Prefix and postfix elements of a bash array
arrays, bash, regex
Solution
Bash 5.2 uses substring matching by default (see patsub_replacement):
$ a=(1 2 3)
$ echo "${a[@]/*/'prefix'&'suffix'}"
prefix1suffix prefix2suffix prefix3suffix
Problem
I want to pre- and postfix an array in bash similar to brace expansion. Say I have a bash array ``` ARRAY=( one two three ) ``` I want to be able to pre- and postfix it like the following brace expansion ``` echo prefix_{one,two,three}_suffix ``` The best I've been able to find uses bash regex to either add a prefix or a suffix ``` echo ${ARRAY[@]/#/prefix_} echo ${ARRAY[@]/%/_suffix} ``` but I can't find anything on how to do both at once. Potentially I could use regex captures and do something like ``` echo ${ARRAY[@]/.*/prefix_$1_suffix} ``` but it doesn't seem like captures are supported in bash variable regex substitution. I could also store a temporary array variable like ``` PRE=(${ARRAY[@]/#/prefix_}) echo ${PRE[@]/%/_suffix} ``` This is probably the best I can think of, but it still seems sub par. A final alternative is to use a for loop akin to ``` EXPANDED="" for E in ${ARRAY[@]}; do EXPANDED="prefix_${E}_suffix $EXPANDED" done echo $EXPANDED ``` but that is super ugly. I also don't know how I would get it to work if I wanted spaces anywhere the prefix suffix or array elements.