dctlenv/libexec/dctlenv-use

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

[ "$#" -gt 1 ] && log_error "Need 1 version instead of $#" 'usage: dctlenv use [<version>]'

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

version_requested="${1:-""}"
[ -n "$version_requested" ] || log_error 'Version is not specified' 'usage: dctlenv use [<version>]'

if [[ $version_requested == "latest" ]]; then
  version_requested="$(dctlenv-list-remote | tail -n 1)"
fi

log_debug "Searching $DCTLENV_ROOT/versions for version matching $version_requested"
version="$(\find "$DCTLENV_ROOT/versions" -type d -exec basename {} \; \
  | tail -n +2 \
  | sort -t'.' -k 1nr,1 -k 2nr,2 -k 3nr,3 \
  | grep -e "$version_requested" \
  | head -n 1
)"

if [ -n "$version" ]; then
  log_debug "Found version: $version"
else
  echo "No installed versions of driftctl matched '$version_requested', let's install it"
  $(dctlenv-install $version_requested 1>/dev/null) || log_error "Installation of version $version_requested failed"
  version=$version_requested
fi

target_path="$DCTLENV_ROOT/versions/$version"
[ -f "$target_path/driftctl" ] \
  || log_error "Version directory for $version is present, but the driftctl binary is not! Manual intervention required"
[ -x "$target_path/driftctl" ] \
  || log_error "Version directory for $version is present, but the driftctl binary is not executable! Manual intervention required"

echo "Switching version to v$version"
version_file="$(dctlenv-version-file)"

log_debug "Writing \"$version\" to \"$version_file\""
echo "$version" > "$version_file" || log_error "Failed to switch to v$version"

$(driftctl version 1>/dev/null) || log_error "'driftctl version' failed, something is wrong"

echo "Switching completed"