EvmSrvStart(3)EvmSrvStart(3)NAMEEvmSrvStart(), 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 connec‐
tion 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 service
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 ser‐
vice 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:
· An EVM event returned to the caller in event
· A character string returned to the caller in msg
· 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
arguments.
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
terminated.
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)