C/C++ Interactive Guide/c-cplusplus-interactive-guide.iso/c_ref/csource2/sclib_2/2_8/v6n8071a.txt

Text File | 1995-11-01 | 4.5 KB | 132 lines

    1: /*
    2:  * Listing 4:
    3:  *
    4:  * sc_admin.c - a server task to run resident on a PC,
    5:  * reading  the console and returning the data to a client
    6:  * task such as  the CVIEW program in listing 3.
    7:  */
    8:
    9: #include <stdio.h>
   10: #include <dev.h>
   11: #include <task_msgs.h>
   12: #include "sc_admin.h"  /* #defines for this application. */
   13:
   14: extern char Cmd_flags;  /* Defined in <magic.h> */
   15:
   16: my_seg()
   17: {
   18:   asm("  mov ax,ds");
   19: }
   20:
   21: main(argc,argv)
   22: int argc;
   23: char *argv[];
   24: {
   25:   register DISP_MSG *sbuffer;
   26:   register unsigned msg_size;
   27:   register int i;
   28:   int bytes, j;
   29:   unsigned rows, cols;
   30:   unsigned row_size;
   31:   unsigned max_size;
   32:   int tid;
   33:
   34:   /* Check for concurrent invocation. */
   35:   if (!(Cmd_flags & RUN_CONCURRENT))
   36:     error("This program cannot run by itself.\n");
   37:
   38:   /* Get size of current display window */
   39:   bytes = video_save_image(-1, 0, 0, 0, 0, 0);
   40:   i = video_get_size(-1);
   41:   rows = (i >> 8) & 0xff;
   42:   cols = i & 0xff;
   43:   row_size = cols * bytes;
   44:
   45:   /* Allocate enough space for message plus screen buffer */
   46:   max_size = sizeof(DISP_MSG) + ((rows + 1)* row_size);
   47:   sbuffer = (DISP_MSG *)calloc(1, max_size);
   48:
   49:   if (sbuffer == (DISP_MSG *)NULL)
   50:     error("Not enough memory to run.\n");
   51:
   52:   /* Loop forever */
   53:   while (TRUE) {
   54:
   55:     /*
   56:      * Receive messages from any client task.
   57:      * This task will block, consuming no CPU time
   58:      * if no client task is requesting data.
   59:      */
   60:     tid = receive(0, sbuffer, max_size);
   61:
   62:     /* Check for exception condition or failed receive */
   63:     /* If OK, process and reply to tid */
   64:     if (tid != -1 && tid != 0) {
   65:
   66:       switch (sbuffer->dtype) {
   67:
   68:         case GET_DSP_INFO :
   69:           sbuffer->dtype = OK;
   70:           sbuffer->drow = rows;
   71:           sbuffer->dcol = cols;
   72:           sbuffer->dbytes = bytes;
   73:           msg_size = sizeof(DISP_MSG);
   74:           break;
   75:
   76:         case GET_NXT_CHGS :
   77:           msg_size = sizeof(DISP_MSG) + row_size;
   78:           sbuffer->dbytes = bytes;
   79:           sbuffer->dtype = OK;
   80:           i = sbuffer->drow;
   81:           for (sbuffer->drow = -1; i < rows; i++) {
   82:             video_save_image( -1, i, 0,
   83:                               sbuffer->dbuffer, cols,
   84:                               my_seg());
   85:             if (memcmp( sbuffer->dbuffer,
   86:                         sbuffer->dbuffer +
   87:                         ((i + 1) * row_size),
   88:                         row_size))
   89:             {
   90:               for (j = sbuffer->dcol; j < cols; j++) {
   91:                 if (memcmp( sbuffer->dbuffer + (j * bytes),
   92:                             sbuffer->dbuffer +
   93:                             ((i + 1) * row_size)
   94:                             + (j * bytes), bytes))
   95:                   break;
   96:               }
   97:               memcpy( sbuffer->dbuffer +
   98:                       ((i + 1) * row_size),
   99:                       sbuffer->dbuffer, row_size);
  100:               sbuffer->drow = i;
  101:               sbuffer->dcol = j;
  102:               break;
  103:             }
  104:           }
  105:           break;
  106:
  107:         case GET_ALL_DATA :
  108:           for (i = 0; i < rows; i++)
  109:             video_save_image( -1, i, 0,
  110:                               sbuffer->dbuffer +
  111:                               ((i + 1) * row_size),
  112:                               cols, my_seg());
  113:           sbuffer->drow = rows;
  114:           sbuffer->dcol = cols;
  115:           sbuffer->dbytes = bytes;
  116:           sbuffer->dtype = OK;
  117:           msg_size = max_size;
  118:           break;
  119:
  120:         default :
  121:           sbuffer->dtype = NOT_OK;
  122:           msg_size = sizeof(DISP_MSG);
  123:           break;
  124:       }
  125:
  126:       /* Get video state (cursor position) of console */
  127:       video_get_state(-1, &sbuffer->dstate);
  128:       reply(tid, sbuffer, msg_size);
  129:     }
  130:   }
  131: }