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