Category : Files from Magazines
Archive   : PJ82.ZIP
Filename : FIG.4

/* excerpts from the Lex module for the Windows DDE Communications server. */

setdcb [sS][eE][tT][dD][cC][bB] /* only opcode we recognize */
integer [0-9]+
%{

extern LPSTR cmdstr; /* execute command string from client */

/* not interactive */
#undef YY_INTERACTIVE
#define YY_INTERACTIVE 0

/* this seems to allow lex to restart after seeing EOF */
#define YY_PRESERVE

/* define our own input */
#undef yygetc
#define yygetc() mygetc()

/* don't need this one */
#undef output
#define output(c)

/* take care of fatal errors a la windows */
#undef YY_FATAL
#define YY_FATAL(msg) { MessageBox(hWndMain, msg, szAppName, \
MB_OK | MB_ICONEXCLAMATION); \
PostMessage(hWndMain, WM_SYSCOMMAND, SC_CLOSE, 0L); }
%}

%%
{setdcb} {
return SETDCB;
}

{integer} {
yylval = atoi(yytext);
return INTEGER;
}

. {
return *yytext; /* let yacc handle any unexpected input */
}
%%

/* read the command string */
static int NEAR mygetc()
{
register ch = *cmdstr++;
return(ch ? ch : EOF);
}