1NN_SYMBOL(3) nanomsg 1.1.5 NN_SYMBOL(3)
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6 nn_symbol - query the names and values of nanomsg symbols
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9 #include <nanomsg/nn.h>
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11 const char *nn_symbol (int i, int *value);
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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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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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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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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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53 nn_symbol_info(3) nn_errno(3) nn_strerror(3) nanomsg(7)
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56 Evan Wies <evan@neomantra.net>
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60 2018-10-15 NN_SYMBOL(3)