Introduction

Language Structure

IB Statements

File System

Comet 32 Runtime

Index

Create DOS File

Syntax: DOSFC(AX-value, CX-value, file-name) EXCP=statement-label
Entry: 
  AX-value = "@3C00@"
  CX-value = "@0000@"
Return: 
  If the function call is successful, the AX field will contain the
  file's handle.

  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 create a DOS file. This call requires that the AX-value be set to "@3C00@", the CX-value to null, and the file-name to the name of the DOS file to be created (including disk and path name).

After the call is executed, the AX field will contain the file's handle. It is imperative that this value be stored for future use (i.e., for closing the file).

Example: 
  ! S SFCREATE,DSK
  ! O FCREATE,DSK
  ! L T00,E
  ! R QMONITOR
  !
  !==========  CREATE DOS FILE  ===================================
  !
  LENGTH 2 & LOCAL AX$,CX$                ! Define registers
  LENGTH 2 & LOCAL FILEHANDLE$            ! Define file handle
  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:"             ! Display prompt
  INPUT (0) FILENAME$                     ! Enter file name
  IF FILENAME$ = "" THEN RUN "QMONITOR"   ! If null, then stop
  FILENAME$ = FILENAME$ + "@00@"          ! Add null byte to name
  !
  AX$ = "@3C00@"                          ! Set AX to "CREATE FILE"
  CX$ = "@0000@"                          ! Set CX register to null
  !
  DOSFC(AX$,CX$,FILENAME$) EXCP=EXCEPTION ! Perform DOSFC call
  !
  FILEHANDLE$ = AX$                       ! Save file handle
  !
  PRINT (0) FILENAME$;" CREATED SUCCESSFULLY."
  PRINT (0) "FILE HANDLE IS:";FILEHANDLE$
  INPUT (0) ""
  RUN "QMONITOR"
  !
  EXCEPTION:                              ! Exception routine
  PRINT (0) "FILE NOT CREATED."           ! 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