nn_symbol(3)

1NN_SYMBOL(3)                     nanomsg 1.1.5                    NN_SYMBOL(3)
2
3
4

NAME

6       nn_symbol - query the names and values of nanomsg symbols
7

SYNOPSIS

9       #include <nanomsg/nn.h>
10
11       const char *nn_symbol (int i, int *value);
12

DESCRIPTION

14       Retrieves the symbol name and value at index i. Indices start at 0. An
15       index has no significance to its associated symbol; the mappings may
16       change between library versions.
17
18       Typically a client will iterate through the symbols until nn_symbol
19       returns NULL in order to collect all the symbols.
20
21       All symbols exposed by nn_symbol are available directly in the C API,
22       generally as preprocessor macros. Thus, this function is useful mostly
23       for language bindings that can’t parse the header file and rely on
24       retrieving the symbols in the runtime.
25
26       Note that the NN_MSG symbol is not exported by the nn_symbol function.
27       First, it is a pointer rather than an integer; second, the symbol is
28       not supposed to be exported from language bindings to the user.
29       Instead, language bindings should provide the zero-copy functionality
30       in a language-specific way, if at all (zero-copy functionality may not
31       make sense for some languages/bindings).
32

RETURN VALUE

34       If i is valid, returns the name of the symbol at that index. If the
35       pointer value is not NULL, the symbol’s value is stored there.
36
37       If i is out-of-range, nn_symbol returns NULL and sets errno to EINVAL.
38

ERRORS

40       EINVAL
41           The passed index i was out-of-range; it was less than zero or
42           greater-than-or- equal-to the number of symbols.
43

EXAMPLE

45           int value, i;
46           for (i = 0; ; ++i) {
47               const char* name = nn_symbol (i, &value);
48               if (name == NULL) break;
49               printf ("'%s' = %d\n", name, value);
50           }
51

AUTHORS

56       Evan Wies <evan@neomantra.net>
57
58
59
60                                  2020-01-29                      NN_SYMBOL(3)