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acgetline.c revision 1.1.1.8
      1 /******************************************************************************
      2  *
      3  * Module Name: acgetline - local line editing
      4  *
      5  *****************************************************************************/
      6 
      7 /*
      8  * Copyright (C) 2000 - 2019, Intel Corp.
      9  * All rights reserved.
     10  *
     11  * Redistribution and use in source and binary forms, with or without
     12  * modification, are permitted provided that the following conditions
     13  * are met:
     14  * 1. Redistributions of source code must retain the above copyright
     15  *    notice, this list of conditions, and the following disclaimer,
     16  *    without modification.
     17  * 2. Redistributions in binary form must reproduce at minimum a disclaimer
     18  *    substantially similar to the "NO WARRANTY" disclaimer below
     19  *    ("Disclaimer") and any redistribution must be conditioned upon
     20  *    including a substantially similar Disclaimer requirement for further
     21  *    binary redistribution.
     22  * 3. Neither the names of the above-listed copyright holders nor the names
     23  *    of any contributors may be used to endorse or promote products derived
     24  *    from this software without specific prior written permission.
     25  *
     26  * Alternatively, this software may be distributed under the terms of the
     27  * GNU General Public License ("GPL") version 2 as published by the Free
     28  * Software Foundation.
     29  *
     30  * NO WARRANTY
     31  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
     32  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
     33  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR
     34  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
     35  * HOLDERS OR CONTRIBUTORS BE LIABLE FOR SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     36  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     37  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     38  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
     39  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
     40  * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
     41  * POSSIBILITY OF SUCH DAMAGES.
     42  */
     43 
     44 #include "acpi.h"
     45 #include "accommon.h"
     46 #include "amlcode.h"
     47 #include "acparser.h"
     48 #include "acdebug.h"
     49 
     50 /*
     51  * This is an os-independent implementation of line-editing services needed
     52  * by the AcpiExec utility. It uses getchar() and putchar() and the existing
     53  * history support provided by the AML debugger. It assumes that the terminal
     54  * is in the correct line-editing mode such as raw and noecho. The OSL
     55  * interface AcpiOsInitialize should do this. AcpiOsTerminate should put the
     56  * terminal back into the original mode.
     57  */
     58 #define _COMPONENT          ACPI_OS_SERVICES
     59         ACPI_MODULE_NAME    ("acgetline")
     60 
     61 
     62 /* Local prototypes */
     63 
     64 static void
     65 AcpiAcClearLine (
     66     UINT32                  EndOfLine,
     67     UINT32                  CursorPosition);
     68 
     69 /* Various ASCII constants */
     70 
     71 #define _ASCII_NUL                  0
     72 #define _ASCII_BACKSPACE            0x08
     73 #define _ASCII_TAB                  0x09
     74 #define _ASCII_ESCAPE               0x1B
     75 #define _ASCII_SPACE                0x20
     76 #define _ASCII_LEFT_BRACKET         0x5B
     77 #define _ASCII_DEL                  0x7F
     78 #define _ASCII_UP_ARROW             'A'
     79 #define _ASCII_DOWN_ARROW           'B'
     80 #define _ASCII_RIGHT_ARROW          'C'
     81 #define _ASCII_LEFT_ARROW           'D'
     82 #define _ASCII_NEWLINE              '\n'
     83 
     84 extern UINT32               AcpiGbl_NextCmdNum;
     85 
     86 /* Erase a single character on the input command line */
     87 
     88 #define ACPI_CLEAR_CHAR() \
     89     putchar (_ASCII_BACKSPACE); \
     90     putchar (_ASCII_SPACE); \
     91     putchar (_ASCII_BACKSPACE);
     92 
     93 /* Backup cursor by Count positions */
     94 
     95 #define ACPI_BACKUP_CURSOR(i, Count) \
     96     for (i = 0; i < (Count); i++) \
     97         {putchar (_ASCII_BACKSPACE);}
     98 
     99 
    100 /******************************************************************************
    101  *
    102  * FUNCTION:    AcpiAcClearLine
    103  *
    104  * PARAMETERS:  EndOfLine           - Current end-of-line index
    105  *              CursorPosition      - Current cursor position within line
    106  *
    107  * RETURN:      None
    108  *
    109  * DESCRIPTION: Clear the entire command line the hard way, but probably the
    110  *              most portable.
    111  *
    112  *****************************************************************************/
    113 
    114 static void
    115 AcpiAcClearLine (
    116     UINT32                  EndOfLine,
    117     UINT32                  CursorPosition)
    118 {
    119     UINT32                  i;
    120 
    121 
    122     if (CursorPosition < EndOfLine)
    123     {
    124         /* Clear line from current position to end of line */
    125 
    126         for (i = 0; i < (EndOfLine - CursorPosition); i++)
    127         {
    128             putchar (' ');
    129         }
    130     }
    131 
    132     /* Clear the entire line */
    133 
    134     for (; EndOfLine > 0; EndOfLine--)
    135     {
    136         ACPI_CLEAR_CHAR ();
    137     }
    138 }
    139 
    140 
    141 /******************************************************************************
    142  *
    143  * FUNCTION:    AcpiOsGetLine
    144  *
    145  * PARAMETERS:  Buffer              - Where to return the command line
    146  *              BufferLength        - Maximum length of Buffer
    147  *              BytesRead           - Where the actual byte count is returned
    148  *
    149  * RETURN:      Status and actual bytes read
    150  *
    151  * DESCRIPTION: Get the next input line from the terminal. NOTE: terminal
    152  *              is expected to be in a mode that supports line-editing (raw,
    153  *              noecho). This function is intended to be very portable. Also,
    154  *              it uses the history support implemented in the AML debugger.
    155  *
    156  *****************************************************************************/
    157 
    158 ACPI_STATUS
    159 AcpiOsGetLine (
    160     char                    *Buffer,
    161     UINT32                  BufferLength,
    162     UINT32                  *BytesRead)
    163 {
    164     char                    *NextCommand;
    165     UINT32                  MaxCommandIndex = AcpiGbl_NextCmdNum - 1;
    166     UINT32                  CurrentCommandIndex = MaxCommandIndex;
    167     UINT32                  PreviousCommandIndex = MaxCommandIndex;
    168     int                     InputChar;
    169     UINT32                  CursorPosition = 0;
    170     UINT32                  EndOfLine = 0;
    171     UINT32                  i;
    172 
    173 
    174     /* Always clear the line buffer before we read a new line */
    175 
    176     memset (Buffer, 0, BufferLength);
    177 
    178     /*
    179      * This loop gets one character at a time (except for esc sequences)
    180      * until a newline or error is detected.
    181      *
    182      * Note: Don't attempt to write terminal control ESC sequences, even
    183      * though it makes certain things more difficult.
    184      */
    185     while (1)
    186     {
    187         if (EndOfLine >= (BufferLength - 1))
    188         {
    189             return (AE_BUFFER_OVERFLOW);
    190         }
    191 
    192         InputChar = getchar ();
    193         switch (InputChar)
    194         {
    195         default: /* This is the normal character case */
    196 
    197             /* Echo the character (at EOL) and copy it to the line buffer */
    198 
    199             if (EndOfLine == CursorPosition)
    200             {
    201                 putchar (InputChar);
    202                 Buffer[EndOfLine] = (char) InputChar;
    203 
    204                 EndOfLine++;
    205                 CursorPosition++;
    206                 Buffer[EndOfLine] = 0;
    207                 continue;
    208             }
    209 
    210             /* Insert character into the middle of the buffer */
    211 
    212             memmove (&Buffer[CursorPosition + 1], &Buffer[CursorPosition],
    213                 (EndOfLine - CursorPosition + 1));
    214 
    215             Buffer [CursorPosition] = (char) InputChar;
    216             Buffer [EndOfLine + 1] = 0;
    217 
    218             /* Display the new part of line starting at the new character */
    219 
    220             fprintf (stdout, "%s", &Buffer[CursorPosition]);
    221 
    222             /* Restore cursor */
    223 
    224             ACPI_BACKUP_CURSOR (i, EndOfLine - CursorPosition);
    225             CursorPosition++;
    226             EndOfLine++;
    227             continue;
    228 
    229         case _ASCII_DEL: /* Backspace key */
    230 
    231             if (!EndOfLine) /* Any characters on the command line? */
    232             {
    233                 continue;
    234             }
    235 
    236             if (EndOfLine == CursorPosition) /* Erase the final character */
    237             {
    238                 ACPI_CLEAR_CHAR ();
    239                 EndOfLine--;
    240                 CursorPosition--;
    241                 continue;
    242             }
    243 
    244             if (!CursorPosition) /* Do not backup beyond start of line */
    245             {
    246                 continue;
    247             }
    248 
    249             /* Remove the character from the line */
    250 
    251             memmove (&Buffer[CursorPosition - 1], &Buffer[CursorPosition],
    252                 (EndOfLine - CursorPosition + 1));
    253 
    254             /* Display the new part of line starting at the new character */
    255 
    256             putchar (_ASCII_BACKSPACE);
    257             fprintf (stdout, "%s ", &Buffer[CursorPosition - 1]);
    258 
    259             /* Restore cursor */
    260 
    261             ACPI_BACKUP_CURSOR (i, EndOfLine - CursorPosition + 1);
    262             EndOfLine--;
    263 
    264             if (CursorPosition > 0)
    265             {
    266                 CursorPosition--;
    267             }
    268             continue;
    269 
    270         case _ASCII_NEWLINE: /* Normal exit case at end of command line */
    271         case _ASCII_NUL:
    272 
    273             /* Return the number of bytes in the command line string */
    274 
    275             if (BytesRead)
    276             {
    277                 *BytesRead = EndOfLine;
    278             }
    279 
    280             /* Echo, terminate string buffer, and exit */
    281 
    282             putchar (InputChar);
    283             Buffer[EndOfLine] = 0;
    284             return (AE_OK);
    285 
    286         case _ASCII_TAB:
    287 
    288             /* Ignore */
    289 
    290             continue;
    291 
    292         case EOF:
    293 
    294             return (AE_ERROR);
    295 
    296         case _ASCII_ESCAPE:
    297 
    298             /* Check for escape sequences of the form "ESC[x" */
    299 
    300             InputChar = getchar ();
    301             if (InputChar != _ASCII_LEFT_BRACKET)
    302             {
    303                 continue; /* Ignore this ESC, does not have the '[' */
    304             }
    305 
    306             /* Get the code following the ESC [ */
    307 
    308             InputChar = getchar (); /* Backup one character */
    309             switch (InputChar)
    310             {
    311             case _ASCII_LEFT_ARROW:
    312 
    313                 if (CursorPosition > 0)
    314                 {
    315                     putchar (_ASCII_BACKSPACE);
    316                     CursorPosition--;
    317                 }
    318                 continue;
    319 
    320             case _ASCII_RIGHT_ARROW:
    321                 /*
    322                  * Move one character forward. Do this without sending
    323                  * ESC sequence to the terminal for max portability.
    324                  */
    325                 if (CursorPosition < EndOfLine)
    326                 {
    327                     /* Backup to start of line and print the entire line */
    328 
    329                     ACPI_BACKUP_CURSOR (i, CursorPosition);
    330                     fprintf (stdout, "%s", Buffer);
    331 
    332                     /* Backup to where the cursor should be */
    333 
    334                     CursorPosition++;
    335                     ACPI_BACKUP_CURSOR (i, EndOfLine - CursorPosition);
    336                 }
    337                 continue;
    338 
    339             case _ASCII_UP_ARROW:
    340 
    341                 /* If no commands available or at start of history list, ignore */
    342 
    343                 if (!CurrentCommandIndex)
    344                 {
    345                     continue;
    346                 }
    347 
    348                 /* Manage our up/down progress */
    349 
    350                 if (CurrentCommandIndex > PreviousCommandIndex)
    351                 {
    352                     CurrentCommandIndex = PreviousCommandIndex;
    353                 }
    354 
    355                 /* Get the historical command from the debugger */
    356 
    357                 NextCommand = AcpiDbGetHistoryByIndex (CurrentCommandIndex);
    358                 if (!NextCommand)
    359                 {
    360                     return (AE_ERROR);
    361                 }
    362 
    363                 /* Make this the active command and echo it */
    364 
    365                 AcpiAcClearLine (EndOfLine, CursorPosition);
    366                 strcpy (Buffer, NextCommand);
    367                 fprintf (stdout, "%s", Buffer);
    368                 EndOfLine = CursorPosition = strlen (Buffer);
    369 
    370                 PreviousCommandIndex = CurrentCommandIndex;
    371                 CurrentCommandIndex--;
    372                 continue;
    373 
    374             case _ASCII_DOWN_ARROW:
    375 
    376                 if (!MaxCommandIndex) /* Any commands available? */
    377                 {
    378                     continue;
    379                 }
    380 
    381                 /* Manage our up/down progress */
    382 
    383                 if (CurrentCommandIndex < PreviousCommandIndex)
    384                 {
    385                     CurrentCommandIndex = PreviousCommandIndex;
    386                 }
    387 
    388                 /* If we are the end of the history list, output a clear new line */
    389 
    390                 if ((CurrentCommandIndex + 1) > MaxCommandIndex)
    391                 {
    392                     AcpiAcClearLine (EndOfLine, CursorPosition);
    393                     EndOfLine = CursorPosition = 0;
    394                     PreviousCommandIndex = CurrentCommandIndex;
    395                     continue;
    396                 }
    397 
    398                 PreviousCommandIndex = CurrentCommandIndex;
    399                 CurrentCommandIndex++;
    400 
    401                  /* Get the historical command from the debugger */
    402 
    403                 NextCommand = AcpiDbGetHistoryByIndex (CurrentCommandIndex);
    404                 if (!NextCommand)
    405                 {
    406                     return (AE_ERROR);
    407                 }
    408 
    409                 /* Make this the active command and echo it */
    410 
    411                 AcpiAcClearLine (EndOfLine, CursorPosition);
    412                 strcpy (Buffer, NextCommand);
    413                 fprintf (stdout, "%s", Buffer);
    414                 EndOfLine = CursorPosition = strlen (Buffer);
    415                 continue;
    416 
    417             case 0x31:
    418             case 0x32:
    419             case 0x33:
    420             case 0x34:
    421             case 0x35:
    422             case 0x36:
    423                 /*
    424                  * Ignore the various keys like insert/delete/home/end, etc.
    425                  * But we must eat the final character of the ESC sequence.
    426                  */
    427                 InputChar = getchar ();
    428                 continue;
    429 
    430             default:
    431 
    432                 /* Ignore random escape sequences that we don't care about */
    433 
    434                 continue;
    435             }
    436             continue;
    437         }
    438     }
    439 }
    440