Fix bugs on empty input

.config/shell/profile

@@ -16,6 +16,7 @@ export CHROME_EXECUTABLE=chromium # For Flutter
 export XDG_CACHE_HOME="${XDG_CACHE_HOME:-$HOME/.cache}"
 export XDG_CONFIG_HOME="${XDG_CONFIG_HOME:-$HOME/.config}"
 export XDG_DATA_HOME="${XDG_DATA_HOME:-$HOME/.local/share}"
+export XDG_DATA_DIRS="${XDG_DATA_DIRS:-/usr/share}"
 
 # Clean home:
 export ANDROID_HOME="$XDG_DATA_HOME/Android/Sdk"
@@ -64,26 +65,27 @@ rm_env_path_entry() {
     del_entry="${2:?Missing entry to delete}"
     new_entries=""
 
-    echo "$src_entries" | $_tr ':' '\n' | while read -r entry; do
+    for entry in $(echo "$src_entries" | $_tr ':' ' '); do
         if [ "$entry" != "$del_entry" ]; then
             new_entries="$new_entries:$entry"
         fi
     done
 
-    trim "$new_entries" ":"
+    [ -n "$new_entries" ] && trim "$new_entries" ":"
+    echo
 }
 
 modify_env_path() {
     mode="${1:?Missing mode}"
-    entries="${2:?Missing entries}"
+    entries="$2"
     change="${3:?Missing change}"
 
-    entries="$(trim "$entries" ":")"
+    [ -n "$entries" ] && entries="$(trim "$entries" ":")"
 
     case "$mode" in
     prepend)
         temp_entries="" # Will hold the new entries in the correct order
-        echo "$change" | $_tr ':' '\n' | while read -r entry; do
+        for entry in $(echo "$change" | $_tr ':' ' '); do
             [ -z "$entry" ] && continue # Skip empty entries
             [ -d "$entry" ] || continue # Skip non-existent directories
             temp_entries="$temp_entries:$entry"
@@ -94,15 +96,16 @@ modify_env_path() {
         entries="${temp_entries#:}:$entries"
         ;;
     append)
-        echo "$change" | $_tr ':' '\n' | while read -r entry; do
+        for entry in $(echo "$change" | $_tr ':' ' '); do
             [ -z "$entry" ] && continue # Skip empty entries
             [ -d "$entry" ] || continue # Skip non-existent directories
             entries="$entries:$entry"
         done
         ;;
     delete)
-        echo "$change" | $_tr ':' '\n' | while read -r entry; do
+        for entry in $(echo "$change" | $_tr ':' ' '); do
             [ -z "$entry" ] && continue # Skip empty entries
+            [ -z "$entries" ] && break  # nothing left to remove
             entries=$(rm_env_path_entry "$entries" "$entry")
         done
         ;;
@@ -112,7 +115,8 @@ modify_env_path() {
         ;;
     esac
 
-    trim "$entries" ":"
+    [ -n "$entries" ] && trim "$entries" ":"
+    echo
 }
 
 prepend_paths="$HOME/.local/bin:$HOME/.cargo/bin:$FLUTTER_HOME/bin:$GOPATH/bin:$KREW_ROOT/bin"