UNIX is an operating system that originated at Bell Labs in 1969 as an interactive time-sharing system. Ken Thompson and Dennis Ritchie are considered the inventors of UNIX. The name (pronounced YEW-nihks) was a pun based on an earlier system, Multiplexed Information and Computing Se. In 1974, UNIX became the first operating system written in the C language. UNIX has evolved as a kind of large freeware product, with many extensions and new ideas provided in a variety of versions of UNIX by different companies, universities, and individuals. More information can be found at http://whatis.techtarget.com/definition/0,289893,sid9_gci213253,00.html.

• What are some common UNIX commands?
• My workstation "froze." What can I do? First of all, NEVER REBOOT A UNIX MACHINE/SUN WORKSTATION. That being said, it is quite an achievement to actually "freeze" a unix workstation, although the causes for an unresponsive box can be numerous. Two major reasons for a freeze, and the means to "defrosting" them are listed below:
  • Excessive Resources Demand: If an application requires the use of multiple CPUs, threads issues may freeze or cause the entire Workstation to become unresponsive. To end the processes that are causing this, you should telnet into the unresponsive Workstation from another machine. To telnet into one machine from another the SIS labs, type "telnet Workstation" (where Workstation represents the "name" of the unresponsive Workstation). Log in using your paradox loginname and password. At the command line, type "ps -flu yourloginname." This will return a list of all of the processes you are running on the unresponsive Workstation. Find the PID (process id circled in the graphic) for the process called "usr/dt/bin/dtsession" (located between the two orange stars in the graphic below).
  • At the command line, type the following to kill (end) your current session on the unresponsive Workstation: "kill -9 PID" (where PID represents the actual process id number, in this case 7420). Almost immediately, the unresponsive Workstation should return to the login screen.
  • Another User: If it appears that your machine is freezing up, or running extremely slowly, you may be sharing your Workstation with a remote user. That user is using processes that are impairing the system's response time. If you believe that this is the case, please let the labs administrator know.
• I rebooted my Workstation and now my password doesn't work at the command line prompt. How do I restart the machine? First of all, NEVER REBOOT A SUN WORKSTATION. The Workstations are protected at the hardware level by firmware, so only a systems administrator with root access can restart them once they have been turned off and on. There is NO reason that anyone but the systems administrator should reboot a Sun Workstation in the SIS Computing Labs. If you see a Workstation that has been rebooted, please alert the GSA on duty.
• More unix help files