* On 07 Jan 2011, Yue Wu wrote:
> On Fri, Jan 07, 2011 at 03:40:12PM +0800, du yang wrote:
> >
> > if [ $(date -d "$(date '+%Y-%m-%d')" "+%s") -gt $epoch ]; then
> > echo "%4C %Z %{%d.%m.%y} %-15.15F (%?l?%4l&%4c?) %?H?[%H]?%s%"
> > else
> > echo "%4C %Z %{ %H:%M} %-15.15F (%?l?%4l&%4c?) %?H?[%H]?%s%"
> > fi
>
> Must it be bash script? No bash here, it fails the test with sh...
This is a POSIX sh script, not Bourne, which is why it fails for you.
Specifically, $(command) is a POSIX construction that is not supported
by conventional Bourne shells. You can fix it by replacing this:
if [ $(date -d "$(date '+%Y-%m-%d')" "+%s") -gt $epoch ]; then
with this:
now=`date '+%Y-%m-%d'`
if [ `date -d "$now" "+%s"` -gt $epoch ]; then
However, if I'm not mistaken that command still relies on GNU extensions
to the "date" command. (Mixing POSIX and GNU is another common
portability problem in the Linux era.) Since you appear to be using
FreeBSD you may have problems with that even after adapting the shell
syntax. (In fact I think it's even more confusing. Where the -d
option will simply fail on a pure POSIX system, I think it is actually
a completely different option on BSD, which has its own extensions
separate from GNU's.)
Remember that setting $index_format to a piped command means that the
command is run once each time a message is displayed on your index. I
wrote the code to allow $index_format to be a piped command, and as I
remember the result is *not* cached. Since the command in this case is
a shell script, it's actually going to run three commands: sh, date, and
another date.
For these reasons -- portability and performance -- I would not use
shell for this purpose. I prefer Python, but Perl might be a better
choice since it typically has a lower startup time. Naturally for
performance concerns, C would be the best choice.
--
David Champion * [email protected] * IT Services * University of Chicago
