Opening a database

Now we can check that a database exists via the HEPDB interactive interface. (Later we show how to open a database via a HEPDB-calling FORTRAN program).

The following section gives a little detail upon the invocation of the interactive interface.

Invoking the HEPDB interactive interface

The interactive interface is invoked by typing hepdb. Note that the variable CDSERV must be set, specifying the directory where the appropriate HEPDB configuration file is stored.

When you log on to the system you may notice messages saying that macros xxxSYS, xxxGRP, xxxUSR, and xxxLOGON are not present. This is a normal response and refers to a HEPDB facility which allows you to execute a standard set of macros on entry to the interactive interface. The following section explains how the use of these macros is envisaged.

Using start up macros

The use of a subroutine KULOGN is as follows: 

                 Description of subroutine KULOGN
                                  

      SUBROUTINE KULOGN (CHPACK,CHOPT)
*
*    Execute logon kumacs for package `CHPACK' with options `CHOPT'
*    KUMACs are xxxSYS, xxxGRP, xxxUSR and xxxLOGON
*

Depending on the platform you are running different ways of tailoring where the macros reside are available. The search methods used by the various platforms are as follows:

  1. VAX/VMS Look in directories defined in searchlist xxxPATH ,if xxxPATH not defined, use SYS$LOGIN, SYS$DISK:[] (i.e. current and home directories).
  2. Unix Look in path xxx PATH (If not defined, use current and home directories).
  3. VM/CMS Check disks in xxxPATH. If this is not defined default to using the A disk.

    The standard set of macros currently supported by HEPDB are intended for the following use:

    1. xxxSYS This macro may contain a call to a monitoring program
    2. xxxGRP This macro would contain commands specific to a particular group.
    3. xxxUSR and xxxLOGON These two macros are intended to hold user specific information. As the default search order is the current and then home directory, one may use one macro, e.g. HDBUSR for general commands, e.g. creation of standard aliases etc. and the other, e.g. HDBLOGON for directory specific commands.

      Opening a database interactively

      HEPDB allows a database file to be opened via the OPEN command. The OPEN command must be given with the two character prefix of the database followed (optionally) by the databases' physical file name. The example below shows how to open a file interactively and the terminal output you can expect. 

                       Opening a database interactively
                                  

      HEPDB> open ge geo.dbs
       ---------------
HEPDB  1.02/14 921029 16:46 CERN PROGRAM LIBRARY HEPDB=Q180
 This version created on 921029 at 1756
CDOPNC. opened file GEO.DBS on unit  2 with top directory CDGE and record length 1024
HEPDB>

      To demonstrate that the file has now been opened you can issue another HEPDB interactive command FILES, which shows a list of all files currently open to HEPDB. 

                      Checking a file is open with FILES.
                                  

      HEPDB>files
      -----
 File #   1, unit:  2, top directory:             CDGE
 CDFILC.           1  file(s) are attached
HEPDB>
      Finally the database should now be closed. This can be done in two ways, explicitly via the CLOSE command if you wish to do more work with HEPDB during the current session or implicitly via the QUIT command if you wish to terminate the current HEPDB session. An example of the first of these cases follows: 

                      Closing a HEPDB file interactively
                                  

      HEPDB>close ge
      --------
CDCLSH. closing GEO on unit         2
CDCLSH. closed            1  file(s)
HEPDB>

      Opening a database from FORTRAN

      Below is an example section of FORTRAN code showing how HEPDB's user callable routines can be used to open a database file. Notice how the two character id code of the database is used in the call to CDPREF to obtain the full file name and top directory name of the required database. This information is then used by the call to CDOPEN which then opens the file. Finally note the use of CDEND this is the method of closing the database file. (The character option `A' signifies that all files should be closed.) 

                        Opening a database from FORTRAN
                                  

            PROGRAM EGOPEN
*     ==============
*
*     Modify an existing database
*
      PARAMETER    (NWPAW=100000)
      COMMON/PAWC/ PAW(NWPAW)
      PARAMETER    (NKEYS=10)
      PARAMETER    (MAXOBJ=1000)
      CHARACTER*8  CHTAG(NKEYS)
      CHARACTER*10 CHFOR
      CHARACTER*4  CHTOP
      CHARACTER*80 CHFILE
*
*     Initialise Zebra, HBOOK and HEPDB
*
      CALL CDPAW(NWPAW,NHBOOK,IDIV,'USR-DIV',5000,50000,'ZPHU',IRC)
*
*     Unit for database access
*
      LUNCD  = 1
*
*     Unit for database update (via journal files)
*
      LUNFZ  = 2
*
*     Find the database file and construct the top directory name
*     Pass in 'GE' (two-char id code for database) as 2nd parameter
*
      CALL CDPREF(10,'GE',CHTOP,CHFILE,IRC)
      IF(IRC.GT.4) THEN
         PRINT *,'EGOPEN. STOPPING DUE TO FATAL ERROR FROM CDPREF'
         STOP 16
      ENDIF
*
*     Open the database file
*
      LRECL  = 0
      CALL CDOPEN(LUNCD,LUNFZ,CHTOP,CHFILE,LRECL,IDIV,' ',IRC)
*
*     Do Nothing and Terminate
*
      CALL CDEND(' ','A',IRC)
      END