nn_symbol(3)

1NN_SYMBOL(3)                     nanomsg 1.1.5                    NN_SYMBOL(3)
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NAME

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

9       #include <nanomsg/nn.h>
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11       const char *nn_symbol (int i, int *value);
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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.
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18       Typically a client will iterate through the symbols until nn_symbol
19       returns NULL in order to collect all the symbols.
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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.
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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).
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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.
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37       If i is out-of-range, nn_symbol returns NULL and sets errno to EINVAL.
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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.
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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           }
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AUTHORS

56       Evan Wies <evan@neomantra.net>
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60                                  2021-01-26                      NN_SYMBOL(3)