Thankfully bash tolerates that, if the script author cares, e.g. gnu_sed=gsed if ! command -v $gnu_sed; then gnu_sed=$(detector_wizardry) fi $gnu_s

Thankfully bash tolerates that, if the script author cares, e.g. gnu_sed=gsed if ! command -v $gnu_sed; then gnu_sed=$(detector_wizardry) fi $gnu_sed -Ee ...