open

Name

opendb, opbudb — Open database

Synopsis

#include "memcom.ins"

subroutine opdidb(handle,fname,iopen,pw,status)
integer*4 handle
character*(*) fname
integer*4 iopen
character*(*) pw
integer*4 status

subroutine opbudb(handle,fname,iopen,pw,lbuf,lpage,status)
integer*4 handle
character*(*) fname
integer*4 iopen
character*(*) pw
integer*4 lbuf
integer*4 lpage
integer*4 status

Description

opdidb and opbudb open a database for access by the current process. The file remains in the MemCom environment by the associated file number until a call to enddb or endadb is issued. Notice that file handle numbers are independent of Fortran file unit numbers. opdidb opens the file in direct mode, and opbudb opens the file in buffered mode (see introduction to the DB system).

Parameters

handle: Database handle (input). The file handle handle must be in the range of 1 to the maximum number of simultaneously open databases and it may not exceed the maximum number of simultaneously open databases.
fname: File name (input). The string may not exceed the maximum file name size.
iopen: File open code (input). iopen takes the following values defined in memcom.ins: MCORWUN opens the file for reading and writing (if the file exists it is opened, if not, a new file is created). MCORWOLD opens the file for reading and writing (if the file exists it is opened, if not, an error is reported). MCORWNEW opens a new file for reading and writing (if the file exists an error is reported). MCORWSCR opens a temporary (scratch) file for reading and writing, the file being deleted after the close operation. MCORDO opens the file for reading only (if the file does not exist an error is reported).
pw: Dummy variable (input). Must be specified as blank string of the form ' '.
lbuf: Paged input/output buffer size counted in integer*4 words (input). Buffered mode only.
lpage: Paged input/output page size counted in integer*4 words (input). See Chapter 1 for detailed explanations. Buffered mode only.
status: Status code returned (output). Upon successful completion of the operation, the status value 0 is returned. A negative value is returned, if an error has been detected. A positive value is returned, if a warning has been issued. See MemCom error codes.

Example

Open a new database on file handle (unit) 3 in unbuffered (direct) mode. The file name corresponds to UNIX syntax. Default values for the number of tables as well as the number of entries per table are assumed.

#include "memcom.ins"
        call opdidb(3,'test.mc',MCORWNEW,' ',status) 
        if(status.lt.0) stop