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Trygnuapl strips all boxing & line-drawing characters from the line submitted to GNU APL.

The following keyboard shortcuts are acted on by trygnuapl and will only work if the key combination is not in use by the desktop environment, window manager, or the web browser.

Inside the REPL:

Ctrl+P	Previous command in the history list1
Ctrl+N	Next command in the history list1
Ctrl+U	Erase to the beginning of the line, i.e. the 4BSD stty(1) "kill" character
Ctrl+W	Erase the word to the left, i.e. the 4BSD stty(1) "werase" character
Ctrl+H	Backspace, traditionally, i.e. the stty(1) "erase" character
Ctrl+E	readline(3) move to the end of the line
Ctrl+A	readline(3) move to the start of the line
Escape	alternative move to the start of the line

Inside the multi-line editing buffer:

Ctrl+A,E,U,W,H and Escape	As above
Shift+Enter	Submit entire buffer to GNU APL
Ctrl+Enter	Submit entire buffer to GNU APL

Speed tip: to rapidly set focus and enter a new APL command, click in the REPL and then press Ctrl+N. The cursor (caret) is transported to the end and ready for input. Use xclip(1) to paste local files' contents into the MLEB.

1. GNU APL has a complete command history feature, including context sensitive history recall and history line display filtering. Due to the stateless nature of the trygnuapl server architecture, this GNU APL feature can not be showcased. Instead, trygnuapl's browser interface implements command history substitution differently from GNU APL.

Trygnuapl history substitution in the REPL:

)hi	To show the history list
)hi clear	To clear the history list; beware, )clear is very different
!n	Reissue command n>0 from the history list
!-n	An offset, referring to the command n before the current command
!!	Previous command in the history list
!s	The most recent command whose first word begins with the string s
!?s	The most recent command which contains the string s
^string1^string2	Repeat the previous command, replacing string1 with string2
^^string	Prepend string to the the previous command

The ! character that introduces the history substitution feature of trygnuapl must be exactly on column 7 in the REPL after the six space APL prompt. If not, the line is passed to GNU APL for interpretation. Also, characters following the ! must not have intervening space, else the line is passed to GNU APL. To evaluate n factorial in the REPL, consider ! n or (!n) or ⊢!n.

GNU APL comes with two documents: A Quick Tour of GNU APL and a slightly more detailed info manual.