Environment

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Environment

PQLServer

The SIR/XS PQLserver is an executable that allows another standard SIR/XS session to connect as a client and to transmit commands to the server, execute those commands remotely and retrieve output. This is done with a set of PQL functions. The PQLServer must be started to enable clients to communicate to it across the network. The client processes do not require any access to files or databases that are local to the server and the two processes (client/server) may be using different hardware/operating systems e.g. client on windows, server on Unix.

From the client point of view processing is as follows:

Client logs on to server and gets back a client id. The client id is used in all subsequent communication with the server. If the server is started with the UPASS parameter then the client must specify the server administration password to be allowed to log on.
Client sends any number of lines of text that would include SIR commands. Control usually passes back without any actual transmission taking place - transmission only happens when maximum message size is reached.
Client starts execution of previously sent commands. Any commands not yet sent to the server are transmitted, any settings or output from a previous execution from the same client are re-initialised, the commands are run and a completion code is returned at which point any output is waiting on the server. Commands can include all SIR commands and can use procedures, etc. Note that commands must include connecting any databases/tabfiles/procedure files needed each time commands are submitted and executed. There are no saved settings between executions. The process may read/write files, update databases and generally do anything that a batch run of SIR can do. While executing, no communication is happening with other possible clients. It is thus good practice to keep execution streams as short as possible.
The client may choose to wait for the execution to finish or to carry on processing locally and subsequently test to find if the execution has completed successfully.
Client gets count of number of lines of output and can then get each text line or skip over unwanted lines. Lines are physically passed by the server in groups. If skipping lines and the lines have not yet been transmitted, they are skipped on the server. Lines once returned or skipped are no longer available. The client can get a count of the number of lines available at any point.
Client can repeat the process.
Client logs off when finished.

e.g.

program
compute client = serlog (0,'TONYDELL:4000','')
write client
compute x = sersend (client,'PROGRAM')
compute x = sersend (client,'WRITE "HELLO WORLD"')
compute x = sersend (client,'END PROGRAM')
compute rc = serexec (client,1)
write 'rc = ' rc
compute olines = serlines(client)
write 'lines ' olines
for i=1,olines
. compute line = serget (client,0)
. write line
rof
compute client = serlog (client,'TONYDELL:4000','')
end program

Client Functions when using PQLServer

SERADMIN Various server administration capabilities (returning numeric values)

SERADMIS Various server administration capabilities (returning string values)

SEREXEC Instructs server to execute previously sent commands

SERGET Gets a line of output from server

SERLINES Asks server how many lines of output are left

SERLOG Logs on to the server

SERSEND Sends a string to the server

SERSENDB Sends a buffer to the server

SERTEST Asks server if execution has completed

PQLServer Functions

(These have no effect if used in a program that is not running on the server)
SERNOOUT Suppresses server output

SERWRITE Writes a line of output from server

PQLServer commands

CLEAR SERVER NOOUTPUT
SET SERVER NOOUTPUT

These can be used anywhere in the command stream to control selectively what output is made available for retrieval by the client. SET means that any output directed to standard output is thrown away. If this command is within a PQL program, it affects any compilation listing. Use the SERNOOUT(n) function for execution time control.

Running the PQLServer

The PQLserver must be running somewhere on the network to support any VisualPQL client processing. Start the PQLserver by running PQLServer.exe. This starts the server at the default port of 4000 and, in a text window, reports the current IP address. There are a small number of command line options:

PQLServer.EXE

options

PQLServer

Client Functions when using PQLServer

PQLServer Functions

PQLServer commands

Running the PQLServer

Options

Controlling server locally

Message Log