EvmSrvStart(3) Library Functions Manual EvmSrvStart(3)
NAME
EvmSrvStart(), EvmSrvMessageGet() - event service functions
SYNOPSIS
Remarks
is not currently supported for general use.
Library
EVM Support Library
Parameters
service_name The name for this service. The name must be a service defined in the EVM daemon configuration file,
.CR /etc/evmdaemon.conf .
arg_string If this operand is not NULL, it is written to the connection when the service is started.
transport Specify the type of connection to be made to the daemon. Because EVM currently supports only local connection the daemon,
transport must always be set to NULL. If this argument is not NULL, an error occurs.
EVM does not support remote connection.
connection For this is the return operand. The calling routine passes this value to when it is done with the connection.
For this is the service connection that is read for a message.
event If this operand is not NULL on return, it contains an EVM event returned by the service.
msg If this operand is not NULL on return, it contains a character string returned by the service.
errmsg If this operand is not NULL on return, it contains an error message character string returned by the service.
info If this operand is not NULL on return, it contains numeric information returned by the service.
DESCRIPTION
The routine creates a service connection to the EVM daemon, requesting that the service identified as service_name be started. If the ser-
vice is known to the daemon, it is started as a child process of the daemon, and the connection is transferred to the service process. If
the arg_string is not NULL, the function then appends a newline character to it and writes it to the connection.
The routine reads a single EVM service protocol message from the service connection identified by connection and returns it to the caller.
The message may be a procedural protocol message, indicating that the service has started or terminated, or it may carry data. Procedural
messages are handled by the API function. Data messages may be any one of the following:
o An EVM event returned to the caller in event
o A character string returned to the caller in msg
o An error character string returned to the caller in errmsg
In each of these cases, the data is returned to the caller only if the address passed to the function as the corresponding argument is not
NULL.
The function returns a non-null value in at most one of these return arguments, and sets the others to NULL. If the incoming message does
not include data (for example, if it is a protocol message indicating that the service is terminating) all three of the arguments are set
to NULL.
The message may carry one information item, which is returned if info is not NULL. This value is used in the service termination protocol
message to indicate the exit code of the service process.
Notes
is not currently supported for general use.
RETURN VALUE
If a non-null pointer was supplied as the appropriate argument, a received data message is available in one of the three data return argu-
ments.
The service indicated that it was terminating. If the caller passed a
non-null data argument, the service process's exit code is returned in the info operand.
The service connection was closed by the service before a service
termination message was received. This value is returned if the caller continues to attempt the call after the service has been ter-
minated.
ERRORS
The value of is not set.
FILES
/etc/evmdaemon.conf evmd configuration file
SEE ALSO
Commands
evmget(1).
Routines
EvmConnDestroy(3).
Files
evmdaemon.conf(4).
Event Management
EVM(5).
Event Connection
EvmConnection(5).
EVM Events
EvmEvent(5).
EvmSrvStart(3)