Features.md

K21 Features

This document summarizes the changes in k21 (fork of joe2.1), organized by function.

Identity & Branding

• Renamed from Joe to K: The editor is now called "k" instead of "joe"
• Binary output is k (not joe, jmacs, jstar)
• Configuration file is krc (not joerc)
• Crash recovery file renamed from DEADJOE to DEADK
• Error messages reference "K" instead of "JOE"

Session Persistence / Context Saving

• Automatic context saving: On exit, saves current file and line number to ~/.ktx
• Session resume: When launched without arguments, automatically re-opens the last edited file at the saved line position
• Displays "Resuming at line ." message on restore

File Locking

• Advisory file locking:
  • Uses flock() to lock files when opened for editing
  • Prevents concurrent editing of the same file
  • New error message: "Error, file locked" when file is already locked
  • Lock released on buffer close

Enhanced Backup System

• Timestamped backups:
  • Backup filenames include date/time stamp: file~DD-Mon-YY_HH:MM:SS~username
  • Backups organized by user in backpath: creates per-user subdirectory
• Improved error messages show actual backup filename on failure

New Commands

• pgfwd: Page forward (J-compatible mode) — goes to bottom of screen, then pages down
• pgrev: Page reverse (J-compatible mode) — goes to top of screen, then pages up
• playlast: Execute the most recently recorded/executed macro without specifying number

Macro Improvements

• Automatic macro closing: If you try to execute a macro that's still recording, it auto-stops recording first
• Last macro tracking: Remembers which macro was last recorded/played for playlast

Help Navigation

• Circular help navigation: Help screens now cycle — pressing next on last help returns to first, pressing prev on first goes to last
• Help toggle behavior: If help is off, next/prev help turns it on; cycling past end turns it off

Terminal Handling

• Disabled terminal exit sequence (te termcap) on exit — prevents screen clearing

Yank Behavior

• Cursor remains at start of yanked text (original joe moved to end)

Filter Behavior

• Block marks are preserved after filter operations (original joe cleared them)

Exit Messages

• Suppressed "not changed so no update needed" message on exit for unchanged files

File Permissions

• Default umask set to 002 for better group collaboration

Default Configuration (krc)

• -marking enabled by default (live block highlighting)
• -lightoff enabled by default (highlighting clears after block operations)
• -force enabled by default (force final newline)
• -backpath set to /var/tmp/kback/
• -nonotice enabled (disables copyright notice)
• Custom keybindings using ^P, ^L, ^^ as prefix keys
• Custom help screens adapted for K bindings

New Files in k21

• krc — K configuration file
• keys.tpt — Keyboard template/reference showing key bindings