Re: Portability of shell parameter expansions (${word%pattern} and friends)?

[Ralf Wildenhues]

Hello Benoit,

* Benoit Sigoure wrote on Tue, Nov 06, 2007 at 03:13:07PM CET:
> On Nov 6, 2007, at 1:01 PM, Akim Demaille wrote:
>> Le 6 nov. 07 à 11:56, Benoit Sigoure wrote :
>>>
>>> What, the parameter expansion ${word%pattern}?  The Autoconf manual 
>>> doesn't say anything about it, so I guessed it was portable.
>>
>> That's the right way to read the manual :)  If you want
>> to know about its support, put a spy in Autoconf.
>
> WDYT people?

There is no need.

>> I would not use it anyway.
>
> Anyone aware of any portability issue with shell parameter expansions?

Solaris 10 /bin/sh knows neither
  ${foo#bar}
  ${foo%bar}
  ${#foo}

It does know
  ${foo:-baz}

but the manual documents:
| `${VAR:-VALUE}'
|      Old BSD shells, including the Ultrix `sh', don't accept the colon
|      for any shell substitution, and complain and die.  Similarly for
|      ${VAR:=VALUE}, ${VAR:?VALUE}, etc.

Last time this issue was raised, the Solaris limitation was still
considered too "common knowledge" for it to end up in the manual.
We may want to reconsider that.

You may want to have a look at the _LT_PROG_XSI_SHELLFNS macro of
Libtool HEAD, at the end of
<http://cvs.savannah.gnu.org/viewvc/libtool/libltdl/m4/libtool.m4?root=libtool&view=markup>

Cheers,
Ralf