Re: Unexpected Quick Substitution in string literals

[Chet Ramey]

On 12/13/23 12:20 AM, Sundeep Agarwal wrote:

> Bash Version: 5.0
> Patch Level: 17
> Release Status: release
>
> Description:
>
> While declaring a string literal across multiple lines, a line starting
> with the ^ character is resulting in some sort of quick substitution
> processing.

This is a standard form of history expansion, described in the man page.

> I do not have the latest Bash on my machine, but somebody else got the same
> result on the 5.2.21 version. 

For a long time, history expansion was stateless: it worked on a line at
a time, and didn't know anything about the calling application's quoting
state. Bash simply didn't call history expansion if it was parsing a
single-quoted string.

That generated complaints, since people wanted history expansion after
the closing quote on a line that started out single-quoted, so I moved
this functionality into the history library itself, and there became a
way to tell the history library the current quoting state of a line.

The quick substitution feature didn't pay attention to the quoting state,
however, and just translated the line into a standard history expansion,
which was then skipped. The fix is to have it inhibit quick substitution
the same way as other history expansions.

--
``The lyf so short, the craft so long to lerne.'' - Chaucer
                 ``Ars longa, vita brevis'' - Hippocrates
Chet Ramey, UTech, CWRU    chet@case.edu    http://tiswww.cwru.edu/~chet/

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