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     [[DosOpen]]
     [[DosOpen]]
     [[DosOpenL]]
     [[DosOpenL]]
     [[DosPerfSysCall]]
     [[DosPerfSysCall|DosPerfSystemCall]] *
     [[DosProtectOpenL]]
     [[DosProtectOpenL]]
     [[DosProtectQueryFileInfo]]
     [[DosProtectQueryFileInfo]]
     [[DosProtectSetFileInfo]]
     [[DosProtectSetFileInfo]]
     [[DosProtectSetFileLocksL]]
     [[DosProtectSetFileLocksL]]
     [[DosProtectSetFilePrtL]]
     [[DosProtectSetFilePtrL]]*
     [[DosProtectSetFileSizeL]]
     [[DosProtectSetFileSizeL]]
     [[DosQueryABIOSSuport]]
     [[DosQueryABIOSSuport]]

Revision as of 03:38, 16 May 2025

Programming Guide and Reference Addendum
  1. About this book
  2. DosDebug Commands
  3. Device Helper (DevHlp) Services and Function Codes
  4. Control Program Functions
  5. Raw File System APIs
  6. IOCtls
  7. Network APIs
  8. Windows Functions
  9. APIs Supporting High Memory Objects
  10. Notices

Reprint Courtesy of International Business Machines Corporation, © International Business Machines Corporation

This chapter contains an alphabetic list of the following Control Program functions:

   DosAliasMem
   DosCancelLockRequestL
   DosClose
   DosCreateEventSem
   DosCreateThread2
   DosDumpProcess
   DosFindFirst
   DosFindNext
   DosForceSystemDump
   DosGetProcessorStatus
   DosListIO
   DosListIOL
   DosOpen
   DosOpenL
   DosPerfSystemCall *
   DosProtectOpenL
   DosProtectQueryFileInfo
   DosProtectSetFileInfo
   DosProtectSetFileLocksL
   DosProtectSetFilePtrL*
   DosProtectSetFileSizeL
   DosQueryABIOSSuport
   DosQueryFileInfo
   DosQueryMemState
   Dos16QueryModFromCS
   DosQueryModFromEIP
   DosQueryPathInfo
   DosQuerySysInfo
   DosQuerySysState
   DosQueryThreadAffinity
   DosRead
   DosReplaceModule
   DosSetFileInfo
   DosSetFileLocksL
   DosSetFilePtr
   DosSetFilePtrL
   DosSetFileSizeL
   DosSetPathInfo
   DosSetProcessorStatus
   DosSetThreadAffinity
   Dos16SysTrace
   DosTmrQueryFreq
   DosTmrQueryTime
   DosVerifyPidTid
   DosWrite

The following APIs, from the list above, are Raw File System APIs:

   DosClose
   DosListIO
   DosOpen
   DosRead
   DosSetFilePtr
   DosWrite

The OS/2 raw file system provides an interface for applications to manage data efficiently on the logical partitions or physical hard drives installed in a system. Some of the raw file system function is available by using a combination of the DosPhysicalDisk and DosDevIOCtl application programming interfaces.

The OS/2 raw file system provides a programming abstraction that treats each logical partition or physical disk as one large file that can be opened, locked, seeked, read from, written to, and closed. Logical partitions are identified using the Universal Naming Convention (UNC) in the form of '\.\X', where 'X' can be substituted with the letter corresponding to the logical partition desired on any hard drive, floppy disk or CD-ROM drive. Physical disks are identified using UNC naming in the form of '\.\Physical_Disk#', where '#' is replaced with the physical disk number corresponding to the number found in the LVM command. The combination of the naming convention and use of the common file system application programming interfaces (APIs) provides a greatly simplified migration path for applications.

Traditionally, raw file systems have been utilized by applications that manage large amounts of data under heavy workloads. Typically, this has been commercial database servers performing on-line transaction processing. Disk I/O can become a bottleneck under these conditions and the use of an efficient raw file system can be very useful in improving system performance, through reduced path length and serialization.