Working With SAS on Columbia Unix Server

I’m taking two courses that use SAS this semester because SAS is rather widely used in industry. But it’s expensive and few students taking the same classes ever talked about buying the licence. So I have to use SAS on unix server, and this is rather painful experience.

1. SSH into unix server is not a problem, but Kerberos authentication keeps asking for password whenever a connection is made, which means when SSH into the unix server and exchanging files between remote and local. having to type password over and over again is nightmare.
2. SAS version on unix server is quite old, 9.1.3 compared to 9.2 in computer labs.
3. the GUI of SAS unix can be launched by ssh -X, but it depends on the xserver of local, and I don’t like the experience.
4. some command line options better be added when running SAS on remote, to suppress unnecessary logging.
5. the SAS licence own by Columbia is expiring in about a month, SAS keeps popping warning messages in log file and there is no way to suppress them.

To address problem 1, solution I found so far is to obtain a Kerberos ticket valid for 10 hours so one does not have to enter password for a period of time, but it’s not a thorough solution due to the nature of Kerberos, there’s no way to avoid entering password forever.

The following is only tested on Mac OS X 10.8.2, solution should be similiar on Unix/Linux machines.

$ scp [uni]@cunix.cc.columbia.edu:/etc/krb5.conf ~/

$ sudo mv ~/krb5.conf /etc/
$ sudo vim /etc/krb5.conf
    # add the following in [libdefaults] section
    forward = true
    forwardable = true
    renewable = true
  :wq

$ vim ~/.ssh/config
    # add the following lines
    GSSAPIAuthentication yes
    GSSAPIDelegateCredentials yes
  :wq

$ kinit [uni] # enter password
$ klist # to check ticket status
$ ssh [uni]@cunix.cc.columbia.edu # should connect without prompting password

To make life easier, add some shortcuts

$ vim ~/.bashrc
    alias cussh='ssh [uni]@cunix.cc.columbia.edu'
    export unixhome=[uni]@cunix.cc.columbia.edu:[$home location]
  :wq

# login to remote server
$ cussh
# uploading
$ scp [local files] $unixhome/[remote location]
# downloading
$ scp $unixhome/[remote files] [local]

Each ticket is only valid for 10 hrs, which is a parameter set on Kerberos server. Ticket can be renewed before expiration by

$ kinit -R

Ref & further info:

• Kerberos doc
• Kerbenize ssh client
• kinit automatically when necessary
• Kerberos with PAM under Lion

For problem 2 and 3, stop by computer labs to use SAS 9.2 on Windows machine with GUI.

Some options to supply on command line:

sas -nodms -nonews [program.sas]

Other options to put in *.sas file:

options nodate nonumber nocenter ls=70 ps=80;

As for problem 5, hopefully Columbia will upgrade SAS to 9.2 or 9.3. Just see what happens.