Re: Redirection and Variables

[Peter Stephenson <pws@xxxxxxx>]

Nikolai Weibull wrote:
> A couple of questions:
> 
> Is this the simplest way to do the following?
> 
> local -A http_programs https_programs mailto_programs ftp_programs
> 
> http_programs=(xw "/usr/bin/firefox -remote 'openURL(%s, new-tab)'"
>                xt "/usr/bin/elinks '%s'")
> http_programs=(xw "/usr/bin/firefox -remote 'openURL(%s, new-tab)'"
>                xt "/usr/bin/elinks '%s'")
> mailto_programs=(xt "/usr/bin/mutt '%s'")
> ftp_programs=(xt "/usr/bin/lftp")
> 
> lookup () {
>   echo "${(P)$(echo ${1}_programs\[xw\])}"
> }

Using eval would be nicer than the $(...), but actually there's a hack
to avoid even that:

lookup() {
  echo ${(P)${:-$1_programs[xw]}}
}

The empty nested substitution always returns the string after the :-,
which undergoes expansion, so the (P) flag can operate on that.

> If I have the following in a script that reads input from stdin:
> 
> sed -n "s/$REGEX/\1\n/gp" <&0 | sed "/$REGEX/!d" > $TMP
> if [[ ! -s $TMP ]]; then
>   rm -f $TMP
>   exit 1
> fi
> ${EDITOR:-vi} $TMP
> 
> my $EDITOR (vim) will complain that 
> "Vim: Warning: Input is not from a terminal".  Is there a simple way to
> get around this?

Are you saying the early part is important, i.e. if you just run vi in
the script without the earlier bit it works?  That sounds unlikely,
although I haven't investigated in detail.  If that's not the case, you
probably need to do some direction to force vi to use /dev/tty.

I'm not sure why you have "<&0", that simply redirects standard input
from standard input.

-- 
Peter Stephenson <pws@xxxxxxx>                  Software Engineer
CSR Ltd., Science Park, Milton Road,
Cambridge, CB4 0WH, UK                          Tel: +44 (0)1223 692070



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