PAGE 60,132 TITLE QUERY.COM VER.2.1 7-AUG-83 21:05 comment * QUERY.COM VERSION 2.1 6-AUG-83 Written by Warren Craycroft 6236 Oakdale Ave. Oakland, CA 94605 (C) 1983 by Warren Craycroft. Permission is granted to copy and distribute this program, including source code, provided that no charge shall be made except for a reasonable charge for the media and handling, and that this notice shall remain intact in all copies. * comment * This program is a utility that can be used with DOS 2.0 to allow a yes/no interaction by the user during execution of a batch file. The program does this by testing the user's one key response and returning to DOS an "errorlevel" code corresponding to that keycode response. This errorlevel code can then be tested by the batch file program using the IF ERRORLEVEL n statement. When QUERY is run in a batch file, an appropriate question has been posed to the user via a REM or ECHO statement, or the QUERY statment itself. A reverse video box then prompts. The user may answer with a single keystroke denoting a yes, no , or escape response. The errorlevel code is set as follows: errorlevel = 2 if user typed ESC key errorlevel = 1 if user typed Y or y errorlevel = 0 if user typed N or n If any other key is typed, the console is beeped,a message is displayed, and this program waits for another keystroke. Remember that the subsequent IF clauses are "greater than or equal to" and "less than", so the order of the IF tests is important. IF ERRORLEVEL N means if errorlevel >= n IF NOT ERRORLEVEL N means if errorlevel < n INCLUDE THESE FILES WHEN ASSEMBLING: PARSER.INC QDISPLAY.INC QGETKEY.INC Q_CMDS.INC * ; ; constant equates ; ESC_CHAR EQU 1BH ;ascii ESC keycode BEL_CHAR EQU 07 ;ascii BEL keycode CR EQU 0DH ;ascii carriage return LF EQU 0AH ;ascii line feed BLANK_CHAR EQU 20H ;ascii blank character ; ; equate the return codes to symbols so that this program can be ; easily modified to a different choice of returned errorlevel codes. ; ESC_RET_CODE EQU 2 Y_RET_CODE EQU 1 N_RET_CODE EQU 0 ; ; declare a relocatable segment. Follow the .COM file requirements ; of entry point at 100H and making all seg register references relative ; to CS (no relocatable values MOV'ed into segment registers). ; ; COM_CODE SEGMENT ; ORG 80H ;PSP offset 80: user's command line PSP_CMD_LINE LABEL BYTE ;define a label for address refs ; ORG 100H ;for COM file ; ; ASSUME CS:COM_CODE,DS:COM_CODE ;tell assembler value of CS ; and DS ; ; parse command line in PSP for commands inside slashes ; ; leave CX pointing to first character after leading delimiters if no ; slashes, or first char after second slash ; START PROC FAR ;FAR is meaningless; no RETS ; ; address of PSP's command line into SI ; MOV SI,OFFSET PSP_CMD_LINE ; INCLUDE PARSER.INC ;bring in parser include file INCLUDE QDISPLAY.INC ;bring in cmd line string display INCLUDE QGETKEY.INC ;bring in reverse prompt ; ; AL = user's answering keystroke. Test it for extended code ; OR AL,AL ;is the keycode zero? JNZ TEST_ESC ;jump if not, test for ESC MOV AH,1 ;else extended code was typed INT 21H ;get rest of code, then declare ;an error ; ; keycode was not one of the allowed codes. BEEP the console, ; display a message, and wait for another keycode from keyboard ; ERROR: MOV DX,OFFSET ERROR_MESSAGE ;display message string MOV AH,9 ;DOS fun code to display string INT 21H ;beep the console JMP DISPLAY_BOX ;and wait for another key ; ; test for ESC key, Y, y, N, n. Then exit (through DOS function 4CH) ; with appropriate exit code: ; ; exit code 2 if key was ESC ; ; exit code 0 if key was N or n ; ; exit code 1 if key was Y or y ; TEST_ESC: MOV DL,AL ;move keycode to DL MOV AL,ESC_RET_CODE ;return code for ESC MOV AH,4CH ;DOS fn call for exit ;(DOS Manual, p. D-49) ; CMP DL,ESC_CHAR ;is keycode ESC? JNE TEST_N ;jump if not, test for N ; ; Exit the program, returning to DOS via DOS 2.0 function call 4EH. ; This function call terminates execution of QUERY and sets the DOS ; "errorlevel" to the value found in AL. ; EXIT: INT 21H ;exit with return code in AL TEST_N: MOV AL,N_RET_CODE ;return code for N, n into AL CMP DL,'N' ;is it 'N'? JE EXIT ;jump if yes CMP DL,'n' ;is it 'n'? JE EXIT ;jump if yes and exit TEST_Y: MOV AL,Y_RET_CODE ;return code for Y, y into AL CMP DL,'Y' ;is keycode 'Y'? JE EXIT ;jump if yes and exit CMP DL,'y' ;else is keycode 'y'? JE EXIT ;jump if yes and exit JMP ERROR ;else beep the console and ;get another keycode START ENDP PAGE INCLUDE Q_CMDS.INC ;bring in slash command tables and code PAGE ; ; variable data area of the COM segment ; USERS_ATTRIB DB 1 DUP(?) ;temp storage of character attrib ; ; constant data area of the COM segment ; ERROR_MESSAGE DB CR,LF,BEL_CHAR DB ' *** Please press one of these keys only:' DB ' Y N Esc $' COM_CODE ENDS END START