fix: Sed improvements (#1087)

lib/commands/command-help.bash

@@ -14,20 +14,17 @@ EOF
 }
 
 asdf_extension_cmds() {
-  local plugins_path ext_cmd_path ext_cmds plugin
+  local plugins_path plugin_path ext_cmd_path ext_cmds plugin
   plugins_path="$(get_plugin_path)"
-  # use find instead of ls -1
-  # shellcheck disable=SC2012
-  for plugin in $(ls -1 "$plugins_path" 2>/dev/null | sed "s#^$plugins_path/##"); do
-    ext_cmd_path="$plugins_path/$plugin/lib/commands"
-    ext_cmds=$(
-      ls -1 "$ext_cmd_path"/command*.bash 2>/dev/null |
-        sed "s#$ext_cmd_path/##"
-    )
+  for plugin_path in "$plugins_path"/*; do
+    plugin="$(basename "$plugin_path")"
+    ext_cmd_path="$plugin_path/lib/commands"
+    ext_cmds="$(find "$ext_cmd_path" -name "command*.bash")"
     if [[ -n $ext_cmds ]]; then
       printf "\\nPLUGIN %s\\n" "$plugin"
       for ext_cmd in $ext_cmds; do
-        sed "s/-/ /g;s/.bash//;s/command-*/  asdf $plugin/;" <<<"$ext_cmd"
+        ext_cmd_name="$(basename "$ext_cmd")"
+        sed "s/-/ /g;s/.bash//;s/command-*/  asdf $plugin/;" <<<"$ext_cmd_name"
       done | sort
     fi
   done

lib/utils.bash

@@ -289,7 +289,7 @@ get_executable_path() {
   check_if_version_exists "$plugin_name" "$version"
 
   if [ "$version" = "system" ]; then
-    path=$(sed -e "s|$(asdf_data_dir)/shims||g; s|::|:|g" <<<"$PATH")
+    path=$(remove_path_from_path "$PATH" "$(asdf_data_dir)/shims")
     cmd=$(basename "$executable_path")
     cmd_path=$(PATH=$path command -v "$cmd" 2>&1)
     # shellcheck disable=SC2181
@@ -755,7 +755,7 @@ with_shim_executable() {
 
     run_within_env() {
       local path
-      path=$(sed -e "s|$(asdf_data_dir)/shims||g; s|::|:|g" <<<"$PATH")
+      path=$(remove_path_from_path "$PATH" "$(asdf_data_dir)/shims")
 
       executable_path=$(PATH=$path command -v "$shim_name")
 
@@ -806,3 +806,20 @@ with_shim_executable() {
 
   return 126
 }
+
+substitute() {
+  # Use Bash substituion rather than sed as it will handle escaping of all
+  # strings for us.
+  local input=$1
+  local find_str=$2
+  local replace=$3
+  printf "%s" "${input//"$find_str"/"$replace"}"
+}
+
+remove_path_from_path() {
+  # A helper function for removing an arbitrary path from the PATH variable.
+  # Output is a new string suitable for assignment to PATH
+  local PATH=$1
+  local path=$2
+  substitute "$PATH" "$path" "" | sed -e "s|::|:|g"
+}