FORMAT (OS/2 command)
| Company type | Command-line utility |
|---|---|
| Industry | Computing / Software |
| Founded | 1981 |
| Headquarters | N/A |
| Products | Disk formatting tool |
In computing, format refers to a command-line tool used for preparing storage media by formatting disks. This utility is incorporated into a variety of operating systems, including 86-DOS, MS-DOS, IBM PC DOS, OS/2, Microsoft Windows, and ReactOS.
Overview
The format command is primarily utilized to prepare floppy disks, hard drives, solid-state drives (such as USB flash drives), and other magnetic storage devices—excluding optical discs—by performing the following actions:
- Resetting the FAT entries to
- Clearing the FAT root directory by setting entries to
- Scanning clusters to detect and differentiate between usable and defective sectors within the FAT
Through this procedure, the storage device is organized to establish a functional filesystem. Comparable commands are available on Unix, Linux, and BSD platforms for creating various filesystem formats compatible with DOS, Windows, and OS/2 environments.
Implementations
This command exists across numerous operating systems, including Intel ISIS-II, iRMX 86, MetaComCo TRIPOS, AmigaDOS, Zilog Z80-RIO, Microware OS-9, DR FlexOS, TSL PC-MOS, SpartaDOS X, Datalight ROM-DOS, IBM/Toshiba’s 4690 OS, PTS-DOS, SISNE plus, and the DEC RT-11 system.
Microsoft DOS and Windows
The format command has been included with MS-DOS starting from its initial release.
When used with the /S ("system") option, format installs a Volume Boot Record by writing bootstrap code into the first sector. Regardless of whether /S is specified, it always writes a BIOS Parameter Block at that location.
Activating the /Q switch triggers a "Quick Format," which bypasses some steps and leaves existing data on the media intact.
In MS-DOS versions 3.2 and earlier, entering "format" without additional parameters would automatically format the current drive; beginning with MS-DOS 3.3, omitting parameters results in an error message.
DR/Novell DOS
DR DOS 6.0 features its proprietary version of the format command.
FreeDOS
The FreeDOS implementation of format was created by Brian E. Reifsnyder and is distributed under the terms of the GPL.
ReactOS
ReactOS’s format command originates from a free clone developed by Mark Russinovich for Sysinternals in 1998 under the GPL license. Emanuele Aliberti adapted this version for ReactOS in 1999. It supports filesystems such as FAT, FAT32, FATX, EXT2, and BtrFS.
See also
- Disk formatting
- Data recovery
- convert
- File Allocation Table
- Design of the FAT file system
- fdisk
- PC DOS 7.10 Format32
Notes
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Additional resources
Related links
- Official Microsoft Windows XP Professional Documentation: "format"
- Source code for FORMAT from MS-DOS version 2.0
- Microsoft Knowledge Base article 255867: Guidance on using Fdisk and Format for disk partitioning
- Overview of the Microsoft DOS format command
- Details on the Recovery Console format command