CInfoPBRec

#include <Files.h>

typedef union CInfoPBRec { Size Description

HFileInfo hFileInfo; 108 Use for files

DirInfo dirInfo; 104 Use for directories

} CInfoPBRec; 108 (size of aggregate)

typedef CInfoPBRec *CInfoPBPtr;

Notes: This union (or either of the HFileInfo or DirInfo structures) is used in

calls to PBGetCatInfo and PBSetCatInfo. Note that the return value of

the ioFlAttrib field (of either member structure) identifies which type of

information is returned (see PBGetCatInfo for details).

A handy technique is to allocate the CInfoPBRec union and create pointers

which refer to each data type:

CInfoPBRec cipb; /* allocate a union */

HFileInfo *hfipb=(HFileInfo *)&cipb; /* and separate struc ptrs */

DirInfo *dipb=(DirInfo *)&cipb; /* pointing same address */

cipb. hFileInfo.vRefNum = 2; /* as a union member field */

cipb. dirInfo.ioDrFndrInfo.frLocation.h = 100;

hfipb->vRefNum = 2 ; Û/* or as a structure field */

dipb->ioDrFndrInfo.frLocation.h = 100;

You can also perform ad hoc type coercion:

unsigned char pb[108]; /* big enough to hold either struct */

short theVRef;

theVRef = ((HFileInfo *)pb)-> ioVRefNum; /* fetch 1 field */

((HFileParam *)pb)->ioFlLgLen = 1000L; /* change some fields */

((HFileInfo *)pb)->ioFlClpSiz = 2048;

GetDateTime(&((HFileInfo *)pb)->ioFlMdDat);

/* access chars of a long */

printf("File type is '%c%c%c%c'\n", pb[32], pb[33], pb[34],pb[35]);

Referenced by (26):