Introduction MTB Statements File System Compiler Applications Reference Guide Index

Erase DOS File

Syntax: DOSFC(AX-value, CX-value, file-name) EXCP=statement-label
Entry: 
  AX-value = "@4100@"
  CX-value = "@0000@"
Return: 
  If an exception occurs, byte 2 of the AX field will contain the
  DOS error code (in hex).
Discussion: The DOSFC function call can be used to erase a DOS file. This function requires that the AX-value be set to "@4100@", the CX- value be set to null, and the file-name parameter be set to the name of the DOS file to be erased (including disk and path name).

After this function is executed, the file will be erased.

Example: 
  ! S SFERASE,DSK
  ! O FERASE,DSK
  ! L T00,E
  ! R QMONITOR
  !
  !==========  ERASE DOS FILE =====================================
  !
  LENGTH 2 & LOCAL AX$,CX$                ! Define registers
  LENGTH 64 & LOCAL FILENAME$             ! Define file name
  !
  LENGTH  3 & LOCAL DOSCODE$              ! Define DOS error code
  LENGTH 37 & LOCAL DOSMESSAGE$           ! Define DOS message
  !
  1000 FORMAT DOSMESSAGE$                 ! File input format
  !
  100 FORMAT (ET)                         ! Screen format
  !
  CLEAR                                   ! Initialize variables
  PRINT (0,100)                           ! Set typewriter mode
  !
  PRINT (0) "ENTER FILENAME TO ERASE:"    ! Display prompt
  INPUT (0) FILENAME$                     ! Enter file name
  IF FILENAME$ = "" THEN RUN "QMONITOR"   ! If null, then stop
  FILENAME$ = FILENAME$ + "@00@"          ! Add null byte to file 
  !
  AX$ = "@4100@"                          ! Set AX to "ERASE FILE"
  CX$ = "@0000@"                          ! Set CX register to null
  !
  DOSFC(AX$,CX$,FILENAME$) EXCP=EXCEPTION   ! Perform DOSFC call
  !
  PRINT (0) FILENAME$;" ERASED."
  INPUT (0) ""
  RUN "QMONITOR"
  !
  EXCEPTION:                              ! Exception routine
  PRINT (0) "FILE NOT ERASED."            ! Display message
  OPEN (1) "QERCOMET"                     ! Open error file
  DOSCODE$ = "D" + HEXASC(SUB(AX$,2,1))   ! Construct key to file
  READ (1,1000) KEY=DOSCODE$              ! Read error record
  PRINT (0) "DOS error code: ";DOSCODE$   ! Display DOS error code
  PRINT (0) DOSMESSAGE$                   ! Display error message
  INPUT (0) ""                            ! Hold
  CLOSE (1)                               ! Close error file
  RUN "QMONITOR"                          ! Exit
  END

DOS function calls/pseudo calls