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macOS How to check if a port is open?
- Thread starter Xino
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You will have to try connecting to the remote address and port (I'm assuming you want to connect to a remote TCP Server).
At the lowest level BSD sockets C API, the connect() call returns a -1 on failure and sets the global errno variable to ECONNREFUSED when no one is listening on the remote address.
NSStream and CFSocket will return an error code or error object, but although these may be enough to say that the connection failed, I'm not sure they'll tell you why it failed.
The good news is you can assume that both Cocoa and Core Foundation use BSD sockets underneath the hood and so you can check the errno variable after a failed connection attempt as you would had you written this using the sockets API versus Cocoa/CoreFoundatation.
(errno should be thread-safe on OS-X)
or maybe NSError will translate errno for you:
Handling Stream Errors
try it and find out
At the lowest level BSD sockets C API, the connect() call returns a -1 on failure and sets the global errno variable to ECONNREFUSED when no one is listening on the remote address.
NSStream and CFSocket will return an error code or error object, but although these may be enough to say that the connection failed, I'm not sure they'll tell you why it failed.
The good news is you can assume that both Cocoa and Core Foundation use BSD sockets underneath the hood and so you can check the errno variable after a failed connection attempt as you would had you written this using the sockets API versus Cocoa/CoreFoundatation.
(errno should be thread-safe on OS-X)
or maybe NSError will translate errno for you:
Handling Stream Errors
try it and find out