EvmVarSet(3)EvmVarSet(3)NAME
EvmVarSet, EvmVarSetXxx, EvmVarSetStringI18N, EvmVarSetOpaque, EvmVar‐
Get, EvmVarGetType, EvmVarGetXxx, EvmVarGetString, EvmVarGetOpaque,
EvmVarRelease, EvmVarListGet, EvmVarListFree - Manipulate event vari‐
ables
SYNOPSIS
#include <evm/evm.h>
EvmStatus_t EvmVarSet(
EvmEvent_t event,
EvmVarName_t v_name,
EvmVarType_t type,
EvmVarValue_t item_value,
EvmI18NMsgId_t msg_id,
EvmSize_t size ); EvmStatus_t EvmVarSetXxx(
EvmEvent_t event,
EvmVarName_t v_name,
const evm_type item_value ); EvmStatus_t EvmVarSetStringI18N(
EvmEvent_t event,
EvmVarName_t v_name,
const EvmString_t item_value,
EvmI18NMsgId_t msg_id ); EvmStatus_t EvmVarSetOpaque(
EvmEvent_t event,
EvmVarName_t v_name,
const EvmOpaque_t item_value,
EvmSize_t size ); EvmStatus_t EvmVarGet(
EvmEvent_t event,
EvmVarName_t v_name,
EvmVarStruct_t *var ); EvmStatus_t EvmVarGetType(
EvmEvent_t event,
EvmVarName_t v_name,
EvmVarType_t *type ); EvmStatus_t EvmVarGetXxx(
EvmEvent_t event,
EvmVarName_t v_name,
evm_type *item_value ); EvmStatus_t EvmVarGetString(
EvmEvent_t event,
EvmVarName_t v_name,
EvmString_t *item_value,
EvmI18NMsgId_t *msg_id ); EvmStatus_t EvmVarGetOpaque(
EvmEvent_t event,
EvmVarName_t v_name,
EvmOpaque_t *item_value,
EvmSize_t *size ); EvmStatus_t EvmVarRelease(
EvmVarStruct_t *var ); EvmStatus_t EvmVarListGet(
EvmEvent_t event,
EvmCount_t *var_count,
EvmVarList_t *varList ); EvmStatus_t EvmVarListFree(
EvmVarList_t varlist );
OPERANDS
The event to be processed. The name of a variable in the event for
which data is to be set or obtained.
For EvmVarSet(), if the named variable exists, the associated
data is modified. If the variable does not exist, it is created
and added to the event. The value to be stored is passed in
item_value. The enumeration constant for the type of the
item_value to be stored in the variable indicated by v_name.
Possible values for this field are: EvmTYPE_BOOLEAN, Evm‐
TYPE_CHAR, EvmTYPE_INT16, EvmTYPE_INT32, EvmTYPE_INT64, Evm‐
TYPE_UINT8, EvmTYPE_UINT16, EvmTYPE_UINT32, EvmTYPE_UINT64, Evm‐
TYPE_FLOAT, EvmTYPE_DOUBLE, EvmTYPE_STRING, EvmTYPE_OPAQUE
For EvmVarGetType(), this operand is a returned value. The
value to be stored in the variable indicated by v_name. For a
string variable being set in an internationalized event, this
argument may contain an I18N message identifier corresponding to
the value of the variable. The identifier must refer to a mes‐
sage in the catalog and message set associated with the event
(see the EvmItemSet(3) reference page). This operand is ignored
for variables whose type is not EvmTYPE_STRING. The size of the
associated item_value in bytes. The caller must specify the cor‐
rect size when setting a variable of type EvmTYPE_OPAQUE. For
all other variable types, the size is ignored. For the EvmVar‐
Get() routine, this is a pointer to the location where the out‐
put data is to be stored.
For the EvmVarRelease() routine, this is a pointer to the stor‐
age space to be released. This is the number of names in the
var_list obtained by EvmVarListGet(), not including the termi‐
nating NULL pointer. On return from the EvmVarListGet() rou‐
tine, this is a list of pointers to the names of the variables
associated with the event. The last item in the list is a NULL
pointer.
For the EvmVarListFree() routine, this is a list of names of
variables for which memory should be freed. The list must be
terminated by a NULL pointer.
DESCRIPTION
The EvmVarSet() routine sets the value of a variable data item, indi‐
cated by v_name, in an event. This routine is used both for adding a
variable and for altering its value. If the v_name variable is not
already present in the event, it is added.
The EvmVarSetXxx(), EvmVarSetStringI18N()(), and EvmVarSetOpaque() rou‐
tines offer a simpler means of setting a variable than the generic Evm‐
VarSet() routine. Using these routines, you can set a variable of any
type with a single call. To use them, replace the Xxx() in the routine
name with the required type name, and supply a value of the correspond‐
ing type as the item_value operand. The following types are supported:
Boolean, Char, Int16, Int32, Int64, Uint8, Uint16, Uint32, Uint64,
Float, Double, String
Use EvmVarSetStringI18N()() to set a string variable with a non-zero
I18N message-ID, and EvmVarSetOpaque() to set an opaque variable. Each
of these routines requires one more operand than the others in this
group.
The EvmVarGet() routine returns the event variable indicated by v_name
in the var variable. The caller must free any space used by the vari‐
able by calling EvmVarRelease().
The EvmVarGetType() routine returns the type of the named variable.
The EvmVarGetXxx(), EvmVarGetString() and EvmVarGetOpaque() routines
offer a simpler means of retrieving a variable value than the generic
EvmVarGet() routine. Using these routines, you can retrieve a variable
of a specific type with a single call. To use them, replace the Xxx()
in the routine name with the required type name, and supply a pointer
to a location of the corresponding type as the item_value pointer.
Refer to the description of EvmVarSetXxx() above for details of the
supported types.
Use EvmVarGetString() to retrieve a string variable, specifying NULL
for the msg_id operand if you do not want to receive an I18N message-
ID. Use EvmVarGetOpaque() to retrieve an opaque variable. Each of these
routines requires one more operand than the others in this group.
Note that EvmVarGetString() and EvmVarGetOpaque() return their variable
values in heap memory. You must use free() to free this space when you
have finished with it.
The EvmVarRelease() routine releases any storage space that was allo‐
cated when the specified var was retrieved from an event using EvmVar‐
Get(). It is important that this routine is called when the variable is
no longer needed, to ensure that all memory associated with the vari‐
able is released. You must not use this routine to release variables
retrieved with any of the EvmVarGetXxx() routines.
The EvmVarListGet() routine returns, in the varList reference argument,
a pointer to an array of pointers to names of all the variables con‐
tained in the event. The last entry in the array is a NULL pointer.
The var_count argument receives the number of names in the list, not
counting the terminating null value. The caller must free the memory
used by the list by calling EvmVarListFree().
The EvmVarListFree() routine frees the memory used by a variable list
(varList).
NOTES
The caller must specify the size when adding an opaque variable to an
event.
RESTRICTIONS
To avoid memory leakage, memory that is supplied to the caller from API
routines must be freed with the appropriate routine.
RETURN VALUES
The operation was completed without error. One of the arguments to the
function was invalid. The type of one of the arguments to the function
was invalid. A value in a structure member was invalid. An operation
failed because an attempt to acquire heap memory failed. A request
specified an item or variable name component in an itemList or a
varList that is not part of the event being processed.
ERRORS
None
LIBRARY
EVM Support Library (libevm.so, libevm.a)
FILES
None
SEE ALSO
Files: kevm(7)
Event Management: EVM(5)
EVM Events: EvmEvent(5)
Programmer's Guide
EvmVarSet(3)
