LibLine: Missing GNU Shortcuts

[RolandMarchand]

Some GNU Bash/Readline shortcuts are not implemented in LibLine as of the latest commit c136280891.

Missing shortcuts (in order of personal usage):

• Alt+b: Back (left) one word
• Alt+f: Forward (right) one word
• Alt+d: Delete the Word after the cursor
• Alt+t: Swap current word with previous
• Alt+u: UPPER capitalize every character from the cursor to the end of the current word
• Alt+l: Lower the case of every character from the cursor to the end of the current word
• Alt+c: Capitalize the character under the cursor and move to the end of the word
• Сtrl+_: Undo
• Ctrl+xx: Toggle between the start of line and current cursor position
• Alt+r: Cancel the changes and put back the line as it was in the history (N/A, Shell's history is copied, not reference)

Note: I may have missed some, especially related to history, but these are the most commonly used and best documented ones.

Shell already implements many existing GNU Bash shortcuts, so I am proposing to extend the list.

I am not sure if the existing shortcuts are specifically implemented in LibLine, or in Shell, Terminal, or elsewhere. Since GNU Readline implements those shortcuts, I think LibLine should, too, if it was to have them.

Edit: this issue might be a good fit for the label "good first issue."

[nico]

Pretty sure we have at least most of these? #3027 added u, l, c for example.

[RolandMarchand]

Huh, that's curious. I confirm to have tested all the shortcuts listed above, and they are not implemented as of c136280891cecfdd935f470abfa1fef3a3eeee2d. I can provide more detail about my build if requested.

[alimpfard]

Here's a list of all the implemented keybinds:

• ctrl('N')
• ctrl('P')
• ctrl('A')
• ctrl('B')
• ctrl('D')
• ctrl('E')
• ctrl('F')
• ctrl('H')
• DEL
• ctrl('K')
• ctrl('L')
• ctrl('R')
• ctrl(']')
• Key { ctrl(']'), Key::Alt }
• ctrl('T')
• '\n'
• Vector<Key> { ctrl('X'), ctrl('E') }
• Key { '.', Key::Alt }
• ctrl('Y')
• Key { 'b', Key::Alt }
• Key { 'f', Key::Alt }
• Key { ctrl('B'), Key::Alt }
• Key { ctrl('F'), Key::Alt }
• Key { '\b', Key::Alt }
• Key { 'd', Key::Alt }
• Key { '\\', Key::Alt }
• Key { 'c', Key::Alt }
• Key { 'l', Key::Alt }
• Key { 'u', Key::Alt }
• Key { 't', Key::Alt }
• m_termios.c_cc[VWERASE]
• m_termios.c_cc[VKILL]
• m_termios.c_cc[VERASE]

Of the list mentioned by the OP, these are not implemented:

• ctrl('_')
• Vector<Key> { ctrl('X'), ctrl('X') }
• Key { 'r', Key::Alt }

As for Alt+{u,l,c} not working, I just tested them (on lagom) and they're fine; might be a Terminal issue if you're testing from within Serenity.