Use ${PWD} instead of $(pwd)

Don't subshell when there's a shell parameter for it.

plugins/available/dirs.plugin.bash

@@ -23,7 +23,7 @@ alias 8="pushd +8"
 alias 9="pushd +9"
 
 # Clone this location
-alias pc="pushd \$(pwd)"
+alias pc='pushd "${PWD}"'
 
 # Push new location
 alias pu="pushd"
@@ -73,7 +73,7 @@ G () {
     example '$ G ..'
     group 'dirs'
 
-    cd "${1:-$(pwd)}" ;
+    cd "${1:-${PWD}}" ;
 }
 
 S () {