Data file
What is a .o file?
A .o file is an Executable and Linkable Format (version 64bit Little Endian). This is a data file — structured information used by a program rather than read directly. Confusingly, this extension has been used by 5 different formats over the years — they're all listed below.
This extension has been used by more than one format
5 different formats have claimed .o over the years, so two files with the same extension aren't necessarily the same kind of thing.
- Executable and Linkable FormatVersion 64bit Little Endian · fmt/690
- Executable and Linkable FormatVersion 32bit Big Endian · fmt/689
- Linux/i386 Binary Executable File ZMAGICNo version recorded · fmt/1672
- Executable and Linkable FormatVersion 64bit Big Endian · fmt/691
- Executable and Linkable FormatVersion 32bit Little Endian · fmt/688
How to open a .o file
- Start with the program that produced it; that's almost always the right tool.
- Open it in a text editor to see whether it's readable text or binary.
- For database formats, DB Browser for SQLite or LibreOffice Base can often import it.
The registry records this extension against Executable and Linkable Format, Executable and Linkable Format, Linux/i386 Binary Executable File ZMAGIC and others, so software from that family is the most likely match.
How to convert a .o file
- If you can view the data, exporting to .csv is usually the most portable option.
The technical record
For archivists, developers and the merely curious: these are the PRONOM registry entries for .o.
| Format name | Version | MIME type | PUID |
|---|---|---|---|
| Executable and Linkable Format | 64bit Little Endian | — | fmt/690 |
| Executable and Linkable Format | 32bit Big Endian | — | fmt/689 |
| Linux/i386 Binary Executable File ZMAGIC | — | — | fmt/1672 |
| Executable and Linkable Format | 64bit Big Endian | — | fmt/691 |
| Executable and Linkable Format | 32bit Little Endian | — | fmt/688 |