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Some unix/linux howto's

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Using the Dept.'s anonymous ftp server
Forwarding X windows through multiple logins
Unix/linux Newbies
Mail Forwarding
Pretty Printing Text Files on Postscript Printers
ssh logins without providing a password
Using the Tape Drive on Wave.met.tamu.edu


How to exchange data with others using anonymous ftp access.

- The Department has a dedicated ftp server for exchange of files and data,
   with a maximum disk capacity of 947 Gigabytes. The host name is:

            ftp.met.tamu.edu

- This server provides

  1. anonymous logins to a protected area for others to both retreive files and data and to deposit files and data. 

    1. ftp access is restricted; currently allowed: local campus and campus vpn, *.nasa.gov, *.noaa.gov, *.edu, *.mcgill.ca, *.nrl.navy.mil, *.agu.org, *.ca.cn, *.edu.cn

    2. Dept. personnel may request additional access from specified hosts/domains (email neils@tamu.edu)

  2. normal ssh and sftp logins for Department accounts -- the same accounts that are on the Rm 1201 LEAP lab machines and the various SGI accounts like nimbus and cg. The users's normal home directory is available upon login.

                                    (plain ftp is NOT available to normal accounts on this server, only ssh and sftp)

Providing your stuff

  1. login to ftp.met.tamu.edu using ssh 

  2. change directory (cd) to /var/ftp/pub

  3. make a directory for you stuff; eg. 'mkdir mydata'

  4. change directory to that directory; eg. 'cd mydata'

  5. copy your stuff into that directory; several ways:

    1. if the stuff is in your home directory, use 'cp' or 'cp -r'

    2. if the stuff is in a non-home directory on another host, use 'scp' or 'scp -r' or sftp.

  6. notify your intended recipient about its availability, giving instruction for them to anonymous ftp to ftp.met.tamu.edu and cd to /pub/mydata

  7. delete your stuff when it is no longer required by the intended party

Instructions for others to send data to you

  1. instruct them to ftp to ftp.met.tamu.edu, providing 'anonymous' as login name (password is not required, but courtesy suggests providing their email address)

  2. change directory (cd) to /incoming

  3. create a directory for their stuff and cd into it

  4. change to binary mode: type 'binary'

  5. use standard ftp commands to 'put' or 'mput' their stuff

  6. you must then retreive their stuff; several convenient ways:

    1. ssh login to ftp, cd /var/ftp/incoming/theirdirectory, and copy their stuff to your home directory

    2. or sftp from your storage host/location of choice to the server, cd to /var/ftp/incoming/theirdirectory, and 'get' or 'mget' their stuff

    3. scp or scp -r their stuff from ftp.met.tamu.edu to your storage host/location of choice

  7. you must notify atmo-unix@tamu.edu when it is OK to delete their stuff from the 'incoming' directory -- you will find that you do not have permission to remove files in 'incoming'. However, be aware that there is an automated purge of files older than 30 days in this 'incoming' directory, so do not assume they will live forever.

  • anonymous users can NOT download data/files from this ftp server's 'incoming' directory

  • so data/files put into 'incoming' are readable only by Department user accounts

Forwarding X windows through multiple login sessions.

Sometimes you may want to log into one machine from your local host, then login from there to another machine, and run an X application (eg. xterm, matlab) on the last machine to display on your local display. This is especially usefull for running X applications on a department host from off campus but to which you have had to connect through another department host which is available for ssh login through the campus firewall. Essentially, you want to channel the X-window through a series of logins back to the host at which you are sitting.

The best way to do this is to make use of the X11-forwarding feature of ssh.

- for unix/linux to unix/linux, force an X11-forwarding request with the '-X' option (capitalized x).

    eg. ssh -X vortex.met.tamu.edu

Confirm at each ssh login that X11-forwarding is correct by looking at the contents of your DISPLAY variable ('echo $DISPLAY'). It should be either "localhost:12.0" or "HOSTNAME:12.0", where '12' actually may be any non-zero number [usually >=10] and 'HOSTNAME' is the name of the host you've logged into (not your local hostname).

If the contents of DISPLAY are not as above, then you've probably got a custom setting of the DISPLAY variable active in your login scripts: .cshrc and .login for csh and tcsh shells, and .profile for sh and ksh shells, and .bashrc for the bash shell. Have a look at these and comment out the setting for the DISPLAY variable by inserting a “#” character as the first charcter on the line. Then log out and log back in.

Some Unix/Linux Newbie Help

A linux tutorial

TAMU Helpdesk Unix commands

A TAMU Unix Intro of limited use - customized for a specific CIS unix computer but interesting anyway.

Some specific tutorials:

The vi editor
Using aliases

Mail Forwarding

Forwarding email from your department accounts is very simple. Your neo account has a few more steps. It is recommended that when you have multiple accounts, forward your mail serially; that is, forward your mail from account1 to account2, then from account2 to account3, and so on. You then can check all mail at the final forwarded destination. If you want to change the final destination,  you only need to change forwarding at the last forwarding point. But you can, of course, configure forwarding any way you wish.
Your Department account(s)
To forward email, create a file in the top level of your home directory (where you are when you first log in) called .forward. Note: this filename begins with a period (.). Add the email address you want to forward to in this file using your favorite text editor; eg., pico, vi, emacs, nedit, gedit. If you've not created a .forward file before, you can create it and insert the forwarding address all in one commandline action:
   cat username@hostname.domain.name > .forward
(This will also overwrite an existing .forward file, which you may at times want to do anyway.)

Most everyone has at least two accounts in the department. One I'll call the SGI/linux account (including the computers in the linux computer lab Rm 1201)and the other the ariel account (ariel.met.tamu.edu), the defacto department mail server. A feature of most of the unix/linux computers in the department is that they share the same home directory. When you login, you see the same files and directories. These shared home directories are /g/h for  the SGI/linux account, and /u for the ariel account.
(Determine where you home directory is when you login by issuing the 'pwd' command. If it contains /g/h/ as part of the file path, then your home directory is the shared filesystem for the SGI/linux account.)
So if you create a .forward in your home directory on that machine, it is also in your home directory on all other unix/linux machines that share the same home directory --- you only have to create this file once for machines that share the same home directory and that forwarding is in effect for all those hosts.

If your 'pwd' shows your home directory is not /g/h (for the SGI/linux accounts) or /u (for the ariel accounts), then you want to make sure you create a .forward in your home directory for that machine, too.

Your neo account
Login to your neo account via a web browser at http://neo.tamu.edu.
Select the 'Directory' link at the upper right.
  Select the 'Edit' link towards the upper right.
  Select the radio button for 'is forwarded to' on both the tamu.edu and neo.tamu.edu sections and put the forwarding
  address in the text box provided.

Be sure you haven't forwarded to a destination that is itself forwarded back to neo. That's a loop that won't go anywhere.






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