1VARBIND_API(3) Net-SNMP VARBIND_API(3)
2
6 snmp_pdu_add_var, snmp_varlist_add_var, snmp_add_null_var,
7 snmp_clone_varbind, snmp_free_varbind, snmp_free_var, print_variable,
8 fprint_variable, snprint_variable, print_value, fprint_value,
9 snprint_value - varbind_api functions
10
12 #include <net-snmp/varbind_api.h>
13 Creation
15 netsnmp_variable_list *snmp_pdu_add_variable(
16 netsnmp_pdu *pdu,
17 const oid *objid, size_t objidlen,
18 u_char type, const void *value, size_t len);
19 netsnmp_variable_list *snmp_varlist_add_variable(
20 netsnmp_variable_list *varlist,
21 const oid *objid, size_t objidlen,
22 u_char type, const void *value, size_t len);
23 netsnmp_variable_list *snmp_add_null_var(
24 netsnmp_pdu *pdu,
25 const oid *objid, size_t objidlen);
26 netsnmp_variable_list *snmp_clone_varbind(
28 netsnmp_variable_list *varlist);
29 Setting Values
31 int snmp_set_var_objid( netsnmp_variable_list* variable,
32 const oid * objid, size_t objidlen);
33 int snmp_set_var_value( netsnmp_variable_list* variable,
34 const void * value, size_t vallen);
35 int snmp_set_var_typed_value( netsnmp_variable_list* variable,
36 u_char type,
37 const void * value, size_t vallen);
38 int snmp_set_var_typed_integer( netsnmp_variable_list* variable,
39 u_char type, long value);
40 Output
42 void print_variable(const oid *objid, size_t objidlen,
43 const netsnmp_variable_list *variable);
44 void fprint_variable(FILE *fp,
45 const oid *objid, size_t objidlen,
46 const netsnmp_variable_list *variable);
47 int snprint_variable(char *buf, size_t len,
48 const oid *objid, size_t objidlen,
49 const netsnmp_variable_list *variable);
50 void print_value(const oid *objid, size_t objidlen,
52 const netsnmp_variable_list *variable);
53 void fprint_value(FILE *fp,
54 const oid *objid, size_t objidlen,
55 const netsnmp_variable_list *variable);
56 int snprint_value(char *buf, size_t len,
57 const oid *objid, size_t objidlen,
58 const netsnmp_variable_list *variable);
59 Deletion
61 void snmp_free_var( netsnmp_variable_list *variable);
62 void snmp_free_varbind( netsnmp_variable_list *variables);
63
65 The functions dealing with variable bindings fall into four groups -
66 dealing with the creation, setting of values, output and deletion of
67 varbinds.
68 Creation
70 snmp_pdu_add_variable will create a new varbind structure, initialised
71 with the name ( objid, objidlen ), syntax ( type ) and value ( value ,
72 len ) provided. This varbind is then added to the end of the varbind
73 list in the given PDU.
74 snmp_varlist_add_variable is similar, but appends the new varbind to
76 the end of the varbind list provided. When adding the first varbind to
77 an empty list, simply pass the address of the head of the list:
78 "[Insert example code here]"
80 In both cases, the routine will return a pointer to the new varbind
82 structure (or NULL if the varbind creation fails).
83 snmp_add_null_var is a convenience function to add an empty varbind to
85 the PDU. without needing to specify the NULL value explicitly. This
86 is the normal mechanism for constructing a GET (or similar) information
87 retrieval request.
88 Again, this returns a pointer to the new varbind, or NULL.
89 snmp_clone_varbind creates a copy of each varbind in the specified
91 list, returning a pointer to the head of the new list (or NULL if the
92 cloning fails).
93 Setting of values
95 snmp_set_var_objid sets the name of the varbind structure to the speci‐
96 fied OID.
97 snmp_set_var_typed_value sets the syntax type and value of the varbind
98 structure.
99 snmp_set_var_value sets the value of the varbind structure, leaving the
100 syntax type unchanged.
101 snmp_set_var_typed_integer is a convenience function to set the syntax
102 type and value for a 32-bit integer-based varbind.
103 All four of these return 0 if the assignment is successful, or 1 if it
105 is not.
106 Output
108 print_variable will take an object identifier (as returned by
109 read_objid, snmp_parse_oid or get_module_node) and an instance of such
110 a variable, and prints to the standard output the textual form of the
111 object identifier together with the value of the variable.
112 fprint_variable does the same, but prints to the FILE pointer specified
114 by the initial parameter.
115 snprint_variable prints the same information into the buffer pointed to
117 by buf which is of length len. It returns the number of characters
118 printed, or -1 if the buffer was not large enough. In the latter case,
119 buf will typically contained a truncated version of the information
120 (but this behaviour is not guaranteed). This function replaces the
121 obsolete function sprint_variable.
122 print_value, fprint_value, and snprint_value do the same as the equiva‐
124 lent print_variable routines, but only displaying the value of the
125 variable, without the corresponding object identifier.
126 Deletion
128 snmp_free_var releases all memory used by the given varbind structure.
129 snmp_free_varbind releases all memory used by each varbind structure in
130 the varbind list provided.
131
133 pdu_api(3) mib_api(3)
1344.2 Berkeley Distribution 20 Apr 2009 VARBIND_API(3)