Tmax provides functions for the communication network and buffer management, which enable easy development of application programs. These functions are offered as a library and compiled together with application programs. Developers can develop client programs without knowing the origin of services and servers.

Once a client program is coded, an executable file is created after a successful compilation. In order to compile a client program, the following are required: a client program written by developers, the Tmax client library, a struct file (if a struct buffer is used), and a field table definition file (if a field key buffer is used).

A client program consists of the following components:

Tmax client programs can be developed in the following environments using the listed tools:

A client program passes a request from a user to a server, and returns the results from the server to the user.

The following are the steps for writing a client program:

main()
{
        Allocate a buffer for tpstart.
        Initialize a buffer for tpstart.

        Connect to Tmax.
        Allocate a buffer for data transmission and reception
        while {
            Input user requests into the transmit message buffer.
            Send the transmit message buffer to a server (service request).
            Receive a response from the server with the receive message buffer.
            Show the receive message buffer to users.
        }
        Deallocate the transmit/receive message buffer.

        Disconnect from Tmax.
}

The following is the flow of a client program:

[Figure 2.1] Client Program Flow

The following is the process of each function in a client program:

[Figure 2.2] Process of Functions in a Client Program

The following describes the major functions of a client program.

Compile a client program to create an object file.

The following shows the process of compiling a client program using a struct buffer or fielded buffer.

[Figure 2.3] Compiling a Client Program Using a Struct Buffer

[Figure 2.4] Compiling a Client Program Using a Fielded Buffer

The following are the steps for compiling a client program.

The following is an example of a Makefile for a Tmax client program:

TARGET = <clientname> 
APOBJS = $(TARGET).o

TMAXLIBD = $(TMAXDIR)/lib

#TMAXLIBS is different according to OS.
#Solaris : TMAXLIBS = -lsocket -lnsl –lcli 
#Compac, HP, IBM, Linux : TMAXLIBS= -lcli

TMAXLIBS = -lcli 

#CFLAGS is different according to OS.
#Solaris 32bit, Compaq, Linux: CFLAGS = -O –I$(TMAXDIR)
#Solaris 64bit: CFLAGS = -xarch=v9 -O –I$(TMAXDIR)
#HP 32bit: CFLAGS = -Ae -O –I$(TMAXDIR)
#HP 64bit: CFLAGS = -Ae +DA2.0W +DD64 +DS2.0 -O –I$(TMAXDIR)
#IBM 32bit: CFLAGS = -q32 –brtl -O –I$(TMAXDIR
#IBM 64bit: CFLAGS = -q64 –brtl -O –I$(TMAXDIR

CFLAGS = -O –I$(TMAXDIR)

#
.SUFFIXES : .c

.c.o:
        $(CC) $(CFLAGS) -c $<

#
# client compile
#

$(TARGET): $(APOBJS)
         $(CC) $(CFLAGS) -L$(TMAXLIBD) -o $(TARGET) $(APOBJS) $(TMAXLIBS) 

#
clean:
        -rm -f *.o core $(TARGET)

The sample program provided by Tmax executes "make" using the shell script named "compile". To use the shell script, type the following into a command prompt. In "compile", enter the client program name without the extension into EXE of the Makefile.

compile c cli (=>client program name without its extension)

Set environment variables to start Tmax.

Since a client program gets necessary information from environment variables when connecting to Tmax, TMAX_HOST_ADDR and TMAX_HOST_PORT must be defined in the UNIX shell configuration file (c shell: .cshrc, korn shell: .profile, bash shell: .bash_profile, etc.). TMAX_BACKUP_ADDR and TMAX_BACKUP_PORT can also be defined to handle possible failures, and TMAX_CONNECT_TIMEOUT can be defined to handle possible network failures.

Client processes can be created after Tmax environment variables are set in the UNIX configuration file. The client processes are started and terminated in the method used to start and terminate other executable files.

The following describes each environment variable.

$ sdlc -c -i Struct file name [ -o sdl File name] [ -h Header file name]

$ fdlc -c -i Field buffer file name [ -o fdl File name] [ -h Header file name]