mcDBinqSetAtt

Name

mcDBinqSetAtt — inquire dataset attributes

Synopsis

#include <memcom.h>

int mcDBinqSetAtt(int handle, const char* name, 
                  mcSetAttributes* att);

Description

mcDBinqSetAtt returns the attributes of a dataset in a structure of type mcSetAttributes. The database pointed to by handle is searched. If the set exists, the function returns 1. If not, 0 is returned. If the handle has a wrong value or the database assigned to handle is not open, the function returns a negative value.

If the structure att is set to NULL before calling mcDBinqSetAtt no values are returned, i.e the function can be used to check if the set exists, without retrieving any attributes.

Parameters

handle

Database handle (input).

name

Dataset name of set to be inquired (input).

att

Pointer to structure of type mcSetAttributes (input). If set to NULL, no values are returned, i.e the function can be used to check if the set exists. mcSetAttributes structure:

#include <memcom.h>

struct mcSetAttributes {
    char    name[SET_NAME_LENGTH + 1]; /* Name ('\0'-terminated) */
    char    type[4];    /* Data set type ('\0'-terminated). */
    int     ndim;       /* Number of array dimensions (1,2,3...) */
    mcOff   dim[5];     /* ndim Dimensions */
    mcOff   size;       /* Total size in number of elements */
    mcOff   faddr;      /* File address (bytes) */
    mcSize  dsize;      /* Descriptor size (bytes). 0 means no descriptor. */
};

Additional Notes

SET_NAME_LENGTH is the maximum size of a dataset name (usually 64 characters). It can be retrieved from mcdefs.h.

All size information is expressed in data elements.

Only the first ndim elements of dim are defined. ndim = 0 means that the size is not (or not yet) defined. The dimensions of dim correspond to the C array row-major order.

A C array a[100][3] must be dimensioned with

mcSetAttributes att;
att.ndim=2;
att.dim[0]=100;
att.dim[1]=3;