Terminal Text Editor (C++ / ncurses)

A minimal terminal text viewer/editor written in C++ with ncurses. It opens a file, renders it line-by-line, and lets you move a cursor and run simple : commands (:q, :i). This is a learning project focused on terminal UI, file I/O, and keystroke handling.

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Features

• Open and display a text file line-by-line.
• Arrow-key cursor movement on the rendered text.
• : commands:
  • :q — quit viewer
  • :i — enter insert/navigation routine (work-in-progress)
• Handles Windows CRLF files by stripping \r so lines don’t overwrite.

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How It Works (Quick Overview)

• ncurses rendering: You update a virtual screen; refresh() pushes it to the terminal. Cursor moves with move(y, x) (origin top-left (0,0), y = row, x = column).
• Input: getch() returns key codes. Use cbreak() to get keys immediately and keypad(stdscr, TRUE) so arrow keys arrive as KEY_UP/DOWN/LEFT/RIGHT.
• Streams: After reading to EOF, call clear() then seekg(0) (or reopen) before reading again.
• CRLF: If the file came from Windows, each line may end with \r\n. getline strips \n but leaves \r. The code trims trailing \r to prevent cursor resets.

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Build

Install build tools and ncurses headers (Debian/Ubuntu/Kali/WSL):

sudo apt update
sudo apt install build-essential libncurses-dev

Compile:

g++ main.cpp -o textedit -lncurses

Note: The -lncurses link flag is required at link time.

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Run

./textedit

Opening Windows files from WSL

Use the /mnt/<drive>/... mapping, e.g. C:\Users\you\file.txt → /mnt/c/Users/you/file.txt.

“Only last line shows”?

That’s typically CRLF input. Convert once with:

dos2unix /path/to/file.txt

(Or rely on the built-in \r stripping.)

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Usage

1. Start the program → Menu:

   • 1. Open file — enter a path (on WSL, use /mnt/...).
   • 2. Create file — placeholder for future work.
   • 3. Quit

2. In the viewer:

   • Arrow keys — move the cursor (rows increase downward).
   • : then q — quit.
   • : then i — enter insert/navigation routine (WIP).

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Project Structure (Current)

.
├─ main.cpp        # menu (Setup::setup/state/edit) + Commands::i()
└─ README.md

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Internals You’ll Want to Remember

• move(y, x) is (row, col); you must call refresh() to see it.
• cbreak() + keypad(stdscr, TRUE) are needed so getch() returns arrow keys as KEY_*.
• When reusing a std::fstream after EOF: file.clear(); file.seekg(0);.
• Keep cursor bounds within the window size (LINES, COLS) and within the current line length for horizontal moves.

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Roadmap

• Real insert mode (edit lines in memory; write back to disk).
• Scrolling viewport (firstVisibleLine, re-render region).
• Status bar (filename, row:col, mode).
• Search (/pattern), jump to line.

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Troubleshooting

• Undefined references to initscr/printw — link with -lncurses.
• Arrow keys print weird characters — ensure cbreak() and keypad(stdscr, TRUE) are set.
• Can’t open C:\... from WSL — use /mnt/c/... mapping.
• Screen doesn’t update — call refresh() after drawing or moving the cursor.

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License

MIT (or your choice).