Tweak FAQ answer for passing julia options in a script file.

[fredrikekre]

In particular, this now sets PROGRAM_FILE (and thus can be combined with https://docs.julialang.org/en/v1/manual/faq/#How-do-I-check-if-the-current-file-is-being-run-as-the-main-script?-1):

$ cat script1.jl
#!/bin/bash
#=
exec julia --color=yes --startup-file=no -e 'include(popfirst!(ARGS))' \
    "${BASH_SOURCE[0]}" "$@"
=#

@show PROGRAM_FILE

$ ./script1.jl 
PROGRAM_FILE = ""

$ cat script2.jl
#!/bin/bash
#=
exec julia --color=yes --startup-file=no "${BASH_SOURCE[0]}" "$@"
=#

@show PROGRAM_FILE

$ ./script2.jl 
PROGRAM_FILE = "./script2.jl"

cc @tkf, since you authored #29423, is there something I am missing here or is this strictly better?

[tkf]

is there something I am missing here or is this strictly better?

I think this is a trade-off (so I don't think it's strictly better, unfortunately). As mentioned in How do I catch CTRL-C in a script?, include(popfirst!(ARGS)) is actually useful if you want to catch InterruptException in a script. (Aside: It would be nice to have a command line flag (say) to make InterruptException capturable in a script without "sacrificing" PROGRAM_FILE; ref #29383).

But, for the purpose of FAQ, I agree mentioning the simplest usecase (as in this PR) is probably better.

[fredrikekre]

I see, I can add the original version in a note then maybe.

[fredrikekre]

@tkf I updated with the note, do you wanna take another look?

[KristofferC]

If this is what determines if Ctrl-C can be caught:

julia/base/client.jl

Lines 284 to 286 in 6f69067

	if !is_interactive
	ccall(:jl_exit_on_sigint, Cvoid, (Cint,), 1)
	end

an alternative would be to document that function instead of having the indirect workaround with using `-e 'include("...")'.

[tkf]

@fredrikekre Thanks for adding a note for include(popfirst!(ARGS)). The PR looks perfect to me! 👍

an alternative would be to document that function

@KristofferC I guess you are suggesting to wrap jl_exit_on_sigint as a Julia function and document it? Yes, that sounds like a cleaner solution.