On 9/19/07, matthew sporleder <msporleder@gmail.com> wrote:
> On 9/19/07, Martin Bock <ixel@gmx.de> wrote:
> > Hello!
> >
> > I am having trouble to understand ksh behaviour in context of patterns,
> > parameters and the case-statements:
> >
> > The following is what I expected:
> > ------------------------------------------------
> > $ cat script1.sh
> > #!/bin/ksh
> > for file in foo bar baz; do
> >         case $file in
> >                 foo)    echo foo;;
> >                 baz|bar) echo ba;;
> >                 *)      echo default;;
> >         esac
> > done
> > $ ksh script.sh
> > foo
> > ba
> > ba
> > ------------------------------------------------
> >
> > But with a minor modification it does not work as expected:
> > ------------------------------------------------
> > $ cat script2.sh
> > #!/bin/ksh
> > foopattern="foo"
> > bapattern="baz|bar"
> > for file in foo bar baz; do
> >         case $file in
> >                 $foopattern)    echo foo;;
> >                 $bapattern)     echo ba;;
> >                 *)              echo default;;
> >         esac
> > done
> > $ ksh script2.sh
> > foo
> > default
> > default
> > ------------------------------------------------
> > Note the parameters containing the patterns for the case statement.
> > Apparently the | symbol does not do the desired magic within paramters.
> >
> > Now, where is the meaning of the | as in script1.sh explained in ksh(1)?
> > While very common usage, I could not seem to find it after several reads
> > of that manpage.
> >
> > Why does the version in script2.sh not work? In particular the patterns
> > before ) in the case statement are -- according to ksh(1) -- subject to
> > parameter expansion.
> >
> > VWIW, this is NetBSD 3.1
>
> ksh is interpreting the | literally.  This works:
> foopattern="foo"
> barpattern="bar"
> bazpattern="baz"
> for file in foo bar baz;
> do
>  case $file in
>   "${foopattern}") echo foo
>    ;;
>   "${barpattern}"|"${bazpattern}") echo bar
>    ;;
>   *) echo default
>    ;;
>  esac
> done
>
> However, that does not follow the man page:
> "Both the word and the patterns are subject to parameter, command, and
>  arithmetic substitution as well as tilde substitution."
>
> No amount of quoting or *(pattern) tricks would work for me, so I
> think you may have a bug here.
>

bash seems to behave the same way as our pdksh in this case.