PRODUCT  :  Borland C++                           NUMBER  :  1030
  VERSION  :  3.x
       OS  :  DOS
     DATE  :  October 19, 1993                         PAGE  :  1/4

    TITLE  :  Using XFCBs to set/remove Volume Labels







    /* ------------------ [ SET VOLUME LABEL ] ----------------- *\
    | Finding the volume label of a particular Media can be       |
    | achieved with the findfirst() function of the Borland C/C++ |
    | compilers.   Modifying the Volume Label, however, requires  |
    | using Extended File Control Blocks.  The following function |
    | ( and Macros ) can be used to Set and Remove Volume Labels. |
    \* --------------------------------------------------------- */


  #include <mem.h>
  #include <dos.h>


  #pragma option -a-
  struct  EXTENDEDFCB
  {
      char    extSignature    ;
      char    extReserved1[5] ;
      char    extAttribute    ;
      char    extDriveID      ;
      char    extFileName[8]  ;
      char    extExtent[3]    ;
      short   extCurBlockNo   ;
      short   extRecSize      ;
      char    extFileSize[4]  ;
      short   extFileDate     ;
      short   extFileTime     ;
      char    extReserved2[8] ;
      char    extCurRecNo     ;
      char    extRandonRecNo[4];
  };
  #pragma option -a.




  /* -------------------- [ FCB MACROS ]----------------------- *\
  | The following MACROS take advantage of Borland C++'s         |
  | pseudoregisters and the __emit__() function to create a      |
  | wrapper around INT 21, FUNCTIONS 13H and 16H which allow for |













  PRODUCT  :  Borland C++                           NUMBER  :  1030
  VERSION  :  3.x
       OS  :  DOS
     DATE  :  October 19, 1993                         PAGE  :  2/4

    TITLE  :  Using XFCBs to set/remove Volume Labels.




  | the deletion and creation of FILES using FCBS.  The MACRO can|
  | be passed either an FCB or and Extended FCB structure with   |
  | the various fields already initialized.   The result of the  |
  | operation is kept in the AL register...                      |
  \* ---------------------------------------------------------- */
  #define CreateFCB( xfcb ) __emit__( 0x1E ); /* PUSH DS    */\
            _AH = 0x2F;             /* Get Current DTA      */\
            geninterrupt( 0x21 );   /* Call Upon DOS..      */\
            __emit__( 0x06, 0x53 ); /* PUSH ES - PUSH BX    */\
            _DS = FP_SEG( &xfcb );  /* Load Seg. of New DTA */\
            _DX = FP_OFF( &xfcb );  /* Load Off. of New DTA */\
            _AH = 0x1A;             /* Set DTA Function..   */\
            geninterrupt( 0x21 );   /* Call Upon DOS        */\
            _AH = 0x16;             /* Create File Function */\
            geninterrupt( 0x21 );   /* Call Upon DOS        */\
            __emit__( 0x5A, 0x1F ); /* POP DX  - POP  DS    */\
            __emit__( 0x50 );       /* PUSH AX ( results )  */\
            _AH = 0x1A;             /* Set ( Restore ) DTA  */\
            geninterrupt( 0x21 );   /* Call Upon DOS        */\
            __emit__( 0x58 );       /* Restore Results...   */\
            __emit__( 0x1F );       /* Restore DS value...  */

  #define DeleteFCB( xfcb )  __emit__( 0x1E ); /* PUSH DS   */\
            _AH = 0x2F;             /* Get Current DTA      */\
            geninterrupt( 0x21 );   /* Call Upon DOS..      */\
            __emit__( 0x06, 0x53 ); /* PUSH ES - PUSH BX    */\
            _DS = FP_SEG( &xfcb );  /* Load Seg. of New DTA */\
            _DX = FP_OFF( &xfcb );  /* Load Off. of New DTA */\
            _AH = 0x1A;             /* Set DTA Function..   */\
            geninterrupt( 0x21 );   /* Call Upon DOS        */\
            _AH = 0x13;             /* Delete File Function */\
            geninterrupt( 0x21 );   /* Call Upon DOS        */\
            __emit__( 0x5A, 0x1F ); /* POP DX  - POP  DS    */\
            __emit__( 0x50 );       /* PUSH AX ( results )  */\
            _AH = 0x1A;             /* Set ( Restore ) DTA  */\
            geninterrupt( 0x21 );   /* Call Upon DOS        */\
            __emit__( 0x58 );       /* Restore Results...   */\
            __emit__( 0x1F );       /* Restore DS value...  */




  /* --------------- [ SET VOLUME LABEL ]--------------------- *\













  PRODUCT  :  Borland C++                           NUMBER  :  1030
  VERSION  :  3.x
       OS  :  DOS
     DATE  :  October 19, 1993                         PAGE  :  3/4

    TITLE  :  Using XFCBs to set/remove Volume Labels.




  |  This function modifies the VOLUME LABEL of the specified   |
  |  Drive using extended FCBs.  The parameters are as follows: |
  |  driveNum:   0 for current, 1 for A:, 2 for B:, 3 for C: etc|
  |  Label   :   ASCIIZ string containing new label ( If NULL   |
  |              current label is merely removed ).             |
  |  RETURNS :   0x00-Successful                 0xFF-Failed    |
  \* --------------------------------------------------------- */
  int SetVolLabel( int driveNum, char *Label )
  {
      char *p;
      struct EXTENDEDFCB  xfcb;

      memset(( void * )&xfcb, 0x20, sizeof( xfcb ));

      xfcb.extSignature = 0xFF;   /* Signal Extended FCB */
      xfcb.extAttribute = 0x08;   /* Volume's Attribute  */
      xfcb.extDriveID   = ( char )driveNum;  /* Drive ID.*/

      memset(( void * )xfcb.extFileName, '?', 11 );
      DeleteFCB( xfcb );          /* Delete any LABEL    */

      if ( !Label )               /* NULL Label ?        */
          return(( int )_AL );    /* Just return if YES..*/

      memset(( void * )xfcb.extFileName, ' ', 11 );
      for( p = xfcb.extFileName;
           p < ( char * )&xfcb.extCurBlockNo;
           p++ )
      {
          if ( *Label == NULL )
              break;
          *p = *Label++;
      }
      CreateFCB( xfcb );          /* Create New Label..  */
      return(( int )_AL );        /* Return Results..    */
  }




  int main( int argc, char *argv[] )
  {
      if ( argc > 1 )













  PRODUCT  :  Borland C++                           NUMBER  :  1030
  VERSION  :  3.x
       OS  :  DOS
     DATE  :  October 19, 1993                         PAGE  :  4/4

    TITLE  :  Using XFCBs to set/remove Volume Labels.




          SetVolLabel( 0, argv[1] ); /* Set Label of Local  */
      else
          SetVolLabel( 0, NULL );    /* Clear Label of Local*/
      return( 0 );
  }