implement pylist, fixes #2

penv

@@ -19,6 +19,7 @@ usage() {
     # echo " - setdef <name>            - Use an existing environment as the default kernel"
     echo " - activate <name>          - Activates an existing environment (depricated, use pact)"
     echo " - list                     - List available environments"
+    echo " - pylist                   - List available PYTHON versions"
     echo " - install                  - Initialize user's profile"
     echo " - uninstall                - Remove ALL the environments installed using PENV"
     echo " - help                     - Print this message"
@@ -28,6 +29,7 @@ usage() {
     echo " - del      -> rm"
     # echo " - setdef   -> sd"
     echo " - activate -> ac, act"
+    echo " - pylist   -> pyls"
     echo " - list     -> ls"
 }
 
@@ -177,6 +179,10 @@ uninstall() {
     echo "Uninstalled PENV"
 }
 
+pyls(){
+    ls /usr/bin/python3.* /usr/local/bin/python3.* 2> /dev/null | tr " " "\n" | grep "3.*" --color=always
+}
+
 if [ "$#" -lt 1 ]; then
     title
     usage
@@ -201,6 +207,9 @@ case "$cmd" in
     list|ls)
         list
         ;;
+    pylist|pyls)
+        pyls
+        ;;
     help)
         title
         usage