HP OpenVMS Systems Documentation
OpenVMS User's Manual
8.18.1 Obtaining Buffer Information
To display more information about the current buffer, enter the SHOW command. The information displayed includes whether the buffer has been modified, in addition to the following:
If more than one buffer is active during an editing session, EVE
prompts you to press the Do key to get information about other buffers.
To delete a buffer, enter the DELETE BUFFER command and specify the name of the buffer you want to delete. If the buffer is empty or unmodified, EVE deletes it. If, however, the buffer has been modified, EVE prompts you for a choice. Note that the buffer name must be typed in full; no abbreviations are allowed. If you are viewing a buffer that you want to delete, EVE replaces the buffer with the oldest buffer existing in the editing session.
The following table lists the choices you can enter:
In the following example, deletion of the modified buffer MYFILE.TXT is requested:
8.18.3 Changing Buffer Status
Use the SET BUFFER command to change the editing status of the buffer; that is, whether the buffer can be modified and whether the buffer will be written to a file after you exit from EVE.
You can specify one of the following SET BUFFER command keywords for each command:
By default, buffer status is set to MODIFIABLE and WRITE, letting you change the contents of a buffer and save the changed buffer in a file.
To change the status of a buffer so that its contents cannot be inadvertently changed, set the buffer to READ_ONLY (which implies unmodifiable) with the following command:
To change the status of a buffer so it becomes a temporary storage area (a "scratchpad"), set the buffer to READ_ONLY and MODIFIABLE with the following commands:
You then can edit the buffer, but it will not be saved when you exit
EVE uses the message window, which appears at the bottom of the screen, to communicate error and informational messages during an editing session. The message window displays the last message in the Messages buffer.
You can display these messages with the BUFFER command. To display the contents of the Messages buffer, press Do and enter the command BUFFER MESSAGES. To return to the buffer you were editing, press Do and enter the BUFFER command followed by the name of the appropriate buffer.
You can also enter the SHOW BUFFERS command to display the buffers you
have created and press the Select key to choose a buffer.
You can use several buffers if you want to edit more than one file or if you want temporary storage areas for manipulating blocks of text. You can use one of the following commands to create a new buffer: GET FILE or OPEN, OPEN SELECTED, or BUFFER.
To create a new buffer with a file that already exists, enter the GET FILE (or OPEN) command and the name of the file you want to copy to the new buffer. You can use the asterisk (*) wildcard character as a substitute for all or some of the characters in the file name and file type. You can use the percent sign (%) wildcard character as a substitute for one character in the file name and file type, and you can use the ellipsis ([...]) wildcard as a substitute for a directory specification.
You can also use the OPEN SELECTED command to create a new buffer as follows:
To put a specific buffer into the current EVE window, enter the BUFFER command and the name of the buffer you want to put in the current window. You cannot use wildcard characters in buffer names. The asterisk (*) and percent sign (%) are treated as literal characters in a buffer name. If the buffer you specify does not already exist, EVE creates a new buffer.
If the specified file exists, EVE reads the contents of the file into a new buffer and displays the buffer in the current window. If there is more than one match for a file specification with a wildcard, EVE displays a list of choices in the $CHOICES$ buffer and prompts you to provide a more complete file specification. EVE will open the first file it matches if you use a search list or an ellipsis ([...]) wildcard. Otherwise, EVE creates an empty buffer and displays the buffer in the current window.
To change the buffer in the current window, press the Do key, type
BUFFER and the name of the buffer you want to display on the screen,
and then press the Enter key. If you forget a buffer name, enter the
SHOW BUFFERS command to display the names of active buffers in your
editing session and specify a buffer with the Select key.
There are four ways to read a file into an EVE buffer:
8.18.7 Writing Files from EVE
To write the contents of the current buffer to a file, enter the WRITE FILE command. You can include a file specification with the WRITE FILE command. If you do not include a file specification, EVE uses the input file specification to write the file. If you created the current buffer with the BUFFER or NEW command, EVE prompts you for a file specification to which it writes the file.
The following example shows how to use the output file associated with the buffer to write a buffer to the file:
8.18.8 Using Windows
During an EVE editing session, the buffer you are editing is displayed on the screen in a window. A highlighted status line appears at the bottom of the window identifying the name, current editing mode, and current direction of the buffer.
Table 8-16 describes EVE keys used to create and manipulate windows.
Table 8-17 describes EVE commands used to create and manipulate windows.
8.18.9 Viewing Two Sections of One Buffer
To view two sections of a file at the same time, use the SPLIT WINDOW command. EVE splits your screen and creates two identical windows. The cursor maintains its position in the buffer but appears only in the bottom window. The buffer name is the same in both status lines.
Displaying two sections of a long file makes moving text within a file efficient. You can select and remove text from one part of the file and insert it into the other. To move the cursor from one window to the other, enter the NEXT WINDOW command.
To remove the second window from the screen and expand the current
window to occupy the whole editing area, press the Do key, enter the
command ONE WINDOW, and press the Enter key.
The following procedure describes how to edit two buffers containing different files:
8.19 Creating a Subprocess
You can create a subprocess to switch between an EVE editing session
and DCL command level without terminating your editing session. To
create a subprocess, enter the SPAWN command. EVE suspends the current
editing session and connects your terminal to a new subprocess. The DCL
prompt ($) appears on your terminal screen.
The most common reasons to spawn a subprocess are to invoke the Mail utility and to run screen-oriented programs, although your subprocess can invoke any OpenVMS utility or execute any DCL command.
To return to your editing session, log out of the subprocess by entering the DCL command LOGOUT. EVE resumes the editing session, and the cursor appears in the location it occupied before you spawned the subprocess. You can also supply a DCL command as a parameter to the SPAWN command to create a specific subprocess.
In the following example, the Mail utility is spawned from EVE:
The prompt for the Mail utility (MAIL>) appears on the screen. When
you exit from Mail, you are automatically logged out of the subprocess
and EVE resumes the editing session.
Rather than spawn a process to use DCL, you can spawn a process for an EVE editing session and then attach to the parent DCL process to use DCL commands and utilities.
When you want to return to the DCL command level, use the EVE command ATTACH to return to the parent process.
To resume your editing session, reconnect to the editing subprocess by using the DCL command ATTACH with the process name of the subprocess.
In the following example, a subprocess is created using the DCL command SPAWN. The SPAWN command creates the subprocess SMITH_1. At the subprocess level, EVE is invoked and the editing session is conducted. At the end of the editing session, the ATTACH command is entered and you are returned to DCL. Then, to resume the editing session,the DCL command ATTACH is entered using the the process name of the subprocess SMITH_1:
$ define sortshr sys$library:hypersort.exe
To return to SORT/MERGE, deassign SORTSHR. The SORT/MERGE utility is the default if SORTSHR is not defined.
Memory allocation differences may limit the high-performance Sort/Merge utility's ability to perform the same number of concurrent sort operations as the Sort/Merge utility can perform in the same amount of virtual memory.
If this situation occurs, you can either increase the amount of virtual memory that is available to the process, or reduce the working set extent. For information on using system parameters to change the amount of virtual memory or reduce the working set extent, refer to the OpenVMS System Management Utilities Reference Manual.
The behavior of the high-performance Sort/Merge utility is the same as SORT/MERGE, except as shown in Table 9-1.
If you attempt to use an unsupported qualifier or assign an unsupported value to a qualifier, the high-performance Sort/Merge utility generates an error.
|Feature||High-Performance Sort/Merge Behavior|
|Key data types||
The H-FLOATING and ZONED decimal data types are not supported.
The size of a BINARY data type key must be 1, 2, 4, or 8 bytes. A 16-byte binary key is not supported. (Implementation of this feature is deferred to a future OpenVMS Alpha release.)
The National Character Set (NCS) collating sequences are not supported.
(Implementation of this feature is deferred to a future OpenVMS Alpha
release.) Do not specify the name of an NCS collating sequence for the
/COLLATING_SEQUENCE qualifier. The ASCII, EBCDIC, and MULTINATIONAL
collating sequences are supported. The default is ASCII.
You cannot define or modify your own collating sequence through the use of a specification file. (Implementation of this feature is deferred to a future OpenVMS Alpha release.)
|Specification files||Specification files are not supported. (Implementation of this feature is deferred to a future OpenVMS Alpha release.) Do not use the /SPECIFICATION qualifier.|
|Internal sorting process||Only the record sort process is supported. (Implementation of this feature is deferred to a future OpenVMS Alpha release.) You can specify /PROCESS=RECORD or omit the /PROCESS qualifier. The TAG, ADDRESS, and INDEX values for the /PROCESS qualifier are not supported.|
|Statistical summary information||
The following statistics are currently supported:
The following statistics are unavailable:
Full implementation of this feature is deferred to a future OpenVMS Alpha release.