How to open .CU files on Linux
To open .CU files on Linux, open the .cu file with a code editor (or any text editor) to inspect it as source code.
Step-by-step instructions
- Open the .cu file with a code editor (or any text editor) to inspect it as source code.
- If your desktop shows it as “CU-SeeMe” due to MIME mapping, explicitly choose “Open With Text Editor” (the content is what matters, not the label).
- To compile, use your project’s build process with the CUDA toolchain.
Recommended software
- VS Code
- Notepad++/TextEdit
- jq (CLI)
Alternative methods
- Open .CU in a browser-based viewer if desktop apps fail.
- Try opening .CU on Linux with a secondary app to rule out app-specific issues.
- Convert .CU only with trusted tools when direct opening is not possible.
Common issues
The file is identified as “CU-SeeMe” or opens in the wrong app
Some systems map .cu to the MIME type application/cu-seeme, which can lead to misleading “Open with” suggestions and icons.
- Ignore the label and open the file with a plain text/code editor to confirm whether it contains CUDA C/C++ source.
- On Linux desktops, consider adjusting file associations so .cu opens in your editor by default (association changes affect convenience, not the file format).
Double-clicking doesn’t “run” the file
.cu is typically source code, not an executable document; it must be compiled (usually as part of a project).
- Open the file in a code editor/IDE and locate the project/build instructions (README, build scripts, or IDE configuration).
- Compile using the CUDA toolchain as intended by the project rather than trying to execute the .cu file directly.
The .cu file looks unreadable or binary
Not every file named .cu is guaranteed to be CUDA source; it may be misnamed, corrupted, or from another workflow.
- Verify the source of the file (project repository, sender, or download) and re-download if it may be incomplete.
- Check whether the content is plain text; if it is not, ask for the correct file or documentation describing what the file should contain.
Security note
.cu files are usually plain-text source code, but they can still be risky: building or running code from untrusted sources can execute malicious behavior during compilation scripts or when you run the resulting program.