How to open .TR files on Android
To open .TR files on Android, android typically cannot render troff/roff directly; open the .tr file in a text editor app to inspect it, then render it to PDF on a desktop system (e.g., with groff) and view the PDF on Android.
Step-by-step instructions
- Android typically cannot render troff/roff directly; open the .tr file in a text editor app to inspect it, then render it to PDF on a desktop system (e.g., with groff) and view the PDF on Android.
Common issues
The file opens as plain text with strange markup instead of a formatted document
.tr is commonly troff/roff source, so opening it in an editor shows formatting commands rather than the final laid-out result.
- Render the file with a troff formatter (such as GNU groff) to PDF/PS/text output and read the generated output.
- If you only need the raw content, keep using a text editor; the markup is expected.
Double-clicking does nothing or opens in the wrong app
Your system may not have a file association for troff/roff sources (or it may be mapped to a generic text type). Linux environments often use the shared-mime-info database to decide associations.
- Use “Open with” and select a text editor for editing, or your terminal and groff for rendering.
- On Linux, update or adjust MIME/file associations if needed (desktop environments consult the freedesktop.org shared-mime-info database).
Rendering fails or output looks wrong (missing macros/preprocessors)
Some troff/roff documents expect specific macro packages or preprocessor steps (as noted in the text/troff registration, which allows preprocessors before formatting).
- Try rendering with GNU groff and ensure required macro packages/preprocessors are included in your formatting command.
- If the .tr file came from a larger documentation project, obtain the accompanying macro files or build instructions used by the author.
Security note
A .tr file is typically plain text, but formatting tools still parse it; treat troff/roff input from untrusted sources cautiously because malformed input can trigger bugs in parsers/formatters.