( TM) Beginning to Use DESL : Getting started

Contents :

Running DESL
DESL Modes of Execution
Data Files
General DESL file Access/Creation
Data file Searches

Please take a look at the collection of frequently asked questions. Hopefully most of your questions regarding how to obtain, configure, and use DESL are addressed.

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( TMrun) Running DESL

When either the demonstration or unrestricted version of DESL was downloaded a 16-character password was emailed to the registration email address used after the downloading sequence. This password must be used when DESL is executed.

The DESLPW environmental variable is the best place to define the DESL password. Although it is not the only way for it to be defined, this method of definition is the cleanest way to define the DESL password.

There is an additional means by which the DESL password may be set.

If a file called DESLPW exists in, first, the path defined by the DESLH Environmental variable or, second, the current directory and the content of the first line of this file is the 16-character DESL password, then the DESL password will be set.

A caveat : If a newer version of DESL is downloaded a new password will be effective and the DESLPW variable will have to be also updated.

The DESLINIT type file is the next logical location to locate the "password 16-character_string" command, although it could be entered manually at the command line prompt.

If the demonstration version of DESL is being executed then, in addition to the two items included on the "password 16-character_password" line, the current date in the form mmddyy, for a 2-digit month number, or mddyy, for a 1-digit month number, must also be included as the third item on the line.

Example :  password  4ErtF29dWlpQn28z  012399

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( TMmodes) DESL Modes of Execution

1. The purely interactive mode is the default mode if no DESL input file name follows the "desl" program name on the same line.

   Example : desl

   Here, following the carriage return after the desl invocation, DESL will solicit input from the user until the user causes the system to end.

2. The purely batch mode is entered into when a DESL input file name follows the "desl" program name on the same line.

   Example : desl DESL_input1

   The above file "DESL_input1" should end with the stopn command to force the DESL session to end gracefully.

   Here DESL will read all of its input from the named alternate file until some form of the stop command is encountered.

3. A third mode is a combination of both (1) and (2) above.

   Once DESL is begun in the purely interactive mode, one or more input files can be used to direct the DESL activity. (See the input command for more details.)

   Example :

   desl
   input dasinput1
   input dasinput2

   Here DESL will read all of its input from the two named alternate files and then return to the standard prompt to wait for more user input.

4. A variation of the purely batch mode of input occurs when all of the input is contained in a string following desl. DESL can accept an encoded up-to-128-character input sequence on the command line itself.

   Example : desl X#copy/files^run10/names^alpha^cl^cd^go/sn/

   where all of the DESL input is contained on the command line itself in an up-to 128-character string which contains no blanks. It is important to note here that whether or not an explicit "stop" or "stop" variation is specified at the end of the string it will be inferred; DESL will stop after using the commands, etc in the string.

   The syntax of such a string is the following :

   • X : the name of a scratch file where the rest of the input will be written
   • # :a separator between the file name and the rest of the string
   • / : a separator implying a new line
   • ^ :a separator implying a space

   The example above would have been equivalent to having specified the following more traditional input sequence :

   desl
    copy
     files run10
     names alpha cl cd go
    sn
   

   ---

   Regardless of the mode of the DESL invocation, except in the case of the specification of the input in a single string as described in (4) above, there are several DESL settings which can be effected on the command line - i.e., before DESL actually begins to execute.

   A command line which looks like :

   desl  (fn)  -opt1  -opt2  ...
   

   allows several options ( "opt1", "opt2", ...) to be set from the command line.

   ** Note that if an input file name ("fn") is specified if must be specified before any options are specified.

   The current allowable options and their meanings are :

   • -noecho

     Equivalent to "echo off", turning the DESL system echoing off. (See the echo command.)

   • -nolog

     Equivalent to "log off", turning the DESL system logging off. (See the log command.)

   • -asys

     Equivalent to "autosys on", turning on the DESL "system" prefixing capability. (See the system command.)

   • -V reg# val

     Equivalent to "reg set *V# val ", where "#" is a user value register number from 1 to 10 and "val" is a real or integer value to assign to the specified user value register. (See the register command.)

   • -N reg# str

     Equivalent to "reg set *N# str ", where "#" is a user name register number from 1 to 10 and "str" is an up-to 16-character string to assign to the specified user name register. (See the register command.)

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( TMfiles) Data Files

In general, the data files DESL reads and creates are in the SIF format. SIF is a particular binary, uneditable file/record structure which is convenient for the storage of serially recorded, multivariate data. Other ASCII equivalent forms of the SIF file can also be dealt with : translated to/from SIF format.

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(TMaccess) General DESL file Access/Creation

A DESL session is usually a series of individual file accesses and file creations.

Created files remain in the current directory until explicitly removed. The ramification of this operational philosophy is that even if a catastrophic event should occur during a DESL session, all files created up to that time will remain in existence.

The user must remain aware, though, that it is possible to create numerous new files during a DESL session. Many of the created files are only temporarily needed in the process of ultimately generating only a relatively few final files. Since all created files remain until removed, file populations must be closely monitored.

DESL provides a means of aiding the user in the task of dealing with a session's Data file population. (See the files and cleanup commands.)

The DESL functions which can create new SIF files also allow the user to explicitly name these new files via the newfiles or the newfilex option and argument lists. A new file which is named via newfiles is marked as a file whose fate is to be retained at the time DESL ends.

A new file which is named via newfilex is marked as a file whose fate is to be purged at cleanup. (See the cleanup command.)

Files created which have not been explicitly given a new file name will be named gen#, where "#" is a numeric suffix which makes the file name unique in the current directory. Such created files will be marked with a fate is to be purged at cleanup.

Also, if DESL's ability to overstore SIF files is off and a new file name has been specified and the new file name is the same as a file in the current directory, the new file name is changed to the gen# type name. The fate of a particular file whose name has had to be changed in this manner remains the same; i.e., remains set to that which was set according the whether newfiles or newfilex was specified.

Each DESL session will create, and report to the user that it has created, a log file. The name of this type file is log#.dsl, where "#" is a unique numeric suffix.

During a normal DESL execution several working files are temporarily created. At normal DESL termination these working files are removed.

If DESL is aborted before it can normally finish, these working files which are in existence at the current point in the session will remain in the current directory. There is no use which can be made of these leftover working files. These type files are named d*s#, where * is a two-digit number and # is a unique numeric suffix. Since these leftover files above can accumulate, their population should be monitored.

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(TMsearch) Data file searches

The hierarchy of locations from which a DESL function will attempt to access Data file(s) is the following :

1. locations which may have been specified via the paths option,
2. the current directory, if the respective paths path is blank,
3. any alternate system-wide locations established via the path command

Contact the DESL manager

ViGYAN, Inc.

30 Research Drive Hampton, VA 23666 Voice: (757) 865-1400 Toll Free: (800) 288-3998 FAX: (757) 865-8177

© 1999 ViGYAN, Inc.