ZeroMQ API (8) Exceptions & Properties

1. Error handling

1.1 zmq_errno（）

1.1.1 Name

　　zmq_errno - retrieves the value of errno for the calling thread

1.1.2 Overview

　　int zmq_errno（void）;

1.1.3 Description

　　The zmq_errno() function will retrieve the value of the calling thread's errno variable.

　　The zmq_errno() function is used to help users on non-POSIX systems that have problems retrieving the correct value of errno directly. Specifically, on WinMy systems, users whose applications are using a different C runtime library from the C runtime library that ZMQ is using need to use zmq_errno() for proper operation.

　　Users who have not had problems retrieving the correct value for errno should not use this function, but should instead access the errno variable directly.

1.1.4 Return value

　　The zmq_errno() function will return the value of the calling thread's errno variable.

1.2 zmq_strerror（3）

1.2.1 Name

　　zmq_strerror - get ZMQ error message string

1.2.2 Overview

　　const char * zmq_strerror（int errnum）;

1.2.3 Description

　　The zmq_strerror() function will return a pointer to the error message string corresponding to the error number specified by the errnum parameter. Since ZMQ defines an additional number of errors beyond those defined by the operating system, applications should prefer to use zmq_strerror() over the standard strerror() function.

1.2.4 Return value

　　The zmq_strerror() function should return a pointer to the error message string.

1.2.5 Errors

　　There are no definition errors.

2. Properties

2.1 zmq_has（）

2.1.1 Name

　　zmq_has - Check ZMQ capabilities

2.1.2 Overview

　　int zmq_has（const char * capability）;

2.1.3 Description

　　The zmq_has() function should report whether the specified function is available in the library. This allows bindings and applications to probe the library directly for transport and security options.

　　function should be a lowercase string. The following functions are defined:

　　ipc - the library supports the ipc:// protocol
　　pgm - the library supports the pgm:// protocol
　　tipc - the library supports the tipc:// protocol
　　norm - the library supports the norm:// protocol
　　curve - the library supports the CURVE security mechanism
　　gssapi - the Library supports GSSAPI security mechanism

　　When this method is provided, the zmq.h header file will define ZMQ_HAS_CAPABILITIES.

2.1.4 Return value

　　The zmq_has() function shall return 1 if the specified capability is provided. Otherwise it should return 0.

2.2 zmq_version（）

2.2.1 Name

　　zmq_version - reports ZMQ library version

2.2.2 Overview

　　void zmq_version（int * major，int * minor，int * patch）;

2.2.3 Description

　　The zmq_version() function should populate the integer variables pointed to by the major, minor and patch parameters with the major, minor and patch level components of the ZMQ library version.

　　This feature is intended for applications or language bindings that dynamically link to the ZMQ library in order to determine the actual version of the ZMQ library they are using.

2.2.4 Return value

　　There is no return value.

2.2.5 Errors

　　There are no definition errors.