[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Re: common idiom for user definable substitution variables and defaults
From: |
Ralf Wildenhues |
Subject: |
Re: common idiom for user definable substitution variables and defaults |
Date: |
Sun, 18 May 2008 12:06:30 +0200 |
User-agent: |
Mutt/1.5.17+20080114 (2008-01-14) |
Hello,
* John Calcote wrote on Fri, May 16, 2008 at 11:07:45PM CEST:
> Peter Michaux wrote:
> > AC_SUBST(XJS_LOAD_PATH)
> > if [[ -z "${XJS_LOAD_PATH}" ]]
> > then
> > XJS_LOAD_PATH=".:~/lib/xjs:/usr/local/lib/xjs:/usr/lib/xjs:/lib/xjs"
> > fi
> > For one thing, the double brackets are just single brackets in my
> > configure file. That is ok but how to quote brackets? Do I just want
> > four brackets on each side?
>
> You could just use "test":
True. This chapter has all the gory (ugly) details about M4 quoting:
<http://www.gnu.org/software/autoconf/manual/html_node/M4-Quotation.html>
> test -z "${XJS_LOADPATH}" && XJS_LOAD_PATH="..."
> AC_SUBST(XJS_LOAD_PATH)
Also, if the user may have wanted to set XJS_LOAD_PATH to empty, you can
use
: ${XJS_LOAD_PATH=".:..."}
You may want to consider using $HOME instead of ~ as not all shells do
tilde expansion.
Cheers,
Ralf