Editing and saving
Text editing, encoding changes, atomic saves and backups, and the hex editor for large files.
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SigXor is not only a viewer: it can edit text and binary content directly. Every save goes through a temporary file and an atomic replace, and a backup is written first.
Text editing#
Switch to edit mode from the text or code preview toolbar:
- Edit, undo (Ctrl + Z) and redo (Ctrl + Y).
- A dirty marker shows unsaved changes.
- Change the encoding and save in the new encoding.
- Configure the editor font and size.
- The current version saves via the toolbar Save button. Ctrl + S and Save as are not bound yet.
Text preview is limited to 100 MB. Larger files are treated as binary and can be opened in the hex view.
Saving and backups#
The save sequence is:
- Write changes to a temporary file in the same folder.
- Copy the original file to
Documents/FNSoftware/SigXor/Backups/. - Atomically replace the original with the temporary file.
A crash or power loss during saving therefore cannot leave the original half-written. Backups accumulate over time; prune the folder occasionally.
Hex editor#
A custom WPF control virtualizes scrolling through IScrollInfo, so memory use is independent of file size. It uses the classic three-column layout:
Offset | Hex bytes | ASCII
Features:
- Byte editing: overwrite, insert and delete.
- Offset jumps: type an offset to jump directly.
- Hex search: search by hex string or ASCII text.
- Multiple copy formats: hex string, ASCII text and C array.
- Change highlighting: edited bytes are highlighted.
Shortcuts#
| Key | Action |
|---|---|
| 0-9, A-F | Enter a hex byte |
| Tab | Switch between hex and ASCII |
| Insert | Toggle overwrite / insert mode |
| Delete / Backspace | Delete bytes |
| Ctrl + A | Select all |
| Ctrl + C | Copy hex string |
| Ctrl + Shift + C | Copy ASCII text |
| Ctrl + Alt + C | Copy as C array |
| Ctrl + Home / End | Jump to start / end |
Limits#
- Files up to 1 GB stay smoothly editable. Larger files can still be viewed, but write performance depends on disk and memory.
- Editing does not change file permissions or ownership; the target must be writable.
- A file locked exclusively by another program cannot be saved. Close the other program first.
Read-only content#
The following never enter the edit path:
- Office documents (docx / xlsx / pptx / RTF / ODF).
- PDF, web pages and audio.
- Images.