WETTER_CACHE_DIR: use XDG_CACHE_HOME as fallback

Co-authored-by: kmein <kmein@posteo.de>

1 files changed, 12 insertions, 9 deletions

diff --git a/wetter b/wetter
index 0fb3407..dc5a109 100755
--- a/wetter
+++ b/wetter
@@ -8,9 +8,9 @@
 #       wetter [LONGITUDE,LATITUDE]
 #
 # ENVIRONMENT
-#       WETTER_CACHE_DIR
-#             If set, the specified location will be used to cache HTTP
-#             responses.
+#       WETTER_CACHE_DIR (default: $XDG_CACHE_HOME/wetter or nothing)
+#             If set to a non-empty string, the specified directory will be
+#             used to cache HTTP responses.
 #
 #       WETTER_API_ROOT_URL
 #       WETTER_TOKEN_URL
@@ -34,15 +34,18 @@ main() {
   token_url=${WETTER_TOKEN_URL-https://api.weatherpro.com/v1/token/weather}
   api_root_url=${WETTER_API_ROOT_URL-https://point-forecast-weatherpro.meteogroup.com}
 
-  cache_dir=${WETTER_CACHE_DIR-}
-  if test -z "$cache_dir"; then
-    debug "no cache directory set: caching disabled"
+  if test -n "${WETTER_CACHE_DIR+x}" && test -z "$WETTER_CACHE_DIR"; then
+    debug "WETTER_CACHE_DIR set to the empty string: caching disabled"
+    cache_dir=
     token_cache=
-  elif ! test -d "$cache_dir"; then
-    debug "cache directory $cache_dir does not exist: caching disabled"
+  elif test -z "${XDG_CACHE_HOME-}"; then
+    debug "neither WETTER_CACHE_DIR nor XDG_CACHE_HOME set: caching disabled"
+    cache_dir=
     token_cache=
   else
-    token_cache=$WETTER_CACHE_DIR/api.weatherpro.com%1Fv1%1Ftoken%1Fweather
+    cache_dir=${WETTER_CACHE_DIR-${XDG_CACHE_HOME-$HOME/.cache}/wetter}
+    token_cache=$cache_dir/api.weatherpro.com%1Fv1%1Ftoken%1Fweather
+    mkdir -p "$cache_dir"
   fi
 
   token=$(get_token "$token_url" "$token_cache")