functions: update pipupdate

functions.sh

@@ -223,13 +223,32 @@ fi
 
 ### end of mac-specific functions
 
-function pipupdate(){
-    for pip in pip2 pip3; do
-        if [ -z $pip ]; then
-            continue
+pipupdate(){
+    set -x
+    if [[ "$1" == "user" ]]; then
+        user_flags='--user'
+        shift
     fi
-        $pip freeze --local | grep -v '^\-e' | cut -d = -f 1 | xargs -n1 $pip install -U
+    if [[ -n "$@" ]]; then
+        pip="$1"
+        shift
+        flags="$*"
+        echo "pip command is: '$pip $flags'"
+        if ! command -v "$pip" ; then
+            echo "Given command ($1) does not exist." 1>&2
+            return
+        fi
+
+    else
+        pip='python'
+        flags='-m pip'
+        echo "Using default pip: $pip $flags"
+    fi
+
+    for package in $($pip $flags freeze $user_flags --local | grep -v '^\-e' | cut -d = -f 1) ; do
+        $pip $flags install "$user_flags" -U "$package"
     done
+    set +x
 }
 
 # unzip file to directory with the same name of the zip file (without extension)