NAME¶
snmp_pdu_add_variable, snmp_varlist_add_variable, snmp_add_null_var,
snmp_clone_varbind, snmp_set_var_objid, snmp_set_var_value,
snmp_set_var_typed_value, snmp_set_var_typed_integer, print_variable,
fprint_variable, snprint_variable, print_value, fprint_value, snprint_value,
snmp_free_var, snmp_free_varbind - netsnmp_varbind_api functions
SYNOPSIS¶
#include <net-snmp/varbind_api.h>
Creation¶
netsnmp_variable_list *snmp_pdu_add_variable(
netsnmp_pdu *pdu,
const oid *objid, size_t objidlen,
u_char type, const void *value, size_t
len);
netsnmp_variable_list *snmp_varlist_add_variable(
netsnmp_variable_list *varlist,
const oid *objid, size_t objidlen,
u_char type, const void *value, size_t
len);
netsnmp_variable_list *snmp_add_null_var(
netsnmp_pdu *pdu,
const oid *objid, size_t objidlen);
netsnmp_variable_list *snmp_clone_varbind(
netsnmp_variable_list *varlist);
Setting Values¶
int snmp_set_var_objid( netsnmp_variable_list* variable,
const oid * objid, size_t objidlen);
int snmp_set_var_value( netsnmp_variable_list* variable,
const void * value, size_t vallen);
int snmp_set_var_typed_value( netsnmp_variable_list*
variable,
u_char type,
const void * value, size_t vallen);
int snmp_set_var_typed_integer( netsnmp_variable_list*
variable,
u_char type, long value);
Output¶
void print_variable(const oid *objid, size_t
objidlen,
const netsnmp_variable_list *variable);
void fprint_variable(FILE *fp,
const oid *objid, size_t objidlen,
const netsnmp_variable_list *variable);
int snprint_variable(char *buf, size_t len,
const oid *objid, size_t objidlen,
const netsnmp_variable_list *variable);
void print_value(const oid *objid, size_t
objidlen,
const netsnmp_variable_list *variable);
void fprint_value(FILE *fp,
const oid *objid, size_t objidlen,
const netsnmp_variable_list *variable);
int snprint_value(char *buf, size_t len,
const oid *objid, size_t objidlen,
const netsnmp_variable_list *variable);
Deletion¶
void snmp_free_var( netsnmp_variable_list *variable);
void snmp_free_varbind( netsnmp_variable_list *variables);
DESCRIPTION¶
The functions dealing with variable bindings fall into four groups - dealing
with the creation, setting of values, output and deletion of varbinds.
Creation¶
snmp_pdu_add_variable will create a new varbind structure, initialised
with the name (
objid,
objidlen ), syntax (
type ) and
value (
value , len ) provided. This varbind is then added to the end
of the varbind list in the given PDU.
snmp_varlist_add_variable is similar, but appends the new varbind to the
end of the varbind list provided. When adding the first varbind to an empty
list, simply pass the address of the head of the list:
-
netsnmp_variable_list *vl = NULL;
snmp_varlist_add_variable(
&vl, name1, name1_len,
ASN_ TYPE, &val1, val1_len);
snmp_varlist_add_variable(
&vl, name2, name2_len,
ASN_ TYPE, &val2, val2_len);
In both cases, the routine will return a pointer to the new varbind structure
(or NULL if the varbind creation fails).
snmp_add_null_var is a convenience function to add an empty varbind to
the PDU. without needing to specify the NULL value explicitly. This is the
normal mechanism for constructing a GET (or similar) information retrieval
request.
Again, this returns a pointer to the new varbind, or NULL.
snmp_clone_varbind creates a copy of each varbind in the specified list,
returning a pointer to the head of the new list (or NULL if the cloning
fails).
Setting of values¶
snmp_set_var_objid sets the name of the varbind structure to the
specified OID.
snmp_set_var_typed_value sets the syntax type and value of the varbind
structure.
snmp_set_var_value sets the value of the varbind structure, leaving the
syntax type unchanged.
snmp_set_var_typed_integer is a convenience function to set the syntax
type and value for a 32-bit integer-based varbind.
All four of these return 0 if the assignment is successful, or 1 if it is not.
Output¶
print_variable will take an object identifier (as returned by
read_objid,
snmp_parse_oid or
get_module_node) and an
instance of such a variable, and prints to the standard output the textual
form of the object identifier together with the value of the variable.
fprint_variable does the same, but prints to the FILE pointer specified
by the initial parameter.
snprint_variable prints the same information into the buffer pointed to
by
buf which is of length
len. It returns the number of
characters printed, or -1 if the buffer was not large enough. In the latter
case,
buf will typically contained a truncated version of the
information (but this behaviour is not guaranteed). This function replaces the
obsolete function
sprint_variable.
print_value,
fprint_value, and
snprint_value do the same as
the equivalent
print_variable routines, but only displaying the value
of the variable, without the corresponding object identifier.
For displaying the OID of a varbind, see
min_api(3).
Deletion¶
snmp_free_var releases all memory used by the given varbind structure.
snmp_free_varbind releases all memory used by each varbind structure in
the varbind list provided.
SEE ALSO¶
pdu_api(3)
mib_api(3)
