nng_ctx_id - return numeric context identifier

       The nng_ctx_id() function returns a positive identifier for the context c, if it is valid. Otherwise it
       returns -1.

           Note

           A context is considered valid if it was ever opened with nng_ctx_open() function. Contexts that are
           allocated on the stack or statically should be initialized with the macro NNG_CTX_INITIALIZER to
           ensure that they cannot be confused with a valid context before they are opened.

       None.

       nng_ctx_id - return numeric context identifier

       This function returns the positive value for the context identifier, or -1 if the context is invalid.

nng_ctx(5), nng(7)

                                                   2025-04-20                                      NNG_CTX_ID(3)

           #include <nng/nng.h>

           int nng_ctx_id(nng_ctx c);