Justin Clift writes: > i.e. if [ -x "$self_path/postmaster" ] && [ -x "$self_path/psql" ]; > then > > or > > if [[ -x "$self_path/postmaster" && -x "$self_path/psql" ]]; then
I don't think the second one is a valid expression. ;-) Maybe you were wondering about [[ ]] vs [] -- In Autoconf [] are the quote characters so you have to double-quote, sort of. It's better to use 'test' in that case because m4 quoting can be tricky. I prefer test over [] in general because it is more consistent and slightly clearer. > if [ x"$foo" = x"" ]; then Maximum safety for the case where $foo starts with a dash. Yes, that means all comparisons should really be done that way. No, I don't think we should do it in all cases if we know what $foo can contain, because that makes code *really* unreadable. > or > > if [ "$op" = "" ]; then > > or > > if [ "$foo" ]; then These two are equivalent but the second one is arguably less clear. -- Peter Eisentraut [EMAIL PROTECTED] http://funkturm.homeip.net/~peter ---------------------------(end of broadcast)--------------------------- TIP 4: Don't 'kill -9' the postmaster
