editing text in a REPL doesn’t always work

little stick figure, horrified: when I press my ARROW KEYS it just prints out [[D??? what?

this is because every program has fo implement text editing itself

terminal program author, represented by a nonplussed looking stick figure with medium length straight hair, thinking: but I just want arrow keys to work?? shouldn’t that be automatic?

unix, represented by a box with a smiley face: NOPE you gotta do it

you do gef a few things automatically

• backspace (occasionally backspace won’t work and you have to use Ctrl+H instead)
• Ctrl+W (delete word)
• Ctrl+U (delete line)

(see page 25 for what “automatically” means)

REPLs mostly have the same keyboard shortcuts

there’s a very popular library called “readline”, and everyone either uses it or imitates how it works

for example Ctrl+A (“go to beginning of line”) comes from readline

rlwrap adds readline keyboard shortcuts

for example on my machine the dash shell doesn’t use readline but you can make it better by running:

rlwrap dash

built in programs on Mac don’t use readline

(for example sq1ite3)

this is probably because readline is GPL licensed

They use libedit which is worse. I like to install a sqlite version with readline support and use that instead.