Re: $\n doesn't get expanded between double-quotes

[Richard Neill]

Thanks for your reply.

> > Description:
> >         Bash allows escape characters to be embedded by using the $'\n'  
> > syntax. However, unlike all other $variables,
> >         this doesn't work with embedded newlines. I think it should.
> >
> > Repeat-By:
> >         X="a$'\n'b c"
> >         echo "$X"
> >
> >         expect to see:
> >                 a
> >                 b c
> >
> >         actually see:
> >                 a$'\n'b c
> >
> >
> > Fix:
> > 	$'\n'  should be expanded within double-quotes, like other variables are. 
> > 	Otherwise, please correct the man-page to make it clearer.
>
>    $'\n' is not a variable. As the man page says:
>
>             Words of the form $'string' are treated specially.
>
>    Note "Words". Inside double quotes, $'\n' is not a word.

I agree that this is technically correct. However, it violates the 
principle of least-surprise, which is that, in bash, the $ symbol always 
expands the value of the thing after it, (with the exceptions of
'$' and \$ .)

(On re-reading the man-page, I agree that the documentation is 
consistent with your explanation; though it still appears more likely to 
imply mine)

> >         If this is a feature, not a bug, then is there a better way to include 
> > newlines in a variable-assignment?
> >         The syntax    X="a"$'\n'"b c"    will do it, but that is really really 
> > ugly.
>
> X=$'a\nb c'

This is still a missing feature: how to embed newlines in double-quoted 
bash string assignment:

For example, if I want to write:

EMAIL_BODY="Dear $NAME,$'\n\n'Here are the log-files for 
$(date)$'\n\n'Regards,$'\n\n'$SENDER"

then this doesn't work. There are ways around it, such as:
  - building up the string in pieces or
  - EMAIL_BODY=$(echo -e "$EMAIL_BODY")

but it's really ugly to do.


As I imagine that nobody uses the current $'\n' inside double-quotes, 
may I request this as a functionality change?


Best wishes,

Richard