Bash/Linux: terminal rows and columns are not read properly by default

[kmsquire]

In Bash, Julia always starts now assuming that I have 25 rows and 80 columns. This wasn't always the case, although I'm not sure yet when the change happened.

tty_rows() and tty_cols() determine rows and columns by reading the LINES and COLUMNS environment variables. However, these variables are shell variables in bash, and are not set as environment variables by default. (See: http:https://mywiki.wooledge.org/BashFAQ/091)

Related: #4513

[kmsquire]

Well, maybe I'm wrong and this never worked, and the systems I was on set LINES and COLUMNS as environment variables. I see the same behavior on Julia 0.2.1.

[kmsquire]

I take that back. Running ./julia -e 'println(Base.tty_rows(), " ", Base.tty_cols())' from the command line always shows 25 80, but interactively, the proper values used to be set (and are no longer).

[staticfloat]

I too see this on OSX, even with things like shopt -s checkwinsize enabled.

[kmsquire]

I'm git bisecting right now.

[simonster]

I think readline used to read the terminal size on startup, even though we broke updating the size on terminal resize at some point. It looks like Terminals actually has a function that calls libuv to get the TTY size (check size(Base.active_repl.t)) but we don't currently call it on startup. I'll play around with it.

[kmsquire]

Thanks, Simon. FWIW, it was the introduction of the new REPL where this was lost, which makes perfect sense.