How Windows Generates 8.3 File Names from Long File Names
This article was previously published under Q142982
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Windows supports long file names up to 255 characters in length.Windows also generates an MS-DOS-compatible (short) file name in8.3 format to allow MS-DOS-based or 16-bit Windows-based programs toaccess the files.
Windows generates short file names from long file names in thefollowing manner:
- Windows deletes any invalid characters and spaces from the file name. Invalid characters include:. " / \ [ ] : ; = ,
- Because short file names can contain only one period (.), Windows removes additional periods from the file name if valid, non-space characters follow the final period in the file name. For example, Windows generates the short file name Thisis~1.txtfrom the long file nameThis is a really long filename.123.456.789.txtOtherwise, Windows ignores the final period and uses the next to the last period. For example, Windows generates the short file nameThisis~1.789from the long file nameThis is a really long filename.123.456.789.
- Windows truncates the file name, if necessary, to six characters and appends a tilde (~) and a digit. For example, each unique file name created ends with "~1." Duplicate file names end with "~2," "~3," and so on.
- Windows truncates the file name extension to three characters or less.
- Windows translates all characters in the file name and extension to uppercase.
For example, "Afile~1.doc" is generated from "A file.doc" because the longfile name contains a space.
No short file name is generated from "A_file.doc" because the file namecontains less than eight characters and does not contain a space.
The short file name "Alongf~1.txt" is generated from the long file name "Along filename.txt" because the long file name contains more than eightcharacters.
Article ID: 142982 - Last Review: 12/04/2015 13:06:46 - Revision: 1.3
Microsoft Windows Millennium Edition, Microsoft Windows 98 Standard Edition, Microsoft Windows 95, Microsoft Windows NT Server 4.0 Standard Edition, Microsoft Windows NT Workstation 4.0 Developer Edition
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