I downloaded the Eclipse setup from their homepage. And I followed the instructions on this page. But I couldn't able to follow the last instruction, which ask me to do so :

/opt/eclipse/eclipse -clean

If do so, I get an error message like this :

sudo: /opt/eclipse/eclipse: command not found

But notably I can see the Eclipse Icon on my Dash Home (if I search for "Eclipse"). But clicking on that icon doesn't open the IDE. Where I'm making the mistake?

And also running this command in terminal :

eclipse

throws this output:

/usr/bin/eclipse: 5: /usr/bin/eclipse: /opt/eclipse/eclipse: Permission denied

Thanks in advance.