dlopen - open a logical RMSfile


#include <cbase/dirio.h>

DFILE *dlopen (lname, mode)

char *lname, *mode;


Dlopen opens a logical RMSfile for further I/O. If successfully opened, dlopen returns a pointer to a control block to identify the RMSfile in subsequent operations.

Lname names the RMSfile to be opened. Dlopen understands both logical names and path names. If lname is a logical name, it must be defined in the C/Base database catalog. Lname can have any of the following formats:

Format Action

dbase~lfile Open logical RMSfile

~lfile Open logical RMSfile in default database

lfile Open logical RMSfile in default database

path name Open RMSfile

Mode is a character string describing the types of operations to be done on the RMSfile. Mode may have one of the following values:

Modes Operations

r open for reading

w zero RMSfile records, open for writing

a open for writing

u open for reading and writing


dlopen(C-3), dopen(C-3), dclose(C-3), dbopen(C-3)


Dlopen returns a NULL pointer if the logical RMSfile is not defined, or if the RMSfile cannot be accessed. If NULL is returned, the RMS error message is set describing the reason for not opening the RMSfile.


If the RMSfile is opened for writing (mode is w, a, or u), the database log file is opened. If lname is a pathname of an RMSfile, transaction logging is disabled for that RMSfile.