environment variable edit error
First check that your path variable is working or not just type (echo $PATH) from terminal it will return the O/P like: /usr/local/bin:/usr/bin:/bin:/usr/sbin:/sbin if saying "commond not found"
Then you have to PATH variable to setup path variable below steps
1) vi /etc/paths it's will vi editor to edit type "I" and enter below mention lines
/usr/local/bin /usr/bin /bin /usr/sbin /sbin
2) press esc and type wq to save exit.