| Updated: April 19, 2023 |
Link two directory entries
#include <sys/iofunc.h>
int iofunc_link( resmgr_context_t* ctp,
io_link_t* msg,
iofunc_attr_t* attr,
iofunc_attr_t* dattr,
struct _client_info* info );
libc
Use the -l c option to qcc to link against this library. This library is usually included automatically.
The iofunc_link() helper function creates a link from a new object in dattr to the existing object attr. A resource manager uses this routine when creating a new filename inside dattr which will be hard linked to attr. The iofunc_link() function checks to see if the client (described by the optional info structure) has permission to create a new name entry inside dattr. The attr structure describes the resource's attributes, and the dattr structure defines the attributes of the parent directory.
You can pass the info argument as NULL, in which case iofunc_link() obtains the client information itself via a call to iofunc_client_info_ext(). It is, of course, more efficient to get the client info once, rather than calling this function with NULL every time.
io_link_t structure
The io_link_t structure holds the _IO_CONNECT message received by the resource manager:
typedef union {
struct _io_connect connect;
struct _io_connect_link_reply link_reply;
struct _io_connect_ftype_reply ftype_reply;
} io_link_t;
This message structure is a union of an input message (coming to the resource manager), _io_connect, and two possible output or reply messages (going back to the client):
Or:
| Safety: | |
|---|---|
| Cancellation point | No |
| Interrupt handler | No |
| Signal handler | Yes |
| Thread | Yes |