Re: Bash 5.1: Make shell_script_filename available to startup files

[Zachary Santer]

On Sat, Feb 17, 2024 at 3:44 PM Marc Aurèle La France <tsi@tuyoix.net>
wrote:

> Do ...
>
> rm -fr GREPME grepme
> echo '#! /bin/bash\nset' > GREPME
> "ln" GREPME grepme
> chmod a+x grepme
>
> ... then (case matters) ...
>
> BASH_ENV=GREPME ./grepme | fgrep -iw grepme
>
> ... gives ...
>
> BASH_ARGV=([0]="GREPME")
> BASH_ENV=GREPME
> BASH_SOURCE=([0]="GREPME")
> _=./grepme
> BASH_ENV=GREPME
> BASH_SOURCE=([0]="./grepme")
>
> ... so $_ wins, not $BASH_SOURCE[0]
>

Sorry I didn't read your original email chain from 2021 before responding
earlier.

You want a script sourced because it's given as ${BASH_ENV} to be able to
tell what script it was sourced from?

If you're satisfied with $_ or now $0, then fine, but I would actually
expect that to show up as ${BASH_SOURCE[1]} within the ${BASH_ENV} script,
which it obviously doesn't. Don't know what ${BASH_LINENO[0]} ought to be
in that case. Maybe 0?

The way the manual explains BASH_SOURCE and BASH_LINENO is all in
reference to FUNCNAME, which doesn't exist (or is empty) if you're not
executing a function. Still, with explicit sourcing, this is the behavior
we see:

zsant@Zack2021HPPavilion MINGW64 ~/random
$ cat original-file
#!/bin/bash
source ./sourced-file

zsant@Zack2021HPPavilion MINGW64 ~/random
$ cat sourced-file
declare -p BASH_SOURCE BASH_LINENO

zsant@Zack2021HPPavilion MINGW64 ~/random
$ ./original-file
declare -a BASH_SOURCE=([0]="./sourced-file" [1]="./original-file")
declare -a BASH_LINENO=([0]="2" [1]="0")

So this would seemingly be more consistent and not require a whole new
shell variable.