VOLUME ATTRIBUTES

version 6.0

VOLUME ATTRIBUTES (volume; size; used; free)

The VOLUME ATTRIBUTES command returns, expressed in bytes, the size, the used space and the free space for the volume whose name you pass in volume.

Note: If volume indicates a non-mounted remote volume, the OK variable is set to 0 and the three parameters return -1.

Your application includes some batch operations running the night or the week-end that store huge temporary files on disk. To make this process as automatic and flexible as possible, you write a routine that will automatically find the first volume whose free space is sufficient for your temporary files. You might write the following project method:

      ` Find volume for space Project Method
      ` Find volume for space ( Real ) -> String
      ` Find volume for space ( Space needed in bytes ) -> Volume name or Empty string

   C_STRING(31;$0)
   C_STRING(255;$vsDocName)
   C_LONGINT($vlNbVolumes;$vlVolume)
   C_REAL($1;$vlSize;$vlUsed;$vlFree)
   C_TIME($vhDocRef)

      ` Initialize function result
   $0:=""
      ` Protect all I/O operations with an error interruption method
   ON ERR CALL("ERROR METHOD")
      ` Get the list of the volumes
   ARRAY STRING(31;$asVolumes;0)
   gError:=0
   VOLUME LIST($asVolumes)
   If (gError=0)
         ` If running on windows, skip the (usual) two floppy drives
      If (On Windows )
         $vlVolume:=Find in array($asVolumes;"A:\")
         If ($vlVolume>0)
            DELETE ELEMENT($asVolumes;$vlVolume)
         End if 
         $vlVolume:=Find in array($asVolumes;"B:\")
         If ($vlVolume>0)
            DELETE ELEMENT($asVolumes;$vlVolume)
         End if 
      End if 
      $vlNbVolumes:=Size of array($asVolumes)
         ` For each volume
      For ($vlVolume;1;$vlNbVolumes)
            ` Get the size, used space and free space    
         gError:=0
         VOLUME ATTRIBUTES($asVolumes{$vlVolume};$vlSize;$vlUsed;$vlFree)
         If (gError=0)
               ` Is the free space large enough (plus an extra 32K) ?
            If ($vlFree>=($1+32768))
                  ` If so, check if the volume is unlocked...        
               $vsDocName:=$asVolumes{$vlVolume}+Char(Directory symbol )+"XYZ"+String(Random)+".TXT"
               $vhDocRef:=Create document($vsDocName)
               If (OK=1)
                  CLOSE DOCUMENT($vhDocRef)
                  DELETE DOCUMENT($vsDocName)
                     ` If everything's fine, return the name of the volume
                  $0:=$asVolumes{$vlVolume}
                  $vlVolume:=$vlNbVolumes+1
               End if 
            End if 
         End if 
      End for 
   End if 
   ON ERR CALL("")

Once this project method is added to your application, you can for instance write:

   $vsVolume:=Find volume for space (100*1024*1024)
   If($vsVolume#"")
      ` Continue
   Else
      ALERT("A volume with at least 100 MB of free space is required!")
   End if

VOLUME LIST.