[bug #33374] "local" as function name is questionable sh syntax

[Jonathan Nieder]

URL:
  <http://savannah.gnu.org/bugs/?33374>

                 Summary: "local" as function name is questionable sh syntax
                 Project: texinfo - GNU documentation system
            Submitted by: jrn
            Submitted on: Mon 23 May 2011 02:58:33 AM GMT
                Category: texi2dvi
                 Release: 2011-05-21
                Priority: 3 - Low
                Severity: 3 - Normal
              Item Group: enhancement
                 Privacy: Public
             Open/Closed: Open
             Assigned to: None
         Discussion Lock: Any
                  Status: None

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Details:

Hi,

As previously reported at <http://bugs.debian.org/619786>, texi2dvi errors out
when run using recent versions of dash from
git://git.kernel.org/pub/scm/utils/dash/dash.git as shell:

| $ texi2dvi
| /usr/bin/texi2dvi: 144: /usr/bin/texi2dvi: Syntax error: Bad function name
| $ sed -ne 144p /usr/bin/texi2dvi
| ) || local () {
| $ dash -c 'true || local () { echo hi; }; echo continuing'; echo $?
| dash: 1: Syntax error: Bad function name
| 2

The cause is use of "local" as a function name --- like typeset and export,
"local" is a special builtin in these versions of dash, and using it as a
function name is a syntax error[*].

ksh similarly errors out when it sees an attempt to define "export" or
"typeset" as a function, but it does not treat "local" as special, and perhaps
future versions of dash will follow that lead. So I am reporting this not to
say "this construct is invalid shell command language" but rather "this is at
the edge of portability and probably worth avoiding".

Anyway, it's simple to hide this construct from the parser for such shells by
wrapping the function definition in 'eval'.  Shells that support "local" don't
have to parse that code and shells that do not support "local" are not going
to have a problem with it.

Thanks for reading, and hope that helps,
Jonathan

[*] http://austingroupbugs.net/view.php?id=383



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File Attachments:


-------------------------------------------------------
Date: Mon 23 May 2011 02:58:33 AM GMT  Name: texi2dvi-local-fallback-syntax 
Size: 1012B   By: jrn
patch
<http://savannah.gnu.org/bugs/download.php?file_id=23438>

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