Is it possible, or is there some elegant hack to do indirect variable expansion in POSIX as can be done in Bash?
For context, I'm trying to do the following:
for key in ${!map_*}
do
# do something
done
EDIT: To clarify, I'd like to access shell variables that begin with map_.
The hack is to use eval:
aaa=1
aab=2
aac=3
eval_like() {
pattern=$1
vars=`set |grep "^$pattern.*=" | cut -f 1 -d '='`
for v in $vars; do
eval vval="\$$v"
echo $vval
done
}
for i in `eval_like aa`; do
echo $i
done
set was what I was looking for.
QUERYSTRING=$'\nmap_$(reboot)=x'). Also beware that the bash shell includes the list of functions in the output of set (when not running as sh).
map_*).shVSbash-- see stackoverflow.com/a/5725402/1172302.