Open a name to connect to a server
Synopsis:
#include <sys/iofunc.h>
#include <sys/dispatch.h>
int name_open( const char * name,
int flags );
Arguments:
- name
- The name that you want to open to connect to a server.
- flags
- Flags that affect the function's behavior; zero or more of the following:
- NAME_FLAG_ATTACH_GLOBAL — search for the name globally instead of locally.
- _NAME_FLAG_COF_CLOEXEC (QNX Neutrino 7.0.4 or later) — corresponds to
_NTO_COF_CLOEXEC
- _NAME_FLAG_COF_INSECURE (QNX Neutrino 7.0.4 or later) — corresponds to
_NTO_COF_INSECURE
- _NAME_FLAG_COF_NOEVENT (QNX Neutrino 7.0.4 or later) — corresponds to
_NTO_COF_NOEVENT
- _NAME_FLAG_COF_REG_EVENTS (QNX Neutrino 7.0.4 or later) — corresponds to
_NTO_COF_REG_EVENTS
For more information about the _NTO_COF_* flags, see
ConnectAttach().
Library:
libc
Use the -l c option to
qcc
to link against this library.
This library is usually included automatically.
Description:
The name_open() function opens name to connect to the server that registered that name.
No ordering is guaranteed when accessing resources on other nodes.
There's also no guarantee that the client will end up talking to the server it thinks it's connecting to;
another server process could run before the server the client is expecting to talk to
and use the name in name.
If this is a concern, your server should call resmgr_attach()
instead of name_attach() and possibly configure a
security policy.
You can make the connection more secure by setting the _NAME_FLAG_COF_INSECURE and _NAME_FLAG_COF_NOEVENT
flags. For more information, see the descriptions of the corresponding
ConnectAttach() flags.
Note:
The server application must be able handle an
_IO_CONNECT message with a subtype of
_IO_CONNECT_OPEN.
If the global name service,
gns,
is running on your system, this message is sent to the server when a client calls
name_open().
For an example, see the documentation for
name_attach().
Returns:
A nonnegative integer representing a side-channel connection ID or coid (see
ConnectAttach()),
or -1 if an error occurred
(errno is set).
Errors:
- EACCES
- Search permission is denied on a component of the name.
- EBADFSYS
- While attempting to open the named file, either the file itself or a
component of the path prefix was found to be corrupted.
A system failure—from which no automatic recovery is possible—occurred while
the file was being written to, or while the directory was being updated.
You'll need to invoke appropriate systems-administration procedures to correct this situation before proceeding.
- EBUSY
- The connection specified by name has already been opened,
and additional connections aren't permitted.
- EINTR
- The name_open() operation was interrupted by a signal.
- EISDIR
- The named path is a directory.
- ELOOP
- Too many levels of symbolic links or prefixes.
- EMFILE
- All file descriptors available to the process are currently open.
- ENAMETOOLONG
- The length of the name string exceeds
PATH_MAX, or a pathname component is longer than
NAME_MAX.
- ENFILE
- Too many files are currently open in the system.
- ENOENT
- The connection specified by name doesn't exist.
- ENOTDIR
- A component of the name prefix isn't a directory.
Classification:
QNX Neutrino
| Safety: |
|
|---|
| Cancellation point |
Yes |
| Interrupt handler |
No |
| Signal handler |
Yes |
| Thread |
Yes |