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HP OpenVMS Systems Documentation

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HP OpenVMS DCL Dictionary


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HELP

The HELP command invokes the Help facility to display information about use of the system, including formats and explanations of commands, parameters, qualifiers, and system messages. In response to the Topic? prompt, you can:
  • Type the name of the command or topic for which you need help.
  • Type INSTRUCTIONS for more detailed instructions on how to use HELP.
  • Type HINTS if you are not sure of the name of the command or topic for which you need help.
  • Type /MESSAGE for help with the HELP/MESSAGE utility.
  • Type a question mark (?) to redisplay the most recently requested text.
  • Press RETURN one or more times to exit from HELP.

You can abbreviate any topic name, although ambiguous abbreviations result in all matches being displayed.


Format

HELP [topic[subtopic...]]


Parameter

topic[subtopic...]

Specifies the topics or topic and subtopics on which you want information from a help library.

Description

Information within help libraries is arranged in a hierarchical manner. The levels are as follows:
  1. None---If you do not specify a keyword, the Help facility describes the HELP command and lists the topics that are documented in the root library. Each item in the list is a keyword in the first level of the hierarchy.
  2. Topic-name---If you specify a keyword by naming a topic, the Help facility describes the topic as it is documented in either the root library or in one of the other enabled default libraries. Keywords for additional information available on this topic are listed.
  3. Topic-name subtopic---If you specify a subtopic following a topic, the Help facility provides a description of the specified subtopic.
  4. @filespec followed by any of the previous levels---If you specify a help library to replace the current root library, the Help facility searches that library for a description of the topic or subtopic specified. The file specification must take the same form as the file specification included with the /LIBRARY command qualifier. However, if the specified library is an enabled user-defined default library, the file specification can be abbreviated to any unique leading substring of that default library's logical name translation.

To use the Help facility on OpenVMS in its simplest form, enter the HELP command from your terminal. The Help facility displays a list of topics at your terminal and the prompt Topic?. To see information on one of the topics, type the topic name after the prompt. The system displays information on that topic.

If the topic has subtopics, the HELP command lists the subtopics and displays the Subtopic? prompt. To get information on one of the subtopics, type the name after the prompt. To see information on another topic, press Return. You can now ask for information on another topic when the Help facility displays the Topic? prompt. Press Return to exit the Help facility and return to DCL command level.

If you use an asterisk (*) in place of any keyword, the HELP command displays all information available at the level that the asterisk replaces. For example, HELP COPY * displays all the subtopics under the topic COPY.

If you use an ellipsis (...) immediately after any primary keyword, the Help facility displays all the information on the specified topic and all subtopics of that topic. For example, HELP COPY... displays information on the COPY topic as well as information on all the subtopics under COPY. The ellipsis can only be used from the topic level; it cannot be used from the subtopic level.

The asterisk (*) and the percent sign (%) wildcard characters are allowed in the keyword.


Qualifiers

/EXACT

Use with the /PAGE=SAVE and /SEARCH qualifiers to specify a search string that must match the search string exactly and must be enclosed with quotation marks (" ").

If you specify the /EXACT qualifier without the /SEARCH qualifier, exact search mode is enabled when you set the search string with the Find (E1) key.

/HIGHLIGHT[=keyword]

Use with the /PAGE=SAVE and /SEARCH qualifiers to specify the type of highlighting you want when a search string is found. When a string is found, the entire line is highlighted. You can use the following keywords: BOLD, BLINK, REVERSE, and UNDERLINE. BOLD is the default highlighting.

/INSTRUCTIONS (default)

/NOINSTRUCTIONS

Displays an explanation of the HELP command along with the list of topics (if no topic is specified). By default, the HELP command display includes a description of the facility and the format, along with the list of topics. If you specify the /NOINSTRUCTIONS qualifier, only the list of topics is displayed.

/LIBLIST (default)

/NOLIBLIST

Displays any auxiliary help libraries.

/LIBRARY=filespec

/NOLIBRARY

Uses an alternate help library instead of the default system library, SYS$HELP:HELPLIB.HLB. The specified library is used as the main (root) help library, and is searched for Help facility information before any user-defined default help libraries are checked.

If you omit the device and directory specification, the default is SYS$HELP, the logical name of the location of the system help libraries. The default file type is .HLB.

The /NOLIBRARY qualifier excludes the default help library from the library search order.

/MESSAGE

Displays descriptions of system messages. See the HELP/MESSAGE command in this manual.

/OUTPUT[=filespec]

/NOOUTPUT

Controls where the output of the command is sent. By default, the output is sent to SYS$OUTPUT, the current process default output stream or device.

If you enter the /OUTPUT qualifier with a partial file specification (for example, /OUTPUT=[JONES]), HELP is the default file name and .LIS is the default file type. The asterisk (*) and the percent sign (%) wildcard characters are not allowed.

If you enter the /NOOUTPUT qualifier, output is suppressed.

/PAGE[=keyword]

/NOPAGE (default)

Controls the display of information on the screen.

You can use the following keywords with the /PAGE qualifier:

CLEAR_SCREEN Clears the screen before each page is displayed.
SCROLL Displays information one line at a time.
SAVE[= n] Enables screen navigation of information, where n is the number of pages to store.

The /PAGE=SAVE qualifier allows you to navigate through screens of information. The /PAGE=SAVE qualifier stores up to 5 screens of up to 255 columns of information. When you use the /PAGE=SAVE qualifier, you can use the following keys to navigate through the information:

Key Sequence Description
Up arrow key, Ctrl/B Scroll up one line.
Down arrow key Scroll down one line.
Left arrow key Scroll left one column.
Right arrow key Scroll right one column.
Find (E1) Specify a string to find when the information is displayed.
Insert Here (E2) Scroll right one half screen.
Remove (E3) Scroll left one half screen.
Select (E4) Toggle 80/132 column mode.
Prev Screen (E5) Get the previous page of information.
Next Screen (E6), Return, Enter, Space Get the next page of information.
F10, Ctrl/Z Exit. (Some utilities define these differently.)
Help (F15) Display utility help text.
Do (F16) Toggle the display to oldest/newest page.
Ctrl/W Refresh the display.

The /PAGE qualifier is not compatible with the /OUTPUT qualifier.

/PROMPT (default)

/NOPROMPT

Permits you to solicit further information interactively. If you specify the /NOPROMPT qualifier, the Help facility returns you to DCL command level after it displays the requested information.

If the /PROMPT qualifier is in effect, one of four different prompts is displayed, requesting you to specify a particular help topic or subtopic. Each prompt represents a different level in the hierarchy of help information. The four prompt levels are as follows:

  1. Topic?---The root library is the main library and you are not currently examining the Help facility information for a particular topic.
  2. [library-spec] Topic?---The root library is a library other than the main library and you are not currently examining the Help facility information for a particular topic.
  3. [keyword] Subtopic?---The root library is the main library and you are currently examining the Help facility information for a particular topic (or subtopic).
  4. A combination of 2 and 3.

When you encounter one of these prompts, you can enter any one of the responses described in the following table:

Response Current Prompt Environment Action
keyword[...] 1,2 Searches all enabled libraries for the keyword.
  3,4 Searches additional help libraries for the current topic (or subtopic) for the keyword.
@filespec
keyword[...]
1,2 Same as above, except that the library specified by @filespec is now the root library. If the specified library does not exist, the Help facility treats @filespec as a normal keyword.

Displays a list of topics available in the root library.

  3,4 Same as above; treats @filespec as a normal keyword.

Displays the list of subtopics of the current topic (or subtopics) for which help exists.

[Return] 1 Exits from the Help facility.
  2 Changes root library to main library.
  3,4 Prompts for a topic or subtopic at the next higher level.
[Ctrl/Z] 1,2,3,4 Exits from the Help facility.

/SEARCH="string"

Use with the /PAGE=SAVE qualifier to specify a string that you want to find in the information being displayed. Quotation marks are required for the /SEARCH qualifier, if you include spaces in the text string.

You can also dynamically change the search string by pressing the Find key (E1) while the information is being displayed. Quotation marks are not required for a dynamic search.

/USERLIBRARY=(level[,...])

/NOUSERLIBRARY

Names the levels of search for information in auxiliary libraries. The levels are as follows:
PROCESS Libraries defined at process level
GROUP Libraries defined at group level
SYSTEM Libraries defined at system level
ALL All libraries (default)
NONE No libraries (same as the /NOUSERLIBRARY qualifier)

Auxiliary help libraries are libraries defined with the logical names HLP$LIBRARY, HLP$LIBRARY_1, HLP$LIBRARY_2, and so on. Libraries are searched for information in this order: root (current) library, main library (if not current), libraries defined at process level, libraries defined at group level, libraries defined at system level, and the root library. If the search fails, the root library is searched a second time so that the context is returned to the root library from which the search was initiated. The default is the /USERLIBRARY=ALL qualifier. If you specify only one level for the Help facility to search, you can omit the parentheses.

/WRAP

/NOWRAP (default)

Use with the /PAGE=SAVE qualifier to limit the number of columns to the width of the screen and to wrap lines that extend beyond the width of the screen to the next line.

The /NOWRAP qualifier extends lines beyond the width of the screen and can be seen when you use the scrolling (left and right) features provided by the /PAGE=SAVE qualifier.


Examples

#1

$ HELP
HELP
  .
  .  (HELP message text and list of topics)
  .
Topic?
      

In this example, the HELP command is entered without any qualifiers or parameters. This example produces a display of the help topics available from the root help library, SYS$HELP:HELPLIB.HLB.

If you enter one of the listed topics in response to the Topic? prompt, the Help facility displays information about that topic and a list of subtopics (if there are any). If one or more subtopics exist, the Help facility prompts you for a subtopic, as follows:


Topic? ASSIGN
ASSIGN
  .
  .  (HELP message text and subtopics)
  .
ASSIGN Subtopic?

If you type a subtopic name, the Help facility displays information about that subtopic, as follows:


ASSIGN Subtopic? Name
ASSIGN
  Name
  .
  .  (HELP message text and subtopics, if any)
  .
ASSIGN Subtopic?

If one or more sub-subtopics exist, the Help facility prompts you for a sub-subtopic; otherwise, as in the previous example, the facility prompts you for another subtopic of the topic you are currently inspecting.

Entering a question mark (?) redisplays the Help facility message and options at your current level. Pressing Return does either of the following:

  • Moves you back to the previous help level if you are in a subtopic level.
  • Terminates the Help facility if you are at the first level.

Pressing Ctrl/Z terminates the Help facility at any level.

#2

$ HELP COPY... 
      

The HELP command in this example displays a description of the COPY command and of the command's parameters and qualifiers. Note that the ellipsis can be used only from the topic level; it cannot be used from the subtopic level.

#3

$ HELP/NOPROMPT ASSIGN/GROUP
  .
  .  (ASSIGN/GROUP HELP message)
  .
$
$ HELP/NOPROMPT/PAGE EDIT *
  .
  .  (HELP messages on all first-level EDIT subtopics)
  .
$
      

The two HELP commands request help on specific topics. In each case, the HELP command displays the help message you request and then returns you to DCL command level and the dollar sign prompt ($).

The first command requests help on the /GROUP qualifier of the ASSIGN command. The asterisk (*) in the second example is a wildcard character. It signals the Help facility to display information about all EDIT subtopics, which are then displayed in alphabetical order. The /NOPROMPT qualifier suppresses prompting in both sample commands. The /PAGE qualifier on the second HELP command causes output to the screen to stop after each screen of information is displayed.

#4

$ HELP FILL
Sorry, no documentation on FILL
Additional information available:
 .
 .  (list of first-level topics )
 .
Topic? @EDTHELP FILL
FILL
 .
 .  (FILL HELP message)
 .
@EDTHELP Topic?
 
      

When you enter a request for help on a topic that is not in the default help library, you can instruct the Help facility to search another help library for the topic. In this example, entering the command @EDTHELP FILL instructs the Help facility to search the help library SYS$HELP:EDTHELP.HLB for information on FILL, an EDT editor command. The Help facility displays the message and prompts you for another EDT editor topic.

#5

$ SET DEFAULT SYS$HELP
$ DEFINE HLP$LIBRARY EDTHELP
$ DEFINE HLP$LIBRARY_1 MAILHELP
$ DEFINE HLP$LIBRARY_2 BASIC
$ DEFINE HLP$LIBRARY_3 DISK2:[MALCOLM]FLIP
$ HELP REM
      

You can use logical names to define libraries for the Help facility to search automatically if it does not find the specified topic in the OpenVMS root help library. This sequence of commands instructs the Help facility to search libraries in addition to the default root library, SYS$HELP:HELPLIB.HLB.

The four DEFINE statements create logical names for the four user-defined help libraries that the Help facility is to search after it has searched the root library. The first three entries are help libraries in the current default directory. By default, the Help facility searches for user-defined help libraries in the directory defined by the logical name SYS$HELP. The fourth entry is the help library FLIP.HLB in the directory DISK2:[MALCOLM]. Note that the logical names that you use to define these help libraries must be numbered consecutively; that is, you cannot skip any numbers.

The Help facility first searches the root library for REM. It then searches the libraries HLP$LIBRARY, HLP$LIBRARY_1, HLP$LIBRARY_2, and so on, until it finds REM or exhausts the libraries it knows it can search. When it finds REM in the BASIC.HLB library, the Help facility displays the appropriate help information and prompts you for a subtopic in that library. If you request information on a topic not in the BASIC.HLB library, the Help facility once again searches the help libraries you have defined.


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