dctlenv/libexec/dctlenv-list

#!/usr/bin/env bash
set -uo pipefail

[ -d "$DCTLENV_ROOT/versions" ] || log_error 'No versions of driftctl installed. Please install one with: dctlenv install [<version>]'

[[ -x "$DCTLENV_ROOT/versions" && -r "$DCTLENV_ROOT/versions" ]] \
  || log_error "dctlenv versions directory is inaccessible: $DCTLENV_ROOT/versions"

version_file="$(dctlenv-version-file)" \
  && log_debug "dctlenv-version-file reported: $version_file"

version_name="$(dctlenv-version-name 2>/dev/null)" \
  && log_debug "dctlenv-version-name reported: $version_name"

log_debug 'Listing versions...'
local_versions=($(\find "$DCTLENV_ROOT/versions" -type d -exec basename {} \; \
  | tail -n +2 \
  | sort -t'.' -k 1nr,1 -k 2nr,2 -k 3nr,3))

log_debug "Local versions: ${local_versions[@]}"

log_debug 'Printing versions...'
for local_version in ${local_versions[@]}; do
  if [ "$local_version" == "$version_name" ]; then
    echo "* $local_version (set by $version_file)"
  else
    echo "  $local_version"
  fi
done