Ban process substitution from asdf codebase

lib/commands/command-plugin-update.bash

@@ -10,11 +10,12 @@ plugin_update_command() {
   local gitref="${2:-master}"
   if [ "$plugin_name" = "--all" ]; then
     if [ -d "$(asdf_data_dir)"/plugins ]; then
+      plugins=(find "$(asdf_data_dir)"/plugins -type d -mindepth 1 -maxdepth 1)
       while IFS= read -r -d '' dir; do
         local plugin_name
         plugin_name=$(basename "$dir")
         update_plugin "$plugin_name" "$dir" "$gitref" &
-      done < <(find "$(asdf_data_dir)"/plugins -type d -mindepth 1 -maxdepth 1)
+      done <<< "$plugins"
       wait
     fi
   else

lib/commands/command-reshim.bash

@@ -119,7 +119,19 @@ remove_obsolete_shims() {
   exec_names=$(plugin_executables "$plugin_name" "$full_version" | xargs -IX basename X | sort)
 
   local obsolete_shims
-  obsolete_shims=$(comm -23 <(printf "%s\\n" "$shims") <(printf "%s\\n" "$exec_names"))
+  local formatted_shims
+  local formatted_exec_names
+
+  # comm only takes to files, so we write this data to temp files so we can
+  # pass it to comm.
+  formatted_shims=$(mktemp /tmp/asdf-command-reshim-formatted-shims.XXXXXX)
+  printf "%s\\n" "$shims" > "$formatted_shims"
+
+  formatted_exec_names=$(mktemp /tmp/asdf-command-reshim-formatted-exec-names.XXXXXX)
+  printf "%s\\n" "$exec_names" > "$formatted_exec_names"
+
+  obsolete_shims=$(comm -23 "$formatted_shims" "$formatted_exec_names")
+  rm -f "$formatted_exec_names" "$formatted_shims"
 
   for shim_name in $obsolete_shims; do
     remove_shim_for_version "$plugin_name" "$full_version" "$shim_name"

lib/utils.bash

@@ -662,8 +662,10 @@ preset_versions() {
 }
 
 select_from_preset_version() {
-  shim_name=$1
-  grep -f <(get_shim_versions "$shim_name") <(preset_versions "$shim_name") | head -n 1 | xargs -IVERSION printf "%s\\n" VERSION
+  local shim_name=$1
+  local shim_versions=$(get_shim_versions "$shim_name")
+  local present_versions=$(preset_versions "$shim_name")
+  grep -f "$shim_versions" "$preset_versions" | head -n 1 | xargs -IVERSION printf "%s\\n" VERSION
 }
 
 select_version() {

test/banned_commands.bats

@@ -19,6 +19,8 @@ banned_commands=(
     # echo isn't consistent across operating systems, and sometimes output can
     # be confused with echo flags. printf does everything echo does and more.
     echo
+    # Process substitution isn't POSIX compliant and cause trouble
+    "<("
 )
 
 setup() {