Long File Name (LFN) compatible programs for DOS

MS-DOS 7.10 and ROM-DOS 7.10 are two examples of modern DOS systems. Besides FAT32 and large disk (LBA) support, they support two types of file names: the traditional 8.3 short file names (SFN), and the modern long file names (LFN). In the old 8.3 SFN, a file name can only have 8 characters at most, plus a file extension with a maximum of 3 characters. On the other hand, in the modern LFN, a file name may have up to 255 characters including spaces, much longer than the traditional 8.3 file format. In order to keep compatibility with existing programs, each LFN has an associated 8.3 SFN. For example, "Program Files" in LFN becomes "PROGRA~1" in SFN.

Nowadays, most operating systems or platforms (such as Windows 9x/Me/NT3.51/NT4/2K/XP+) are capable of LFN,  since LFN is clearly much more flexible and useful than the old 8.3 SFN in most cases. MS-DOS 7.10 is an LFN compatible DOS, yet it will not be able to access LFN directly without the presence of LFN API (API stands for Application Programming Interface). By default, the DOS LFN API support is enabled after the MS-DOS 7.10 Setup. This means you can use either SFN or LFN, or both natively in MS-DOS 7.10 after installation. For example, if you type "DIR" in MS-DOS 7.10, both SFN and LFN of the files will be displayed on the screen (SFN on the left side, and LFN on the right side). Like files, LFN applies to directory names too. If you want to enter a directory containing spaces in the DOS command line, simply add quotation marks around the LFN name, e.g. CD "C:\Program Files" (or use its associated SFN name: CD PROGRA~1). More information and resources about MS-DOS 7.10 can be found from this page.

Besides real DOS systems, there are currently two leading DOS emulators running cross-platform or on the Windows platform, namely DOSBox and vDos. However, original versions of them do not support long file names. Fortunately, I was able to add long file name support and other features to both of these DOS emulators. The versions of them with LFN (and other features) enabled are known as DOSBox SVN-lfn and vDosPlus (initially known as vDos-lfn) respectively, both of them have LFN API included and enabled by default. Like MS-DOS 7.10, they support both the traditional 8.3 names (SFNs) and the long file names (LFNs). Some information about their LFN support can be found in this support page.

Despite the fact that LFNs and SFNs are supported natively by modern DOS systems such as MS-DOS 7.10 as well as both DOSBox-X/SVN-lfn and vDosPlus, however, since most older versions of DOS could only support the traditional 8.3 SFN, the majority of existing DOS programs and utilities are only compatible with SFNs, but not LFNs. Unlike MS-DOS 7.10, older versions of DOS (e.g. MS-DOS 6.x) and DOS programs are unaware of LFN, even if the LFN API is present. Older disk utilities, such as Speed Disk from Norton Utilities 8.0 and DEFRAG from MS-DOS 6.x, will destroy the LFN entries during their operations. Even a simple rename or copy command in MS-DOS 6.x could cause problems with LFN (the associated LFNs will be lost, and the garbage entries will appear in the file system). On the other hand, MS-DOS 7.10 will be able to handle this smoothly, regardless of whether or not LFN API is present. When there is LFN API, MS-DOS 7.10 will be able to use or handle it natively; when no LFN API present, LFN entries in MS-DOS 7.10 will be preserved or removed safely rather than broken (as in MS-DOS 6.x) after a related file or disk operation.

Therefore, as LFNs are used more and more frequently at the present time, we should avoid using those older and outdated versions of DOS and DOS programs which are incompatible or may cause problems with LFNs whenever possible. I have made an incomplete list of useful DOS programs that are compatible with LFNs (see below), also known as LFN-aware applications, which will work with LFNs directly in an LFN-enabled environment such as MS-DOS 7.10 Full Version with LFN support.

List of some useful LFN compatible programs for DOS:

Part I: DJGPP programs

DJGPP is a complete 32-bit C/C++ development system for 386+ PCs running DOS. One of the main features is that it and most of its compiled programs are completely compatible with LFN. Because of its features, functionality and ease of use, an increasing number of modern DOS programs are compiled by DJGPP, namely, the DJGPP programs. For the time being, a large part of DOS LFN-aware programs are in fact DJGPP programs. Note that they are all 32-bit protected mode DOS programs which require a DPMI provider (e.g. CWSDPMI.EXE or HDPMI32.EXE). Examples:

Part II: Non-DJGPP programs

Of course, there are also a plenty of DOS LFN-aware programs that are not compiled by DJGPP and are compatible with LFNs. These programs can be either real-mode DOS programs or protected mode DOS programs. Examples:

Part III: Win32 applications under DOS (via HX DOS Extender)

Since it is possible to launch most Win32 console applications and some Win32 GUI applications under pure DOS using HX DOS Extender, and HX DOS Extender fully supports long file names whenever available and will provide LFN APIs to all compatible Win32 applications, this adds a wide range of applications that can be run under DOS and are LFN compatible; in most cases you can simply load HXLDR32.EXE from HX DOS Extender once and then run any compatible Win32 applications you want in real DOS as if they are native DOS applications. Examples:

Name	Description	Comment
7-Zip	A modern file compressor/decompressor	With very high compression ratio
ARJ32	A file compressor/decompressor
B-Zip2	A pack utility from MSYS	Common in Unix-like systems
CABARC	A cabinet file management tool	Powerful CAB manager from Microsoft
MAKECAB	A cabinet file creation tool
DAO	A CD Disc At Once write tool	A set of powerful CD tools from Golden Hawk
DOSBox-X	A PC and DOS emulator	Official DOS version is available; run with "DOSBOX-X -SET LFN=1" to enable LFN support
DOSBox SVN-lfn	A PC and DOS emulator	It can be run from DOS itself, with LFN support; load the MinGW version with "DPMILD32 -g dosbox"
FTP	A FTP client from MSYS
GZip	A pack utility from MSYS	Common in Unix-like systems
Java	The Java compiler and most Java console applications	Very useful
KZIP	A PKZIP clone
MinGW	GNU GCC C++/G77 Fortran compiler, AS assembler	Very useful
MASM32	Microsoft 32-bit assembler
MPlayer	A video player supporting most multimedia formats	With very versatile multimedia support
NASM	Netwide Assembler
PKZIPC	A 32-bit ZIP packer/unpacker
PNGOUT	A PNG file size optimizer
PictView32	An image converter	It supports many image formats
PSFTP	A SFTP client
TASM32	Borland 32-bit assembler
Telnet	A Telnet client from MSYS
VIM	A file editor from MSYS	Common in Unix-like systems
XCOPY32	Win9x 32-bit console file copy program	Created with "PESTUB XCOPY32.MOD"
And other Win32 applications compatible with HX DOS Extender

Part IV: Disk utilities

Unlike the old disk utilities, such as the ones from MS-DOS 6.x, most newer versions of disk utilities will work fine with LFN. Although a lot of them only display SFN instead of LFN while running in pure DOS, they are still LFN compatible, which means they are LFN aware and will not destroy LFN. Besides the ones (e.g. SCANDISK) from MS-DOS 7.10, there are quite a large number of disk utilities with LFN support for DOS. Examples:

The list is not yet complete. But it should be now clear there are quite a number of LFN compatible programs for DOS.

Any questions, problems, or suggestions, please feel free to mail me!

Last updated: January 2021, Wengier