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From: Geoff Clare <geoff@clare.See-My-Signature.invalid>
Newsgroups: comp.unix.shell
Subject: Re: Default PATH setting - reduce to something more sensible?
Date: Thu, 23 Jan 2025 13:04:44 +0000
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Kaz Kylheku wrote:

> On 2025-01-22, Geoff Clare <geoff@clare.See-My-Signature.invalid> wrote:
>> Axel Reichert wrote:
>>
>>> tilde expansion is not, AFAIK, included in POSIX
>>
>> Incorrect.  See XCU 2.6.1 Tilde Expansion, which includes the following:
>>
>>     In an assignment (see XBD Section 4.26), multiple tilde-prefixes
>>     can be used: one at the beginning of the word (that is, following
>>     the <equals-sign> of the assignment), or one following any unquoted
>>     <colon>, or both.
>>
>> The reason this is there is for things like PATH=~/bin:~/sbin:/bin:...
> 
> But surely that must be expanded before PATH is assigned.

Yes, of course.

> PATH is processed by the "p" exec functions like execlp. I don't
> think these perform tilde expansion!

Correct.

> So the reason for using tilde in PATH assignments is the same reason
> as using them in any other shell programming situation; to save
> keystrokes over typing $HOME.

Yes.  Perhaps I trimmed too much.  The post I was replying to said
"$HOME/bin [..] is better than ~/bin, because tilde expansion is not,
AFAIK, included in POSIX" and $HOME is also, of course, expanded before
PATH is assigned.  So there is no reason to prefer $HOME/bin over ~/bin
since (when used in an assignment) they are equivalent in POSIX.

-- 
Geoff Clare <netnews@gclare.org.uk>