Windows File Name Legal Characters

When you create Internet shortcuts in Windows, invalid characters are ignored to create the file name, except for the forward slash, which is converted to minus. For file I/O, the „?“ prefix of a path string tells the Windows APIs to disable all string parsing and send the next string directly to the file system. For example, if your file system supports large file names and paths, you can exceed the MAX_PATH limits otherwise enforced by the Windows APIs. For more information about the normal maximum path limit, see the previous section, Maximum Path Length Restriction. There is no guarantee that the array returned by this method will contain the full set of invalid characters in the file and directory names. The full set of invalid characters may vary depending on the file system. Unix-like file systems allow a file to have more than one name. In traditional Unix file systems, names are hard links to the inode or file equivalent. Windows supports hard links on NTFS file systems and provides the fsutil command for authoring in Windows XP and mklink in later versions. [4] [5] In-hard links are different from Windows shortcuts, classic Mac OS/macOS aliases, or symbolic links.

The introduction of LFN with file name aliases allowed by VFAT. Example: longfi ~ 1,??? With a maximum of eight characters plus three, a filename alias of „Long File Name.???“ was a way to comply with 8.3 restrictions for older programs. Traditionally, filenames allowed any character in their filenames as long as they were safe for the file system. [2] Although this allowed the use of any encoding and thus the representation of local text on any local system, it caused many interoperability issues. On early personal computers that used the CP/M operating system with the File Allocation Table (FAT) file system, file names were still 11 characters. This is called an 8.3 filename with a maximum of an 8-byte name and a maximum of a 3-byte extension. Utilities and applications allowed users to specify file names without trailing spaces and insert a period before the extension. The point was not actually stored in the directory. Using only 7-bit characters, multiple file attributes [1] can be included in the actual file name using the high-order bit. These attributes included Read Only, Archive, Hidden, and SYS. In the end, this was too restrictive and the number of characters allowed increased.

The attribute bits have been moved to a special block in the file with additional information. This has led to compatibility issues when moving files between different file systems. [2] An absolute reference includes all directory levels. By default, some systems use the current working directory as the file name reference, which does not contain the full path to the directory. This is a relative reference. One of the advantages of using a relative reference in program configuration files or scripts is that different instances of the script or program can use different files. On Linux, this means that the file name is not sufficient to open a file: In addition, the exact representation in bytes of the file name on the storage device is required. This can be resolved at the application level with tricky normalization calls. [8] Some people use the term filename when referring to a complete specification of devices, subdirectories, and file names, such as Windows C:Program FilesMicrosoft GamesChessChess.exe. The file name in this case is Chess.exe. Some utilities have settings to remove the extension as in MS Windows Explorer. There are also APIs that allow the use of the NT namespace convention, but the Windows Object Manager makes this unnecessary in most cases.

As an illustration, it is useful to browse the Windows namespaces in System Object Explorer by using the Windows Sysinternals WinObj tool. When you run this tool, you will see the NT namespace that starts at the root directory, or „“. The Win32 namespace is located in the Global subfolder??. Named device objects are located in the NT namespace of the Device subdirectory. You will also find Serial0 and Serial1, the device objects that represent the first two COM ports, if they are present on your system. For example, a device object that represents a volume would be HarddiskVolume1, although the numeric suffix may vary. The name DR0 in the Harddisk0 subdirectory is an example of a device object that represents a hard disk, and so on. Here is a C# implementation for Windows based on Christopher Oezbek`s response Character count restrictions may also vary depending on the file system and path prefix format used. This is further complicated by support for backward compatibility mechanisms.

For example, the older MS-DOS FAT file system supports a maximum of 8 characters for the base file name and 3 characters for the extension, for a total of 12 characters, including the period separator. This is commonly referred to as the 8.3 file name. The Windows FAT and NTFS file systems are not limited to 8.3 file names because they support long file names, but they still support 8.3 long file names. If you try to upload a file with an invalid file name or type, you receive the following error message along with an indicator to the right of your file. As a test, I formed a file name with all these characters and Windows accepted it. The URL is old. The new document URL is now If your data comes from a source that allows non-printing characters, there`s still a lot to check. Do not end a file or directory name with a space or period. Although the underlying file system supports such names, this is not the case in the Windows shell and user interface. However, it is acceptable to specify a period as the first character of a name. For example, „.temp“.

If you are using Windows API functions, you must use the „.“ prefix to access only devices, not files. Some file systems, such as FAT, store file names in uppercase, regardless of the case used to create them. For example, a file created with the name MyName.txt or MyName.txt is saved with the file name MyName.TXT. Any case variation can be used to refer to the same file. These types of file systems are case-insensitive and case-insensitive. Some file systems completely prohibit the use of lowercase letters in file names. There are two main categories of namespace conventions used in Windows APIs, commonly referred to as NT namespaces and Win32 namespaces. The NT namespace was designed as the lowest namespace on which other subsystems and namespaces could exist, including the Win32 subsystem, and thus the Win32 namespaces. POSIX is another example of a subsystem in Windows built on the NT namespace. Early versions of Windows also defined several predefined or reserved names for specific devices such as communication ports (serial and parallel) and the default display console as part of the current NT device namespace, and are still supported in current versions of Windows for backward compatibility. „Qualified“.

after 8 characters or less. [23] Partitioned records (PDS or PDSE) are divided into members whose names cannot exceed 8 characters; the member`s name is placed in parentheses after the PDS name, e.g. PAYROLL. DEV. CBL(PROG001) The path to a specified file consists of one or more components separated by a special character (backslash), each component usually being a directory name or file name, but with some notable exceptions discussed below. For the system`s interpretation of a path, it is often crucial to know what the beginning or prefix of the path looks like. This prefix determines the namespace used by the path and, in addition, which special characters are used in which location in the path, including the last character. Note: Although it is legal on Linux/Unix file systems to create files with control characters in the file name, it can be a nightmare for users to process such files.

Note: This list is not exhaustive. It is designed to help you avoid common errors in file names. If you have any questions or need help, don`t hesitate to A file name can be stored with different byte strings in different systems within a country, for example when using Japanese JIS Shift encoding and other Japanese EUC encoding. The conversion was not possible because most systems did not provide a description of the encoding used for a file name as part of the extended file information. This forced expensive file name encodings every time a file was accessed. [2] Data can be accessed from hard drives, devices, and network shares using file I/O APIs. Files and directories, as well as namespaces, are part of the path concept, which is a string representation that specifies where to retrieve data, whether it comes from a disk, device, or network connection for a particular operation. Note that the directory must contain entries.

and .., so there were probably 253 files (and 2 directories) or 255 name entries instead of 254 files. This does not affect the effectiveness of the anecdote or the careful tests it describes. In editions of Windows earlier than Windows 10, version 1607, the maximum length of a path is MAX_PATH, which is set to 260 characters. In later versions of Windows, changing a registry key or using the Group Policy tool is required to remove the limit. For more information, see Maximum Path Length Limit. A filename (depending on the file system) may include: Other people covered the rules for Windows filenames, with links to Microsoft and Wikipedia on the subject. Supported characters for a file name are letters, numbers, spaces, and ( ) _ – ,. If you receive the error message, you must delete all unsupported file types and/or rename the file with a valid file name (remove all unsupported special characters), and then upload the renamed document. If you need to keep the storage naming convention, you can temporarily rename the file you want to download and edit it again after sending the fax.