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From: Keith Thompson <Keith.S.Thompson+u@gmail.com>
Newsgroups: comp.unix.shell
Subject: Re: Default PATH setting - reduce to something more sensible?
Date: Thu, 23 Jan 2025 14:46:42 -0800
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Kaz Kylheku <643-408-1753@kylheku.com> writes:
[...]
> The obvious situation is double quotes. Inside double quotes, parameter
> expansion happens, but not tilde expansion (not to mention pathname
> expansion (globbing) and perhaps some other things).
>
> So this won't work:
>
>  PATH="$PATH:~/bin"
>
>> Sorry I don't have details, but it is true nonetheless.
>
> There they are.
[...]

In fact it probably will *partially* work.  As I mentioned elsethread,
bash expands a leading ~ (or even ~username) in an element of $PATH when
executing a command.

But if you run a program from the command line that invokes another
program (say, a C program that calls system()), it won't treat that
element of $PATH the same way.

For this and other reasons, though you *can* have a literal ~ in $PATH
in bash, it's best to avoid it and use $HOME instead.  A literal '$HOME'
won't work at all, but that's less likely to be a problem if your at all
aware of how double quotes work in the shell.

I suggest that bash's undocumented behavior is less than helpful.
I'll probably submit a bug report.

-- 
Keith Thompson (The_Other_Keith) Keith.S.Thompson+u@gmail.com
void Void(void) { Void(); } /* The recursive call of the void */