Update install.command

Update install.command to be compatible with modern Mac versions.

Author: avnikasikci

installation/MacOs/install.command

@@ -1,14 +1,15 @@
 # Simple installation script for MacOS
+kernel=$(uname -s)
 
-if [ $kernel != "Darwin" ]; then
+if [ "${kernel:-}" != "Darwin" ]; then
   echo "Non MacOS System detected, please use the right installtion file for your system"
 else
     DONE_STEPS=0
 
     # Check if Python is installed
-    if command -v python &>/dev/null; then
+    if command -v python3 &>/dev/null; then
         echo "Python is installed"
-        DONE_STEPS=`expr $DONE_STEPS + 1`
+        DONE_STEPS=$((DONE_STEPS + 1))
     else
         echo "Please install the latest version of Python from https://www.python.org/downloads/"
         echo 
@@ -18,22 +19,22 @@ else
     echo "===================="
 
     # Check if pip is installed
-    if command -v pip &>/dev/null; then
+    if command -v pip3 &>/dev/null; then
         echo Pip is installed
-        DONE_STEPS=`expr $DONE_STEPS + 1`
+        DONE_STEPS=$((DONE_STEPS + 1))
     else
         echo "Installing pip..."
         curl https://bootstrap.pypa.io/get-pip.py > get-pip.py
 
         # Asking for PW for user installation
         echo "Please insert your password in order to install pip"
-        sudo python get-pip.py
+        sudo python3 get-pip.py && rm get-pip.py
         rm get-pip.py
 
         # Check if it's installed now
-        if command -v pip &>/dev/null; then
+        if command -v pip3 &>/dev/null; then
             echo "Pip has been successfilly installed"
-            DONE_STEPS=`expr $DONE_STEPS + 1`
+            DONE_STEPS=$((DONE_STEPS + 1))
         else
             echo "Pip could not be installed, please manually install pip using this resource: https://stackoverflow.com/questions/17271319/how-do-i-install-pip-on-macos-or-os-x"
             echo 
@@ -47,7 +48,7 @@ else
     CHROMEPATH="/Applications/Google Chrome.app/Contents/MacOS/Google Chrome"
     if [ -x "$CHROMEPATH" ]; then
         echo "Chrome is installed"
-        DONE_STEPS=`expr $DONE_STEPS + 1`
+        DONE_STEPS=$((DONE_STEPS + 1))
     else
         echo "Please make sure that Chrome is installed. If not, please install the latest version of Chrome from https://www.google.com/chrome/"
         echo 
@@ -64,8 +65,7 @@ else
         echo "===================="
 
         # Checking if it was installed
-        PIP_INSTALLS="$(pip list)"
-        if [[ $PIP_INSTALLS = *"instapy"* ]]; then
+        if pip3 show instapy &>/dev/null; then
             echo "Successfully installed InstaPy!"
         else
             echo "There was a problem installing InstaPy, please copy the error message and create an issue here: https://github.com/InstaPy/instapy-quickstart/issues"