Editing Filename (section)

== {{anchor|6.3|8.3|18.3}}Length restrictions ==
Some filesystems restrict the length of filenames. In some cases, these lengths apply to the entire file name, as in 44 characters in IBM [[z/OS]].<ref name="44_char" /> In other cases, the length limits may apply to particular portions of the filename, such as the name of a file in a directory, or a directory name. For example, 9 (e.g., [[8-bit FAT]] in [[Standalone Disk BASIC]]), 11 (e.g. [[FAT12]], [[FAT16]], [[FAT32]] in DOS), 14 (e.g. early Unix), 21 ([[Human68K]]), 31<!--which OS?-->, 30 (e.g. [[Apple DOS]] 3.2 and 3.3), 15 (e.g. [[Apple ProDOS]]), 44 (e.g. IBM S/370),<ref name="44_char"/> or 255 (e.g. early Berkeley Unix) characters or bytes. Length limits often result from assigning fixed space in a filesystem to storing components of names, so increasing limits often requires an incompatible change, as well as reserving more space.

A particular issue with filesystems that store information in nested directories is that it may be possible to create a file with a complete pathname that exceeds implementation limits, since length checking may apply only to individual parts of the name rather than the entire name. Many Windows applications are limited to a <code>MAX_PATH</code> value of 260, but Windows file names can easily exceed this limit.<ref name="naming-files-paths-and-namespaces-windows">{{cite web|url=https://learn.microsoft.com/en-us/windows/win32/fileio/naming-a-file|title=Naming Files, Paths, and Namespaces|date=December 15, 2022|access-date=October 8, 2023}}</ref> From [[Windows 10 version history (version 1607)|Windows 10, version 1607]], MAX_PATH limitations have been removed.<ref>{{cite web|url=https://docs.microsoft.com/en-us/windows/win32/fileio/maximum-file-path-limitation|title=Maximum Path Length Limitation - Win32 apps|date=July 18, 2022 }}</ref>