OpenVMS User's Manual
3.6.4 Conflicting Qualifiers
If you use two or more contradictory qualifiers on a command line, the
right-most qualifier overrides the others.
Some commands contain conflicting qualifiers that cannot be specified
in the same command line. If you use incompatible qualifiers, the
command interpreter displays an error message.
Following is an example of conflicting qualifiers. Note that the PRINT
command accepts only the /COPIES=2 and the /NOBURST qualifiers because
they are the right-most qualifiers in the command line:
$ PRINT MYFILE/COPIES=3/BURST/COPIES=2/NOBURST EARTH.TXT
3.6.5 Values Accepted by Qualifiers
Qualifiers can accept keywords, file specifications, character strings,
and numeric values. When you enter a value for a qualifier, separate
the qualifier and the value with either an equal sign (=) or a colon
Some qualifier keywords require additional information. In these cases,
separate the keyword from its value with a colon or an equal sign.
To specify multiple keywords that require values, enclose the list in
parentheses and separate the keyword and value with either an equal
sign (=) or a colon (:).
- Either command in this example is valid:
$ PRINT/COPIES=3 MYFILE.DAT
$ PRINT/COPIES:3 MYFILE.DAT
- This is an example of a qualifier that requires additional
information; the keyword "PROTECTION" is separated from its value by a
colon or an equal sign (=):
$ SET SECURITY/PROTECTION:GROUP:RW MYFILE.DAT
$ SET SECURITY/PROTECTION=GROUP=RW MYFILE.DAT
- This is an example of a qualifier that requires multiple keywords,
each of which require multiple values:
$ SET SECURITY/PROTECTION=(OWNER=RWD,GROUP=RW) myfile.dat
$ SET SECURITY/PROTECTION=(OWNER:RWD,GROUP:RW) myfile.dat
3.7 Entering Dates and Times as Values
Certain commands and qualifiers (such as the PRINT/AFTER command)
accept date and time values. You can specify these values in one of the
- Absolute time
- Delta time
- Combination time (combines absolute and delta time formats)
3.7.1 Absolute Time Format
Absolute time is a specific date or time of day. The format for
absolute time is as follows:
The fields are as follows:
Day of the month: an integer in the range 1 to 31
Month: JAN, FEB, MAR, APR, MAY, JUN, JUL, AUG, SEP, OCT, NOV, or DEC
Year: an integer
Hour: an integer in the range 0 to 23
Minute: an integer in the range 0 to 59
Second: an integer in the range 0 to 59
Hundredths of a second: an integer in the range 0 to 99
The following rules apply when specifying absolute time:
- You can truncate the date or the time on the right.
- If you specify both a date and a time, include a colon between them.
- The date must contain at least one hyphen.
- You can omit any of the fields within the date and time as long as
you include the punctuation marks that separate the fields.
- A truncated or omitted date field defaults to the corresponding
fields for the current date.
- A truncated or omitted time field defaults to zero.
- If you specify a past time in a command that expects the current or
a future time, the current time is used.
You can also specify an absolute time as one of the following keywords:
The current day, month, and year at 00:00:00.0 o'clock
00:00:00.00 o'clock tomorrow
00:00:00.00 o'clock yesterday
The following table shows examples of absolute time specifications:
1 P.M. on December 11, 1999
Midnight at the beginning of December 11 this year
3:30 P.M. today
Midnight on the 19th day of the current year and month
12:30 A.M. on the 19th of this month
3.7.2 Delta Time Format
Delta time is an offset (a time interval) from the current date and
time to a time in the future. The general format of a delta time is as
The fields are as follows:
Number of days; an integer in the range 0 to 9999
Number of hours; an integer in the range 0 to 23
Number of minutes; an integer in the range 0 to 59
Number of seconds; an integer in the range 0 to 59
Number of hundredths of seconds; an integer in the range 0 to 99
If a qualifier is described as a value that can be expressed as an
absolute time, a delta time, or a combination of the two, you must
specify a delta time as if it were part of a combination time. For
example, to specify a delta time value of five minutes from the current
time, use "+:5" (not "0-0:5").
The following rules apply when specifying delta time:
- You can truncate a delta time on the right.
- If you specify the number of days, include a hyphen.
- You can omit fields within the time as long as you include the
punctuation that separates the fields.
- If you omit the time field, the default is zero.
The following table shows some examples of delta time specifications:
3 days from now (72 hours)
3 hours from now
30 minutes from now
3 days and 30 minutes from now
15 hours and 30 minutes from now
3.7.3 Combination Time Format
To combine absolute and delta times, specify an absolute time plus or
minus a delta time. Use one of the following formats:
"[absolute time][+delta time]"
[absolute time][-delta time]
The variable fields and default fields for absolute and delta time
values are the same as those described in the preceding sections.
The following rules apply when specifying combination time:
- Precede the delta time value by a plus or minus sign. (Note that
the minus sign is the same keyboard key as the hyphen.)
- Enclose the entire time specification in quotation marks if a plus
or minus sign precedes the delta time value.
- Omit the absolute time value if you want to offset the delta time
from the current date and time.
- Specify date and time information as completely as possible.
The following table shows some examples of combination time
5 hours from now.
Current time minus 1 hour. The minus sign (-) indicates a negative
offset. (The 1 is interpreted as an hour, not a day, because it is not
followed by a hyphen.)
5 minutes from now.
Current time minus 5 minutes.
Current time minus 1 day. The minus sign (-) indicates a negative
offset. The hyphen (-) separates the day from the time field.
12:05 A.M. on December 31 of the current year. The absolute time
specification (before the colon) defaults to midnight on December 31 of
the current year. The plus sign (+) indicates a positive offset.
11:50 P.M. on December 30 of the current year. The absolute time
specification (before the colon) defaults to midnight on December 31 of
the current year. The minus sign (-) after DEC: indicates a negative
3.8 Recalling Commands
At the DCL prompt, you can recall previously typed command lines to
avoid retyping long command lines. Once a command is displayed, you can
reexecute or edit it.
On OpenVMS VAX systems, the recall buffer holds up to 20 previously
On OpenVMS Alpha systems, the recall buffer holds up to 254 previously
You can display your previously entered commands by using one of the
- Pressing Ctrl/B
- Using up arrow and down arrow keys
- Using the RECALL command
3.8.1 Pressing Ctrl/B
Pressing Ctrl/B once recalls the previous command line. Pressing Ctrl/B
again recalls the line before the previous line and so on to the last
saved command line.
3.8.2 Using Arrow Keys
Using the up arrow and down arrow keys recalls the previous and
successive command, respectively. Press the arrow keys repeatedly to
move through the commands.
3.8.3 Using the RECALL Command
To examine previously typed command lines, type RECALL/ALL. After
reviewing the available commands, you can recall a particular command
line by typing RECALL and the number of the desired command.
You can also follow RECALL with the first characters of the command
line you want to display. RECALL scans the previous command lines
(beginning with the most recent one) and returns the first command line
that begins with the characters you typed.
- This is a sample display generated by typing RECALL/ALL:
1 SET DEFAULT DISK2:[MARSHALL]
2 EDIT ACCOUNTS.COM
3 PURGE ACCOUNTS.COM
4 DIRECTORY/FULL ACCOUNTS.COM
5 COPY ACCOUNTS.COM [.ACCOUNTS]*
6 SET DEFAULT [.ACCOUNTS]
- The following example shows how to recall the fourth command line:
After you press Return, the system displays the fourth command in
the list at the DCL prompt. (The RECALL command itself is not placed in
- The following example shows how to recall a previously entered
command, EDIT ACCOUNTS.COM:
After you press Return, the system displays the following command
If you are running a utility or an application program that uses
OpenVMS screen management software, you can use Ctrl/B and the up arrow
and down arrow keys to perform command recall; however, line editing
must be enabled. Some utilities that have this feature are Mail,
OpenVMS Debugger, Show Cluster, the System Dump Analyzer (SDA), and the
To erase the contents of the recall buffer, enter the RECALL command
with the ERASE qualifier. For example:
For security reasons, it is good practice to erase the contents of the
recall buffer after you have entered commands that include passwords.
3.9 Editing the DCL Command Line
At the DCL command level, you can use many individual keys and key
sequences to change what you type. Although different types of
terminals have different operating characteristics, most have standard
function keys and keys that can be used with line
3.9.1 SHOW TERMINAL Command
To see whether line editing is enabled on your terminal, enter the SHOW
TERMINAL command. The current status of line editing is displayed in
the first column under Terminal Characteristics.
In the following example, line editing is not enabled:
$ SHOW TERMINAL
Terminal: _VTA130: Device_Type: VT200_Series Owner: ROHBA
LAT Server/Port: L121/Port_3
Physical terminal: _LTA130:
Input: 9600 LFfill: 0 Width: 80 Parity: None
Output: 9600 CRfill: Page: 24
Interactive Echo Type_ahead No Escape
No Hostsync TTsync Lowercase Tab
Wrap Scope No Remote No Eightbit
Broadcast No Readsync No Form Fulldup
No Modem No Local_echo No Autobaud Hangup
No Brdcstmbx No DMA No Altypeahd Set_speed
No Line Editing Insert editing No Fallback No Dialup
No Secure server Disconnect No Pasthru No Syspassword
No SIXEL Graphics No Soft Characters No Printer Port Numeric Keypad
ANSI_CRT No Regis No Block_mode Advanced_video
No Edit_mode DEC_CRT No DEC_CRT2
3.9.2 SET TERMINAL Command
You can use the SET TERMINAL command to alter the way in which your
terminal edits a DCL command line. By default, changes made with the
SET TERMINAL command apply only to the current session. To set the
terminal each time you log in, you can include SET TERMINAL commands in
your LOGIN.COM file.
To enable line editing, enter the SET TERMINAL/LINE_EDIT command:
SET TERMINAL/INSERT and SET TERMINAL/OVERSTRIKE
You can edit a command line in either insert or overstrike mode. In
insert mode, the character you type is inserted to the left of the
cursor. In overstrike mode, the character you type
overwrites the character indicated by the cursor.
To change editing modes for a single command line, press Ctrl/A (Ctrl/A
acts as a toggle). To change edit modes for your session, enter either
the SET TERMINAL/INSERT or SET TERMINAL/OVERSTRIKE command.
If you use the SET TERMINAL/WRAP command, when you enter more
characters than will fit on one line of the terminal screen, the text
wraps to the next line. If you use the SET TERMINAL/NOWRAP command,
when you enter more characters than will fit on one line of the
terminal screen, the terminal types over the last character on the line.
You can edit only the line where your cursor appears. When text wraps,
you cannot use the up arrow key to move the cursor up to edit the
previous line. To move the cursor up to the previous line, use the
Delete key and delete all the characters in the current line.
3.9.3 Deleting Portions of the Command Line
The Delete key on your keyboard is marked with either the word Rubout,
the word Delete, or an X in a left-pointing arrow, depending on the
type of terminal you are using. The Delete key back spaces over the
most recently entered character and deletes it. On a hardcopy
terminal, the deleted letters are displayed between backslash
characters so you can see what is being deleted. On a video display
terminal, pressing the Delete key erases the character from the screen
and moves the cursor backwards.
In contrast, the Backspace key (or the left arrow key) back spaces over
characters but does not delete them.
If line editing is enabled, you can use Ctrl/U to delete characters
from the beginning of the line to the current cursor position. If line
editing is not enabled, you can use Ctrl/U to cancel an entire line.
The system ignores the line and redisplays the DCL prompt.
3.10 Defining Terminal Keys
A key definition is a string of characters that you assign to a
particular terminal key. When a key is defined, you can press it
instead of typing the string of characters. A key definition usually
contains all or part of a command line. Using key definitions, you can
customize your keyboard so that you can enter DCL commands with fewer
keystrokes. When you press a defined key, the system either displays
the command on your terminal or executes the command, depending on
whether the command was defined using the /TERMINATE qualifier.
Some definable keys are automatically enabled for definition (for
example, keys PF1 to PF4 and keys F17 to F20 on LK201 keyboards).
However, before you can define other keys, including KP0 (keypad 0) to
KP9 and the keypad keys period, comma, minus, and Enter, you must
enable them for definition by entering either the SET
TERMINAL/APPLICATION_KEYPAD or the SET TERMINAL/NONUMERIC command.
3.11 Summary of Key Sequences
The following sections describe keys and key sequences that you can use
to perform specific operations.
3.11.1 Keys That Enter DCL Commands
The following keys enter DCL commands:
- Ctrl/Z and F10
Signals the end of the file for data entered
from the terminal. Ctrl/Z displays as Exit. This key is available only
on an LK201 keyboard.
Sends the current line to the system for processing.
On some terminals, the Return key is labeled CR. If you are not already
logged in, Return initiates a login sequence.
3.11.2 Keys That Interrupt DCL Commands
The following keys interrupt DCL commands:
- Ctrl/C and F6
During command entry, cancels command
processing. Ctrl/C displays as Cancel. This key is available only on an
Momentarily interrupts terminal output to display a
line of statistical information about the current process. This display
includes your node and user name, the time, the name of the image you
are running, and information about system resources used during your
current terminal session.
You can also use Ctrl/T to determine
whether the system is operating. Ctrl/T does not return information if
the system is temporarily unresponsive or if your terminal is set to
NOBROADCAST. To use Ctrl/T, you must first enter the SET CONTROL=T
command (in the system login command procedure, in your personal login
command procedure, or interactively).
Interrupts command processing. Ctrl/Y displays as
Interrupt. You can disable Ctrl/Y with the command SET NOCONTROL=Y.
Under most conditions, Ctrl/Y returns you to the DCL prompt. The
program running is still active. You can enter any built-in command
then continue the program with the CONTINUE command. (Press Ctrl/W to
refresh the screen after you enter the CONTINUE command.)