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8.3 filename
An 8.3 filename (also called a short filename or SFN) is one that obeys the filename convention used by CP/M and old versions of DOS and versions of Microsoft Windows prior to Windows 95 and Windows NT 3.5. It is also used in modern Microsoft operating systems as an alternate filename to the long filename, to provide compatibility with legacy programs. The filename convention is limited by the FAT file system. Similar 8.3 (and 6.3) file naming schemes have also existed on earlier CP/M, TRS-80, Atari, and some Data General and Digital Equipment Corporation minicomputer operating systems.
8.3 filenames are limited to at most eight characters (after any directory specifier), followed optionally by a filename extension consisting of a period . and at most three further characters. For systems that only support 8.3 filenames, excess characters are ignored. If a file name has no extension, a trailing . has no significance (that is, myfile and myfile. are equivalent). Furthermore, file and directory names are uppercase in this system, even though systems that use the 8.3 standard are usually case-insensitive (making CamelCap.tpu equivalent to the name CAMELCAP.TPU). However, on non-8.3 operating systems (such as almost any modern operating system) accessing 8.3 file systems (including DOS-formatted floppy disks, but also including some modern memory cards and networked file systems), the underlying system may alter filenames internally to preserve case and avoid truncating letters in the names, for example in the case of VFAT.
VFAT, a variant of FAT with an extended directory format, was introduced in Windows 95 and Windows NT 3.5. It allowed mixed-case Unicode long filenames (LFNs) in addition to classic 8.3 names by using multiple 32-byte directory entry records for long filenames (in such a way that old 8.3 system software will only recognize one as the valid directory entry).
To maintain backward-compatibility with legacy applications (on DOS and Windows 3.1), on FAT and VFAT filesystems, the operating system automatically generates an 8.3 filename for every LFN, through which the file can [also] be opened, renamed, or deleted, although the generated name (e.g. OVI3KV~N) may show little similarity to the original. The generation of 8.3 filenames on NTFS filesystems can be turned off system-wide (with risks). The 8.3 filename can be obtained using the Kernel32.dll function GetShortPathName.
Although there is no compulsory algorithm for creating the 8.3 name from an LFN, Windows uses the following convention:
During the 2001 Microsoft antitrust case, the names MICROS~1 and MICROS~2 were humorously used to refer to the companies that might exist after a proposed split of Microsoft.
NTFS, a file system used by the Windows NT family, supports LFNs natively, but 8.3 names are still available for legacy applications. Windows NTVDM are known to use 8.3 names. This can optionally be disabled system-wide to improve performance in situations where large numbers of similarly named files exist in the same folder. 8.3 filename creation can be disabled system-wide and/or per-volume, and existing 8.3 filenames can be stripped using fsutil or a Registry key.
The ISO 9660 file system (mainly used on compact discs) has similar limitations at the most basic Level 1, with the additional restriction that directory names cannot contain extensions and that some characters (notably hyphens) are not allowed in filenames. Level 2 allows filenames of up to 31 characters, more compatible with classic AmigaOS and classic Mac OS filenames.
Hub AI
8.3 filename AI simulator
(@8.3 filename_simulator)
8.3 filename
An 8.3 filename (also called a short filename or SFN) is one that obeys the filename convention used by CP/M and old versions of DOS and versions of Microsoft Windows prior to Windows 95 and Windows NT 3.5. It is also used in modern Microsoft operating systems as an alternate filename to the long filename, to provide compatibility with legacy programs. The filename convention is limited by the FAT file system. Similar 8.3 (and 6.3) file naming schemes have also existed on earlier CP/M, TRS-80, Atari, and some Data General and Digital Equipment Corporation minicomputer operating systems.
8.3 filenames are limited to at most eight characters (after any directory specifier), followed optionally by a filename extension consisting of a period . and at most three further characters. For systems that only support 8.3 filenames, excess characters are ignored. If a file name has no extension, a trailing . has no significance (that is, myfile and myfile. are equivalent). Furthermore, file and directory names are uppercase in this system, even though systems that use the 8.3 standard are usually case-insensitive (making CamelCap.tpu equivalent to the name CAMELCAP.TPU). However, on non-8.3 operating systems (such as almost any modern operating system) accessing 8.3 file systems (including DOS-formatted floppy disks, but also including some modern memory cards and networked file systems), the underlying system may alter filenames internally to preserve case and avoid truncating letters in the names, for example in the case of VFAT.
VFAT, a variant of FAT with an extended directory format, was introduced in Windows 95 and Windows NT 3.5. It allowed mixed-case Unicode long filenames (LFNs) in addition to classic 8.3 names by using multiple 32-byte directory entry records for long filenames (in such a way that old 8.3 system software will only recognize one as the valid directory entry).
To maintain backward-compatibility with legacy applications (on DOS and Windows 3.1), on FAT and VFAT filesystems, the operating system automatically generates an 8.3 filename for every LFN, through which the file can [also] be opened, renamed, or deleted, although the generated name (e.g. OVI3KV~N) may show little similarity to the original. The generation of 8.3 filenames on NTFS filesystems can be turned off system-wide (with risks). The 8.3 filename can be obtained using the Kernel32.dll function GetShortPathName.
Although there is no compulsory algorithm for creating the 8.3 name from an LFN, Windows uses the following convention:
During the 2001 Microsoft antitrust case, the names MICROS~1 and MICROS~2 were humorously used to refer to the companies that might exist after a proposed split of Microsoft.
NTFS, a file system used by the Windows NT family, supports LFNs natively, but 8.3 names are still available for legacy applications. Windows NTVDM are known to use 8.3 names. This can optionally be disabled system-wide to improve performance in situations where large numbers of similarly named files exist in the same folder. 8.3 filename creation can be disabled system-wide and/or per-volume, and existing 8.3 filenames can be stripped using fsutil or a Registry key.
The ISO 9660 file system (mainly used on compact discs) has similar limitations at the most basic Level 1, with the additional restriction that directory names cannot contain extensions and that some characters (notably hyphens) are not allowed in filenames. Level 2 allows filenames of up to 31 characters, more compatible with classic AmigaOS and classic Mac OS filenames.