• Entering DCL Commands
• Some Common DCL Commands
• DCL Symbols
• Logical Names
• Customizing Your DCL Environment

$ [label:] verb [/qualifiers] [parameters] [/qualifiers] 

The dollar sign ($) is the default DCL prompt; it will appear whenever DCL is ready to process a command. In the following examples, you don't need to type the $ as part of the command.

The notation [] indicates optional command components. Labels are used in conjunction with command procedures, which are described later in this guide.

DCL is, by default, case-insensitive since it converts text to uppercase before parsing it. Commands can appear in uppercase, lowercase, or mixed-case. For example, the following commands are all equivalent:

$ EDIT TEST.TXT
$ edit test.txt
$ EdIt TeSt.TxT

Verbs and parameters are separated by whitespace, which can be any number of tabs or spaces.

The double-quote character (") is used to override uppercase translation. Text that appears in double quotes is not translated to uppercase and is treated as one syntactic unit. This means that it is possible to specify values that use mixed case and have multiple words. The following commands demonstrate uses of the double-quote character:

$ SEARCH TEST.TXT "Mixed-case words"
$ SET PROCESS/NAME="Process name"

DCL command verbs can be abbreviated to the fewest number of characters that still result in a unique command---the commands BASIC and BACKUP can only be shortened to BAS and BAC, because B and BA are ambiguous commands. Currently, any command requires at most four characters.

2.1.1 Qualifiers and Parameters

$ COPY TEST.TXT TEST1.TXT

• Command qualifiers are used to modify the verb and may appear anywhere on the command line.
• Positional qualifiers are used to modify either the verb or particular parameters, depending on their location on the command line. If a positional parameter follows the verb, it modifies the verb; if it follows a parameter, it affects only that parameter.
• Parameter qualifiers must immediately follow the parameter to be affected.

Most qualifiers are command qualifiers; the on-line help for each command will identify positional and parameter qualifiers.

COPY has a number of qualifiers that can be given. One of these is /LOG, which tells COPY to print an informational message for each file copied. /LOG is an command qualifier, so it can appear anywhere on the command line. For example, the following commands all produce the same results:

$ COPY/LOG TEST.TXT TEST1.TXT
$ COPY TEST.TXT/LOG TEST1.TXT
$ COPY TEST.TXT TEST1.TXT/LOG

An example of a positional qualifier is /COPIES for the PRINT command. If /COPIES follows the verb, it applies to all of the files to be printed; if it follows one of the parameters, it applies only to that parameter. The following commands do not produce the same results:

$ PRINT/COPIES=2 TEST.TXT,TEST1.TXT
$ PRINT TEST.TXT/COPIES=2,TEST1.TXT

In the second example, only one copy of TEST1.TXT would be printed, because /COPIES was positioned after TEST.TXT and therefore applied only to TEST.TXT.

For many commands, you can negate qualifiers by prepending NO to the qualifier. For example, you can specify COPY/NOLOG to prevent COPY from printing the informational messages (the default is /NOLOG).

Some qualifiers accept, or require, a value. For example, the /QUEUE qualifier for the PRINT command requires that you specify the name of a print queue if you wish to print to something other than your default printer. This value is supplied by adding =value to the qualifier name:

$ PRINT TEST.TXT/QUEUE=STH

Multiple values would be enclosed in parentheses and separated by commas:

$ DELETE/ENTRY=(34,35)

$ COPY  <RETURN>
_From: TEST.TXT  <RETURN>
_To: TEST1.TXT  <RETURN>

Because the source and destination were left off the command line, DCL prompted for each (_From: and _To:). The underscore (_) preceding the prompt indicates that the prompt is a continuation of the command line. When DCL is prompting for parameters, it will prompt for optional parameters too. If you don't want to provide the optional parameter, just press Return and DCL will move on to the next parameter, if there is one. If you press Return for a required parameter, DCL will simply re-prompt for that parameter:

$ COPY
_From: <RETURN>
_From: TEST.TXT  <RETURN>
_To: <RETURN>
_To: TEST1.TXT  <RETURN>

You can abort the command at any prompt by typing Ctrl-Z.

Obviously, command prompting is useful for those commands with which you are not very familiar---you can let DCL help you out by telling you what it expects.

2.1.3 Continuation Lines

$ COPY -  <RETURN>
_$ TEST.TXT -  <RETURN>
_$ TEST1.TXT  <RETURN>
$

The continuation character is useful for long commands that extend past the width of the screen. The command line is easier to read when you continue it.

2.1.4 Command Line Editing

Table 2-1 describes each of the line editing keys.

Table 2-1 Line Editing Keys

Key	Effect
Ctrl-A	Toggle between Insert and Overstrike modes. Changing modes with Ctrl-A affects the current line only. Use SET TERMINAL/INSERT or /OVERSTRIKE to change modes for more than one line.
Ctrl-B	Recall previous commands.
Ctrl-C	Cancel the current operation within a program. From the DCL prompt, Ctrl-C cancels the current command line.
Ctrl-D	Move the cursor left by one character.
Ctrl-E	Move the cursor to the end of the line.
Ctrl-F	Move the cursor right by one character.
Ctrl-H	Move the cursor to the beginning of the line.
Ctrl-I	Tab
Ctrl-J	Erase the word preceding the cursor.
Ctrl-M	Return
Ctrl-R	Refresh the command line.
Ctrl-U	Erase from the cursor to the beginning of the line.
Ctrl-X	Erase to the beginning of the line and purge the typeahead (the characters that have been typed but have not been displayed on the screen yet)
Ctrl-Y	Interrupt the execution of the current program. Ctrl-C and Ctrl-Y have the same effect from the DCL prompt.
Ctrl-Z	Line terminator (also exits most applications).

2.1.5 Recalling and Editing Previous Commands

$ SET TERMINAL/LINE_EDITING

To disable line editing, simply specify /NOLINE_EDITING.

There are two qualifiers you can provide to specify the editing mode: /OVERSTRIKE, which causes typed characters to be written over the character under the cursor, and /INSERT, which causes typed characters to be inserted before the cursor. /OVERSTRIKE is the default. As noted above, Ctrl-A is used to toggle between insert and overstrike modes. Ctrl-A toggling only affects the current command line.

2.1.5.2 The RECALL Command

$ RECALL/ALL
 1 dir
 2 edit tmp.tmp
 3 copy/nolog test.txt test1.txt
$

Note that the RECALL command itself does not appear in the command recall buffer. You can recall a particular command in the recall buffer by specifying the command number as a parameter to RECALL:

$ RECALL 3
$ copy/nolog test.txt test1.txt

In addition to providing a command number, you can specify a substring that is used to locate a command. The first command located that begins with the specified substring is then displayed:

$ RECALL COPY
$ copy/nolog test.txt test1.txt

For security purposes, you can erase your command recall buffer with the command RECALL/ERASE.

2.2 Some Common DCL Commands

Table 2-2 provides a brief description of some basic commands. Some of the commands are described elsewhere in this guide; on-line help is available for all of them.

Table 2-2 Basic DCL Commands

HELP	Access the on-line help
SHOW USERS	Show all users currently logged in
SHOW TIME	Show the current date and time
SHOW QUOTA	Show amount of disk quota used
SET PROMPT	Set the DCL prompt
SET PASSWORD	Change your account's password
SET PROCESS	Change various process settings
SHOW PROCESS	Show process information
DEFINE/KEY	Define a key to execute a command
SET TERMINAL	Change terminal settings
SHOW TERMINAL	Show the current terminal characteristics
SHOW SYMBOL	Show DCL symbol definitions
DEFINE	Define a logical
SHOW LOGICAL	Show logical definitions

2.2.1 SET PASSWORD

To change your password, type SET PASSWORD at the DCL prompt. You will be prompted to enter your old password, a new password, and a verification of your new password. The following example shows the prompts:

$ SET PASSWORD
Old password: old-password
New password: new-password
Verification: new-password
$

At the Verification: prompt, simply re-type your new password. The system asks for verification just to make sure that you didn't make a typing error in your password.

Note: For security reasons, the system does not display your passwords. If the new password and its verification do not match, the password is not changed.

The following guidelines should be followed when you choose a new password:

• Avoid names or words that are readily associated with you (your name, username, spouse's name, dog's name, etc.).
• Use at least six characters.
• Mix numbers and letters to make passwords more secure.
• Choose a password that you can remember without writing it down. You could reverse the characters in a string, or use multiple words with no spaces: GONEWITHTHEWIND. It will also help to use a "tweaked" expression like GONEWITHTHEBREEZE.
• Do not tell anyone else what your password is and do not write it down.

If you can't think of a password, SET PASSWORD/GENERATE can be used to generate random "pronounceable" passwords from which you can choose:

$ SET PASS/GENERATE
Old password: old-password
ayxla     ayx-la
taivoa    tai-voa
cawv      cawv
wuiv      wu-iv
tawwia    taw-wi-a
Choose a password from this list, or press RETURN to get a new list
New password: new-password
Verification: new-password
$

Note: Please guard your password carefully---you could be held accountable if another user gains access to your account for any malicious activities.

$ show users
      OpenVMS User Processes at 24-JUN-1996 16:44:21.16 
    Total number of users = 3,  number of processes = 6 
 
 Username      Node     Interactive  Subprocess   Batch 
 COPUSDS       AXP1           2 
 WILLIAMSCA    ALPHA          2 
 WILLIAMSCA    AXP1           1 
 BACKUPS       AXP1           -                     1 
$ 

Interactive jobs are those running from a terminal, subprocesses are children of the interactive jobs, and batch jobs are those processes executing in a batch queue (no terminal is associated with the job).

More detailed information can be displayed by appending the /FULL qualifier to the command:

$ show users/full
      OpenVMS User Processes at 24-JUN-1996 16:46:30.21 
    Total number of users = 3,  number of processes = 6 
 
 Username      Node   Process Name       PID     Terminal 
 COPUSDS       AXP1   COPUSDS          20A016C3  FTA141: 
 WILLIAMSCA    ALPHA  DECW SM          21C00056 
 WILLIAMSCA    ALPHA  Curtis 1         21C0005D  FTA1: 
 WILLIAMSCA    ALPHA  Curtis 2         21C0005E  FTA2: 
 WILLIAMSCA    AXP1   Curtis 3         20A016CA  FTA143: 
 BACKUPS       AXP1   BACKUPS          20A00225  (batch) 
$ 

As you can see, the /FULL display shows each user process and includes the process identification code (PID), the process name, and the terminal associated with the job, if there is one.

Process names can be set using the SET PROCESS/NAME command, described in Section 2.2.4.

You can optionally specify a username or part of a username to match to see if a particular user is logged on. The following example lists all users currently logged-in whose username begins with WILLI:

$ show users willi
      OpenVMS User Processes at 24-JUN-1996 16:53:47.36 
    Total number of users = 2,  number of processes = 6 
 
 Username     Node     Interactive  Subprocess   Batch 
 WILLIJP1     AXP1           1 
 WILLIAMSCA   ALPHA          3           1 
 WILLIAMSCA   AXP1           1 
$ 

$ set prompt="What do you want? "
What do you want? SHOW TIME
   2-AUG-1991 08:59:43
What do you want?

If you don't specify a string, the prompt is changed back to the $.

2.2.4 SET PROCESS

$ SET PROCESS/NAME="Goat Busters"

Process names must be unique within a UIC group.

2.2.5 SET-SHOW TERMINAL

The SET TERMINAL qualifiers /LINE_EDITING, /OVERSTRIKE, and /INSERT have already been discussed. Table 2-3 describes some other useful qualifiers.

Table 2-3 SET TERMINAL Qualifiers

/TYPE=VT200	Define this terminal as one that supports VT200-series features. A VT200-series terminal is necessary to use the certain keys (see Table 2-4 )
/NOBROADCAST	Disable broadcasts (new mail notices, SENDs)
/WRAP	Wrap long lines when TYPEing a file
/NOWRAP	Lines are not to be wrapped
/INQUIRE	Ask terminal what device type it is and modify the terminal settings accordingly
/NONUMERIC	Numeric keypad keys can be defined
/NUMERIC	Numeric keypad keys generate numbers

2.2.6 Defining Keys to Execute DCL Commands

$ DEFINE/KEY key-name "command" [/qualifiers]

The command can be any DCL command (or part of a command); verbs and parameters or qualifiers must be enclosed in quotes. For example, the following example defines PF1 to be SHOW USERS:

$ DEFINE/KEY PF1 "SHOW USERS"/ERASE/TERMINATE

The keys that can be defined include all of the numeric keypad keys, the keys on the editing keypad above the arrow-keys, and the row of function keys along the top of the keyboard. The valid key-names are given in Table 2-4.

Table 2-4 Keys and VT Keyboards

Key Name	VT200-Series	VT100-Series
PF1--PF4	PF1--PF4	PF1--PF4
KP0--KP9	0,1,2,...,9	0,1,2,...,9
Period	.	.
Comma	,	,
Minus	-	-
Enter	Enter	ENTER
Find (E1)	Find	n/a
Insert Here (E2)	Insert Here	n/a
Remove (E3)	Remove	n/a
Select (E4)	Select	n/a
Prev Screen (E5)	Prev Screen	n/a
Next Screen (E6)	Next Screen	n/a
Help	Help	n/a
Do	Do	n/a
F6,F7,...,F20	F6,F7,...,F20	n/a

The keys PF*, F*, E*, Help, and Do are always definable; the numeric keypad keys can only be used when the terminal has been set to use the application keypad (SET TERMINAL/APPLICATION or SET TERMINAL/NONUMERIC ).

Note that the arrow keys and F6--F14 are reserved for line editing. To define these keys, you must set your terminal to /NOLINE_EDITING.

There are several qualifiers you can use with DEFINE/KEY. The two most useful are /ERASE, which erases anything currently on the line, and /TERMINATE, which causes the command to be executed as soon as the key is pressed.

You can also have different key states, so keys can have multiple definitions depending on which key state is active. For more information on key states and the DEFINE/KEY command, see the on-line help or the DCL Dictionary.

The SHOW KEY command can be used to show the current key definitions.

2.3 DCL Symbols

A DCL symbol is defined using the :=, =, :==, or == assignment operators. The format of a symbol definition is:

$ symbol = "Symbol value" 

The operators := and :== let you leave off the double-quotes ("). Using an extra "=" in the operator defines a Global symbol (one that will be accessible from outside a command procedure).

The following example shows the definition of the symbol USE to mean SHOW USERS:

$ USE :== SHOW USERS

USE can now be used to display the users currently logged in.

You can also use symbols to modify standard DCL commands. For example, the following command defines the symbol DIR to mean DIRECTORY/SIZE/DATE:

$ DIR :== DIRECTORY/SIZE/DATE

Now when DIR is typed, the size and creation date of each file will be displayed. Additional DIRECTORY qualifiers can also be specified when the DIR symbol is used:

$ DIR/OWNER

This example is equivalent to the following command:

$ DIRECTORY/SIZE/DATE/OWNER

The DIRECTORY command itself is still available by specifying DIRE (or more letters if desired).

The following syntactic rules are applied to symbols:

• Symbols must begin with the letters A--Z or $.
• Symbol names can also contain numbers, underscore (_), and dash (-) characters.
• Symbol names can be in upper or lower case. However, DCL will translate the symbol name to uppercase before storing a reference in your symbol table.
• Symbols can contain 1-255 characters.

If you want all commands that begin with a certain sequence to perform a particular function, you can use the * character in the name to tell DCL that the remaining characters aren't important. For example, the following symbol definition tells DCL that the full symbol name is DELETE, though any sequence of characters can be specified after DEL:

$ DEL*ETE :== DELETE/LOG

Using the definition above, the following commands are all equivalent to DELETE/LOG TMP.TMP;1:

$ DEL    TMP.TMP;1
$ DELETE TMP.TMP;1
$ DELROY TMP.TMP;1
$ DELA   TMP.TMP;1

Such symbols are useful for powerful commands like DELETE, where you may want to ensure that, for example, /LOG is always applied.

You can look at a symbol definition using the SHOW SYMBOL command. It takes one parameter: the name of the symbol to show. You can use wildcards in the symbol name (wildcards are described in Section 3.1.1).

$ show symbol use
  USE == "SHOW USERS"
$ show symbol u*
  UNIX_COMPRESS == "$WKU$ROOT:[EXE]UNIX_COMPRESS.EXE"
  UNZIP == "$WKU$ROOT:[EXE]UNZIP.EXE"
  USE == "SHOW USERS"
$

Consider, for example, a program that must display data on your terminal. The name of the terminal to use for output could be hardcoded in the program, but then the program couldn't be used from other terminals. Instead, programs usually write to SYS$OUTPUT, which is a logical that is automatically defined to point to your terminal. Similarly, SYS$INPUT is used for input; it, too, is automatically equated to your terminal name when you log in.

Logical names are typically used to provide more "generic" device and directory names. For example, the default user disk is WKU$USER, but this is really just a logical name whose equivalence string is AXP1$DRA2:. Logical names make it easy to, for example, move directories to other disks without impacting applications and users. The user directories could be moved to disk DRA3: and the only other change that would need to be made is to define WKU$USER to point to DRA3:.

Logical names are stored in logical name tables; there are four default tables for every process on the system. Table 2-5 lists them and gives a brief description for each.

Table 2-5 Logical Name Tables

LNM$PROCESS	Logicals available only to one process
LNM$JOB	Logicals available to all processes in a job
LNM$GROUP	Logicals available to all members of a UIC group
LNM$SYSTEM	Logicals defined system-wide for all users

By default, all user logicals are created in the LNM$PROCESS table. You can define a logical using either ASSIGN or DEFINE. The format of the DEFINE command is:

$ DEFINE logical equivalence 

The ASSIGN command reverses the order of the parameters:

$ ASSIGN equivalence logical 

Logical names and equivalences can consist of up to 255 characters. Logical names follow the same naming conventions as files (the conventions are described in Section 3.1, File Specifications).

The following example shows a logical name definition and some commands that use the logical:

$ DEFINE HOME WKU$USER:[USER]   !Define HOME to be WKU$USER:[USER]
$ DIR HOME:                     !Do a directory of WKU$USER:[USER]
$ SET DEFAULT HOME:             !Set default to WKU$USER:[USER]
$ COPY TEST.TXT HOME:           !Copy TEST.TXT to WKU$USER:[USER]

You can look at logicals using the SHOW LOGICAL command. Without any parameters, SHOW LOGICAL shows all logicals defined in the four logical name tables. You can specify a single logical name to check or a wildcarded name:

$ show logical home
   "HOME" = "WKU$USER:[USER]" (LNM$PROCESS_TABLE)
$ show logical SYS$LOGIN*
(LNM$PROCESS_TABLE)
(LNM$JOB_80C04730)
  "SYS$LOGIN" = "WKU$USER:[USER]"
  "SYS$LOGIN_DEVICE" = "WKU$USER:"
(LNM$GROUP_000002)
(LNM$SYSTEM_TABLE)
$

The DEASSIGN command is used to delete a logical name. It accepts the logical name to be deleted as its parameter:

$ DEASSIGN HOME

More information about defining logical names can be found in the on-line help and in the DCL Dictionary.

2.5 Customizing Your DCL Environment

$ @TEST.COM

When you log in, OpenVMS automatically searches for a DCL command procedure called LOGIN.COM in your default login directory (equated to the logical name SYS$LOGIN). If the file exists, it is executed before the DCL prompt is displayed. You can create this file using an editor (described in Chapter 5) or the CREATE command (described in Section 3.2.2).

You can use your LOGIN.COM to customize your DCL environment by including symbol and logical definitions, and commands like SET PROMPT. Each line in the file must be prefixed by a $. The exclamation point (!) is a comment character; if it appears on a line, anything after it is ignored by DCL.

Example 2-1 is a sample LOGIN.COM file that shows some useful symbol definitions you may wish to add your LOGIN.COM. A LOGIN.COM is automatically created the first time you log in to the system. If you do not have a LOGIN.COM, you can copy this template from WKU$ROOT:[SOURCE]LOGIN.TEMPLATE:

$ copy wku$root:[source]login.template sys$login:login.com

Example 2-1 Sample LOGIN.COM Command File

$ sv = 'f$verify(0)'            !Turn off VERIFY mode 
$! 
$!  Define some symbols here 
$! 
$ mail :== mail/edit=(send,forw,reply=extract) !Use editor in MAIL 
$ users :== show users/full      !Make USERS mean SHOW USERS/FULL 
$! 
$!  Define some logicals here 
$! 
$ define home sys$login:         !Make HOME refer to login directory 
$! 
$!  To prevent EVE from confirming whether or not to send a mail 
$!  message (returning to default VMS behavior), remove the "!" 
$!  after the "$" in the line below. 
$! 
$! define hg_eve_skip_mail_confirm true 
$! 
$!  To set your printer default, put the desired queue name in after 
$!  sys$print and remove the ! after the $ (valid queue names are: 
$!  grise, helm, sth2, and tccw). 
$! 
$! define sys$print queue 
$! 
$!  Exit if this is not an interactive session 
$! 
$ if f$mode().nes."INTERACTIVE" then exit 
$! 
$!  To set your process name, which is displayed by SHOW USERS/FULL, 
$!  edit the following line to include the string of your choice and 
$!  remove the "!" after the "$". 
$! 
$! set process/name="Jim Bob" 
$! 
$!  You can define your numeric keypad to execute commands for you. 
$! 
$! set terminal/application             !Enable use of keypad keys 
$! define/key KP0 "USERS"/nolog/erase/termina !0 on keypad is USERS 
$! 
$ exit