Unix for VMS Users

Contents:- File Names Commands in General Basic Commands Editor
The intent of this document is to provide a very quick introduction to Unix operating systems for VAX/VMS users. It is not intended to be comprehensive. It contains just enough information for VMS programmers to get started on the new Linux systems. Much more comprehensive information is available at the Computing Division's Unix at Fermilab web site.

File Names

Unix  /usr/home/username/project/file.typ
Unix  project/file.typ  ./project  ../file.typ
  • File names in Unix are case sensitive.
  • There are no version numbers in Unix.
  • Unix file names do not contain node or device fields.
  • File types are (often) optional in Unix. In particular, directory files do not have an explicit file type.
  • In Unix '.' refers to the current directory and '..' refers to its parent directory.

Commands in General

  • Unix commands are case sensitive.
  • Unix commands cannot be abbreviated.
Some Useful Unix Command Line Editing Keys
KeyResults KeyResults
<Up>  Recall previous command. <Down>  Recall next command.
<Left>  Move cursor left one character. <Right>  Move cursor right one character.
<Bksp>  Delete character to left of cursor. <Del>  Delete character under cursor.
<Ctrl>-a  Move cursor to start of line. <Ctrl>-e  Move cursor to end of line.
<Ctrl>-u  Delete from cursor to start of line. <Ctrl>-k  Delete from cursor to end of line.
<Ctrl>-t  Transpose two characters. <TAB>  Command and filename completion.

Basic Commands

The Unix equivalents of some basic VMS commands
VMS Unix Description
HELP command
man command
apropos topic
Provide help on a command
.. list commands related to 'topic'.
SHOW DEFAULT pwd Show current directory
ls -l
List directory contents
.. with details
cd project
cd ..
cd ~user
Change directory
Move up one directory level
Go to a user's home directory
CREATE/DIRECTORY [.PROJECT] mkdir project Make a new directory
DELETE PROJECT.DIR rmdir project Remove a directory
rm file.typ
rm -i *.typ
Remove a file
.. prompting for confirmation
RENAME OLD.; NEW.; mv old new Rename or move a file
COPY OLD.; NEW.; cp old new Copy a file
cat file.typ
more file.typ *
head file.typ
tail file.typ
Display the file's contents
.. page by page
.. just the beginning
.. just the end
grep -i 'text' file
grep 'Text' file
grep '^Text' file
grep 'Text$' file
grep 'Text.' file
grep 'Text\.' file
Search for "text" in a file
.. case sensitive
.. match lines beginning with "Text"
.. match lines ending with "Text"
.. match "Text" followed by anything
.. match "Text."
DIFFERENCE F1.TYP F2.TYP diff f1.typ f2.typ Display differences
Stop the current process
Suspend the current process
Resume a suspended process
EOF (Terminate input)
*  Type <Enter> for next line, <Space> for next page, and q to quit.


A number of editors are available under unix and users are free to choose whichever one they prefer. However, the defaullt choice is nedit because:-
  • It is intuitive in that it uses normal mouse operations for selectinng text and standard keyboard shortcuts for basic operations (<Ctrl>-c for copy, <Ctrl>-v for paste, <Ctrl>-x for cut, <Ctrl>-s for save, and <Ctrl>-q to quit.)
  • It is easy to use in that all commands are menu driven and there is a built-in help facility.
  • It is quite powerful.
  • It is language sensitive.
  • It is also available on VMS.

User Authentication

Some console applications need to authenticate the user to determine whether the user is authorized to take some privledged actions. For example, edit a device in D80. On VMS this was done by using VMS passwords. Linux use Kerberos. Therefore, the average user does not have an equivalent to their VMS password on Linux. A system for maintaining such applications passwords has been built for Linux. To initialize or change your password:

Setting your console application password on Linux
Action Explanation
Login to a Linux machine, i.e., clxNN. The conpwd command needs the ticket to determine your identity
Type conpwd The conpwd command requires no arguments
Enter the password of your choice twice as prompted There is a five-character minimum

The password established by conpwd unlike your VMS password is not involved with your authentication for access/login to a console machine itself, e.g., cns/clx55. For the access/login to the Linux console system itself Kerberos authentication is used.








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