; if not, write to the Free Software
16  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
17  * 02110-1301, USA.
18  *
19  * You can also choose to distribute this program under the terms of
20  * the Unmodified Binary Distribution Licence (as given in the file
21  * COPYING.UBDL), provided that you have satisfied its requirements.
22  */
23 
24 FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL );
25 
26 #include <string.h>
27 #include <assert.h>
28 #include <ipxe/ansiesc.h>
29 
30 /** @file
31  *
32  * ANSI escape sequences
33  *
34  */
35 
36 /**
37  * Call ANSI escape sequence handler
38  *
39  * @v ctx ANSI escape sequence context
40  * @v function Control function identifier
41  * @v count Parameter count
42  * @v params Parameter list
43  */
45  unsigned int function, int count,
46  int params[] ) {
47  struct ansiesc_handler *handlers = ctx->handlers;
48  struct ansiesc_handler *handler;
49 
50  for ( handler = handlers ; handler->function ; handler++ ) {
51  if ( handler->function == function ) {
52  handler->handle ( ctx, count, params );
53  break;
54  }
55  }
56 }
57 
58 /**
59  * Process character that may be part of ANSI escape sequence
60  *
61  * @v ctx ANSI escape sequence context
62  * @v c Character
63  * @ret c Original character if not part of escape sequence
64  * @ret <0 Character was part of escape sequence
65  *
66  * ANSI escape sequences will be plucked out of the character stream
67  * and interpreted; once complete they will be passed to the
68  * appropriate handler if one exists in this ANSI escape sequence
69  * context.
70  *
71  * In the interests of code size, we are rather liberal about the
72  * sequences we are prepared to accept as valid.
73  */
74 int ansiesc_process ( struct ansiesc_context *ctx, int c ) {
75 
76  if ( ctx->count == 0 ) {
77  if ( c == ESC ) {
78  /* First byte of CSI : begin escape sequence */
79  ctx->count = 1;
80  memset ( ctx->params, 0xff, sizeof ( ctx->params ) );
81  ctx->function = 0;
82  return -1;
83  } else {
84  /* Normal character */
85  return c;
86  }
87  } else {
88  if ( c == '[' ) {
89  /* Second byte of CSI : do nothing */
90  } else if ( ( c >= '0' ) && ( c <= '9' ) ) {
91  /* Parameter Byte : part of a parameter value */
92  int *param = &ctx->params[ctx->count - 1];
93  if ( *param < 0 )
94  *param = 0;
95  *param = ( ( *param * 10 ) + ( c - '0' ) );
96  } else if ( c == ';' ) {
97  /* Parameter Byte : parameter delimiter */
98  ctx->count++;
99  if ( ctx->count > ( sizeof ( ctx->params ) /
100  sizeof ( ctx->params[0] ) ) ) {
101  /* Excessive parameters : abort sequence */
102  ctx->count = 0;
103  DBG ( "Too many parameters in ANSI escape "
104  "sequence\n" );
105  }
106  } else if ( ( ( c >= 0x20 ) && ( c <= 0x2f ) ) ||
107  ( c == '?' ) ) {
108  /* Intermediate Byte */
109  ctx->function <<= 8;
110  ctx->function |= c;
111  } else {
112  /* Treat as Final Byte. Zero ctx->count before
113  * calling handler to avoid potential infinite loops.
114  */
115  int count = ctx->count;
116  ctx->count = 0;
117  ctx->function <<= 8;
118  ctx->function |= c;
119  ansiesc_call_handler ( ctx, ctx->function,
120  count, ctx->params );
121  }
122  return -1;
123  }
124 }
A handler for an escape sequence.
Definition: ansiesc.h:34
void(* handle)(struct ansiesc_context *ctx, unsigned int count, int params[])
Handle escape sequence.
Definition: ansiesc.h:60
unsigned int function
The control function identifier.
Definition: ansiesc.h:44
ANSI escape sequence context.
Definition: ansiesc.h:73
static __always_inline void off_t int c
Definition: efi_uaccess.h:87
struct golan_eq_context ctx
Definition: CIB_PRM.h:28
int ansiesc_process(struct ansiesc_context *ctx, int c)
Process character that may be part of ANSI escape sequence.
Definition: ansiesc.c:74
Assertions.
ANSI escape sequences.
#define ESC
Escape character.
Definition: ansiesc.h:92
struct hv_monitor_parameter param[4][32]
Parameters.
Definition: hyperv.h:24
FILE_LICENCE(GPL2_OR_LATER_OR_UBDL)
uint16_t count
Number of entries.
Definition: ena.h:22
#define DBG(...)
Print a debugging message.
Definition: compiler.h:498
static void ansiesc_call_handler(struct ansiesc_context *ctx, unsigned int function, int count, int params[])
Call ANSI escape sequence handler.
Definition: ansiesc.c:44
String functions.
void * memset(void *dest, int character, size_t len) __nonnull