Introduction to Unix at site Origin (origin.ea.com)
These are explanations of notes posted to users at login via /etc/motd.
The most recent messages are listed first.
Most information is now on the internal web rather than in this file.
Mon Feb 6 11:34:58 CST 1995
Traditional Unix umask restored; sharing of files must now be explicit.
Subtopics: overview, umask, chgrp, chmod, ls -l (ll), groups.
Persons working together in a group often wish to make files (and even
more often directories) writable to all members of a group. Several
commands relate to this need. In the following, "objects" means a:
"list of names of any filesystem objects, like files, directories, etc".
To see what groups you are in: groups
To see what groups of another user: groups
To see all users in a given group: ypmatch group
To see the groupname on objects: ls -l
To set the groupname on objects: chgrp
To allow group write access to objects: chmod g+w
To disable group write access to objects: chmod g-w
To disable group write on
The alias "ll" has been provided to csh/tcsh users for long listings.
For further information, read the manual pages on:
groups, ls, chgrp, chmod, umask.
The default Umask of 002, allowing basically all users to overwrite
each others files in their home directories, has been changed to the
Unix norm of 022, prevented implicit group sharing of new files. Any
further variations my be set in the ~/.cshrc.mine file.
In anticipation of using shared directories *outside* of users homes
for archiving work to share, the following details on chgrp(1) and
chmod(1) are provided:
Here a long listing (ls -l) of a shared directory of group "wing":
}-2.504-$ mkdir kilrathi
}-2.505-$ chgrp wing kilrathi
}-2.506-$ chmod g+w,+t kilrathi
}-2.508-$ ls -l
drwxrwxr-t 2 joeuser wing 512 Feb 6 14:50 kilrathi
+-write enabled for-+
Anything created within this directory will also belong to "wing".
The "+t" (sticky bit) is supposed to prevent removal of others' files,
except that on IRIX 5.2 it stupidly allows joeuser to anyway, and may
not work correctly over NFS. Just "g+w" is normal sharing, and any
"wing" group member can remove any file.
Use chmod(1) to remove read/write access for anyone else on stuff
like your mail, news, phonelist, etc:
}-2.509-$ chmod go-rw mbox
Also, to add execute permission to a new script you've written:
}-2.510-$ chmod +x ~/bin/netload
Learning Unix, and quirks about Unix at this site.
Subtopics: books, command, defaults, search path, software.
o Books to check out:
Teach Yourself Unix (easy tuturial approach)
Unix for the Impatient (guide/reference, include Emacs and X)
o Commands the beginner should know about:
man, ls, more, emacs/vi, cd, exit, mv, cp, rm, Mail, mkdir, rmdir.
o Commands the beginner should learn next:
ls -la, chmod, groups, chgrp, umask, set, alias, ps, finger, kill.
o Default account setup:
New accounts use the bash(1) and have symbolic links to generic
configuration files which are not writable to the user. The
default umask is 022. Mail is POP-only.
Several aliases are provided, and the dotfiles auto-config
the search path and environment to whichever major software
packages are found on the system. Users begin in group "person"
with no additional groups.
o Search path:
The directory /pod/local/bin, and many others, should be included
in the path automatically by the default startup scripts for the
shells csh and tcsh. They are created from the YP/NIS map named
"auto.pod". This has not yet been generalized to either the
LD_LIBRARY_PATH or MANPATH variables.
o Key services:
SMTP, NNTP, NFS (w/automount), YP/NIS, DNS (primary), X11R6,
SNMP, HTTP, rwhod, timed (to UTC), xdm.
o Key public software and sundry:
GNU, screen, PBM, RFC's, Mosaic, Netscape, HTTPD, IRC (no server),
less, PERL, TCL/TK.
If your passwords are insecure, or missing, run: /pod/local/bin/password
The required way to set your account password within Origin.
Performs exhaustive checks to make sure your password cannot be
These machines crossmount with paths of the form: /on//
This allows you to view files on any of the Unix machines as
though those files all resided on the local host, under a special
pathname starting with /on// . This is implemented via the