more fun with $*

[Thorsten Glaser]

From: Stephane Chazelas <email address hidden>

>BTW, it looks like there's a bug in mksh:

tglase@tglase:~ $ bash -c 'IFS=; x=abc; printf "<%s>\n" ${x#$*}' x a b | sed -n l
<abc>$
tglase@tglase:~ $ ./dash -c 'IFS=; x=abc; printf "<%s>\n" ${x#$*}' x a b | sed -n l
<c>$
tglase@tglase:~ $ ksh93 -c 'IFS=; x=abc; printf "<%s>\n" ${x#$*}' x a b | sed -n l
<c>$
tglase@tglase:~ $ lksh -c 'IFS=; x=abc; printf "<%s>\n" ${x#$*}' x a b | sed -n l
<\a\300a>$
<abc>$
tglase@tglase:~ $ mksh -c 'IFS=; x=abc; printf "<%s>\n" ${x#$*}' x a b | sed -n l
<\a\300a>$
<abc>$
tglase@tglase:~ $ pdksh-5.2.14 -c 'IFS=; x=abc; printf "<%s>\n" ${x#$*}' x a b | sed -n l
<abc>$
tglase@tglase:~ $ mksh -o sh -c 'IFS=; x=abc; printf "<%s>\n" ${x#$*}' x a b | sed -n l
<a>$
<abc>$

>The dash versions I have access to give the expected output
>(same as your ksh93).

>bash and pdksh join the arguments with spaces. And there's
>nothing in POSIX that allows them to do that.

But:

>ksh93 has some other interesting bugs:

tglase@tglase:~ $ bash -c 'IFS="*"; a=abcd; printf "<%s>\n" "$*" ${a##"$*"}' sh '' c
<*c>
<abcd>
tglase@tglase:~ $ ./dash -c 'IFS="*"; a=abcd; printf "<%s>\n" "$*" ${a##"$*"}' sh '' c
<*c>
<abcd>
tglase@tglase:~ $ ksh93 -c 'IFS="*"; a=abcd; printf "<%s>\n" "$*" ${a##"$*"}' sh '' c
<*c>
<d>
tglase@tglase:~ $ lksh -c 'IFS="*"; a=abcd; printf "<%s>\n" "$*" ${a##"$*"}' sh '' c
<*c>
<abcd>
tglase@tglase:~ $ mksh -c 'IFS="*"; a=abcd; printf "<%s>\n" "$*" ${a##"$*"}' sh '' c
<*c>
<abcd>
tglase@tglase:~ $ pdksh-5.2.14 -c 'IFS="*"; a=abcd; printf "<%s>\n" "$*" ${a##"$*"}' sh '' c
<*c>
<abcd>

tl;dr: Fix the first and keep the second as-is.

>And they don't say how those "arrays" are to be cast to scalars
>when not in list context since they don't specify arrays in the
>first place.
>
>The non-list contexts include
>
>a=$*
>${a#$*}
>
>case x in
> $a) ...;;
> "$a") ...
>esac
>${a#"$*"} # beware quotes also serve to cancel globs there
>
>$(( $* ))
>...

Interesting use for the asn subst.

[Thorsten Glaser (mirabilos)]

Preliminary fix committed, plus some test coverage. This is a real problem, raising priority.

Fix needs to be extended; CVS HEAD needs to be tested better.

[Thorsten Glaser (mirabilos)]

mksh R50e is out