EvmVarSet(3) Library Functions Manual EvmVarSet(3)
NAME
EvmVarSet, EvmVarSetXxx, EvmVarSetStringI18N, EvmVarSetOpaque, EvmVarGet, EvmVarGetType, EvmVarGetXxx, EvmVarGetString, EvmVarGetOpaque,
EvmVarRelease, EvmVarListGet, EvmVarListFree - Manipulate event variables
LIBRARY
EVM Support Library (libevm.so, libevm.a)
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, EvmTYPE_CHAR, EvmTYPE_INT16, EvmTYPE_INT32, EvmTYPE_INT64, EvmTYPE_UINT8, EvmTYPE_UINT16, EvmTYPE_UINT32, Evm-
TYPE_UINT64, EvmTYPE_FLOAT, EvmTYPE_DOUBLE, EvmTYPE_STRING, EvmTYPE_OPAQUE
For EvmVarGetType(), this parameter 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 message in the catalog and message set associated with the event (see the EvmItem-
Set(3) reference page). This parameter is ignored for variables whose type is not EvmTYPE_STRING. The size of the associated
item_value in bytes. The caller must specify the correct size when setting a variable of type EvmTYPE_OPAQUE. For all other vari-
able types, the size is ignored. For the EvmVarGet() routine, this is a pointer to the location where the output data is to be
stored.
For the EvmVarRelease() routine, this is a pointer to the storage space to be released. This is the number of names in the var_list
obtained by EvmVarListGet(), not including the terminating NULL pointer. On return from the EvmVarListGet() routine, 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 termi-
nated by a NULL pointer.
DESCRIPTION
The EvmVarSet() routine sets the value of a variable data item, indicated 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() routines 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 rou-
tine name with the required type name, and supply a value of the corresponding type as the item_value parameter. 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 parameter 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
variable 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 parameter if you do not want to receive an I18N mes-
sage-ID. Use EvmVarGetOpaque() to retrieve an opaque variable. Each of these routines requires one more parameter than the others in this
group.
Note that EvmVarGetStringI18N(), EvmVarGetStringI18N() and EvmVarGetOpaque() all 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 allocated 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
variable 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
contained 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. A value in a structure member is invalid.
An operation failed because an attempt to acquire heap memory failed. A request specified an item or variable name component in an item-
List or a varList that is not part of the event being processed.
ERRORS
None
FILES
None
SEE ALSO
Event Management: EVM(5)
EVM Events: EvmEvent(5)
Common Desktop Environment: Programmer's Guide delim off
EvmVarSet(3)