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From: gazelle@shell.xmission.com (Kenny McCormack)
Newsgroups: comp.unix.programmer
Subject: Word splitting oddities (Was: Long filenames in DOS/Windows and Unix/Linux)
Date: Sat, 7 Sep 2024 21:51:29 -0000 (UTC)
Organization: The official candy of the new Millennium
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References: <9e7a4bd1-bfbb-4df7-af1a-27ca9625e50bn@googlegroups.com> <ygay146mot1.fsf@akutech.de> <wwvy1463tkk.fsf@LkoBDZeT.terraraq.uk> <slrnvdp692.1s5hi.candycanearter07@candydeb.host.invalid>
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In article <slrnvdp692.1s5hi.candycanearter07@candydeb.host.invalid>,
candycanearter07  <candycanearter07@candycanearter07.nomail.afraid> wrote:
....
>>> Only sometimes it doesn't :-)
>>>
>>>     $ foo="foo bar"
>>>     $ bar=$foo
>>>
>>> No problem with the space in the expanded value here!
>>>
>>>     $ echo $bar
>>>     foo bar
>>>
>>> but of course:
>>>    ls $bar
>>>    ls: cannot access 'foo': No such file or directory
>>>    ls: cannot access 'bar': No such file or directory
>>
>> Fair point. Field splitting happens after parameter expansion, except
>> when it doesnt.
>
>
>Actually, echo is special since it just prints every argument it's
>given.. both of these commands are working as expected with splitting:
>
>	$ echo some text
>
>	some text
>
>	$ ls some text
>
>	ls: cannot access 'some': No such file or directory
>	ls: cannot access 'text': No such file or directory

The point is still valid, even if the demonstration wasn't quite on-point.

When faced with the problem of needing to display a variable in shell, but
needing to know whether or not it is a single string or multiple strings, a
useful trick is to use "printf" like this:

    $ set -- this is "a test of" something
    $ printf "%s\n" "$@"

Then you would know for sure that in the example above, the variable "foo"
really did have the value "foo bar".

Note, incidentally, that in the example above, the statement: bar=$foo
pretty much has to be parsed as if $foo had been quoted, because the
alternative is much worse.  The alternative would be to interpret:

    bar=$foo
as
    bar=foo bar

which means to run the "bar" command with the env var "bar" set to "foo".

-- 
Trump has normalized hate.

The media has normalized Trump.