Building-from-source.md

+# Building `guiscrcpy` from source.
+## Local build
+Building guiscrcpy locally (user-level), is easier than a system-wide installation
+```bash
+git clone https://github.com/srevinsaju/guiscrcpy.git --depth=1
+cd guiscrcpy
+python3 setup.py install --user
+```
+
+If `~/.local/bin` is not on PATH, add it to your `~/.bashrc`, `~/.zshrc`
+
+
+## System-wide build (Linux only)
+Installing a python package with sudo always messes up the system. As an alternative, as suggested by @tukusejssirs, a possible solution is to install it to the `/opt` on Linux.
+
+```bash
+git clone https://github.com/srevinsaju/guiscrcpy --depth=1
+sudo python3 -m pip install . --prefix=/opt/guiscrcpy
+echo "
+
+TEST_PYTHONPATH=$(grep -c '/opt/lib/python3.8/site-packages' <<< '$PYTHONPATH')
+
+if [ -e /opt/lib/python3.8/site-packages ]; then
+    if [ '$TEST_PYTHONPATH' = '0' ]; then
+	if [ '$PYTHONPATH' ]; then
+	    export PYTHONPATH='$PYTHONPATH:/opt/lib/python3.8/site-packages'
+	else
+	    export PYTHONPATH='/opt/lib/python3.8/site-packages'
+	fi
+    fi
+fi
+"
+>> ~/.bashrc
+```
+
+> NOTE: Use sudo wisely, unless you have a proper reason to install `guiscrcpy` system-wide, DO NOT do it.
\ No newline at end of file