IBM Books

Building Applications for UNIX** Environments


HP-UX C/C++

The script files in this section are coded for C programs using the C compiler. To use C++ programs you need to use the C++ compiler. To do this, make the changes to the script files given in comments at the end of the files.

The script file bldcc, in sqllib/samples/c, contains the commands to build a sample C program.

The first parameter, $1, specifies the name of your source file. The second parameter, $2, specifies the name of the database to which you want to connect. The third parameter, $3, specifies the user ID for the database, and $4 specifies the password. Only the first parameter, the source file name, is required. Database name, user ID, and password are optional. If no database name is supplied, the program uses the default sample database.



#! /bin/ksh
# bldcc script file
# Builds a sample C program containing embedded SQL
# Usage: bldcc <prog_name> [ <db_name> [ <userid> <password> ]]
 
# Connect to a database.
if (($# < 2))
then
   db2 connect to sample
elif (($# < 3))
then
   db2 connect to $2
else
   db2 connect to $2 user $3 using $4
fi
 
# Precompile the program.
db2 prep $1.sqc bindfile
 
# Bind the program to the database.
db2 bind $1.bnd
 
# Disconnect from the database.
db2 connect reset
 
# Compile the util.c error-checking utility.
cc -Aa +e -I/opt/IBMdb2/v5.0/include -c util.c
 
# Compile the program.
cc -Aa +e -I/opt/IBMdb2/v5.0/include -c $1.c
 
# Link the program.
cc -o $1 $1.o util.o -L/opt/IBMdb2/v5.0/lib -ldb2 -lhppa
 
# Note: To use the C++ compiler, substitute the following steps.
# Precompile the program.
# db2 prep $1.sqC bindfile
# Compile the util.c error-checking utility.
# CC +a1 -I/opt/IBMdb2/v5.0/include -c util.c
# Compile the program.
# CC +a1 -I/opt/IBMdb2/v5.0/include -c $1.C
# Link the program.
# CC -o $1 $1.o util.o -L/opt/IBMdb2/v5.0/lib -ldb2 -lhppa


Compile and Link Options for bldcc

The script file contains the following compile options:

cc
The C compiler.
-Aa
Use ANSI standard mode (for the C compiler only).
+e
Enables HP value-added features while compiling in ANSI C mode.
-Ipath
Specify the location of the DB2 include files. For example: -I/opt/IBMdb2/v5.0/include
-c
Perform compile only; no link. This book assumes that compile and link are separate steps.

The script file contains the following link options:

cc
Use the compiler to link edit.
-o $1
Specify the name of the object module.
util.o
Include the object file for error checking.
-Lpath
Specify the location of the DB2 runtime shared libraries. For example: -L/opt/IBMdb2/v5.0/lib. If you do not specify the -L option, /usr/lib:/lib is assumed.
-ldb2
Link with the DB2 library.
-lhppa
Specify the HP PA-RISC library (required).

Refer to your compiler documentation for additional compiler options.

To build the sample program updat.sqc, do the following:

  1. Go to the window in which you set your environment variables by running db2profile. Refer to "Setting Your Environment" if you need more information.

  2. Start the database manager on the server, if it is not already running, by entering:
    db2start
    

  3. Build the sample program, connecting to the SAMPLE database, by entering:

    bldcc updat

The result is an executable file updat. You can run the executable file against the SAMPLE database to see how it works by doing the following :

  1. Go to the window in which you set your environment variables by running db2profile.

  2. Start the database manager on the server, if it is not already running, by entering:
    db2start
    

  3. Run the program. If you built the updat sample program, enter:

    updat

Note:To build C applications that do not contain embedded SQL, you can use the script file bldccapi. It contains the same compile and link options as bldcc, but does not connect, prep, bind, or disconnect from the SAMPLE database. It is used to compile and link the DB2 API sample programs written in C.

Building C Stored Procedures

The script file bldccsrv, in sqllib/samples/c, contains the commands to build a C stored procedure. The script file compiles the stored procedure into a shared library that can be called by a client application.

The first parameter, $1, specifies the name of your source file. The second parameter, $2, specifies the name of the database to which you want to connect. The third parameter, $3, specifies the user ID for the database, and $4 specifies the password. Only the first parameter, the source file name, is required. Database name, user ID, and password are optional. If no database name is supplied, the program uses the default sample database.

The script file uses the source file name, $1, for the shared library name.



#! /bin/ksh
# bldccsrv script file
# Build C stored procedure.
# Usage: bldccsrv <prog_name> [ <db_name> [ <userid> <password> ]]
 
# Connect to a database.
if (($# < 2))
then
   db2 connect to sample
elif (($# < 3))
then
   db2 connect to $2
else
   db2 connect to $2 user $3 using $4
fi
 
# Precompile the program.
db2 prep $1.sqc bindfile
 
# Bind the program to the database.
db2 bind $1.bnd
 
# Disconnect from the database.
db2 connect reset
 
# Compile the program.
cc +u1 +Z -Aa +e -I/opt/IBMdb2/v5.0/include -c $1.c
 
# Link the program to create a shared library
ld -b -o $1 $1.o -L/opt/IBMdb2/v5.0/lib -ldb2
 
# Copy the shared library to the sqllib/function subdirectory of the DB2 instance.
# Note: this assumes the user has write permission to this directory.
eval "H=~$DB2INSTANCE"
cp $1 $H/sqllib/function
 
# Note: to use the C++ compiler, substitute the following steps.
# Precompile the program.
# db2 prep $1.sqC bindfile
# Compile the program.
# CC +Z -I/opt/IBMdb2/v5.0/include -c $1.C
# Ensure the stored procedure is coded with extern "C".


Compile and Link Options for bldccsrv

The script file contains the following compile options:

cc
The C compiler.
+u1
Allow unaligned data access. Use only if your application uses unaligned data.
-Aa
Use ANSI standard mode (for the C compiler only).
+Z
Generate position-independent code.
+e
Enables HP value-added features while compiling in ANSI C mode.
-Ipath
Specify the location of the DB2 include files. For example: -I/opt/IBMdb2/v5.0/include.
-c
Perform compile only; no link. This book assumes that compile and link are separate steps.

The script file contains the following link options:

ld
Use the linker to link edit.
-b
Create a shared library rather than a normal executable.
-o $1
Specify the name of the object module.
-Lpath
Specify the location of the DB2 runtime shared libraries. For example: -L/opt/IBMdb2/v5.0/lib. If you do not specify the -L option, /usr/lib:/lib is assumed.
-ldb2
Link with the DB2 library.

Refer to your compiler documentation for additional compiler options.

To build the outsrv.sqc stored procedure, do the following:

  1. Go to the window in which you set your environment variables by running db2profile. Refer to "Setting Your Environment" if you need more information.

  2. Start the database manager on the server, if it is not already running, by entering:
    db2start
    

  3. Build the stored procedure, connecting to the SAMPLE database, by entering:
    bldccsrv outsrv
    

    The script file copies the stored procedure to the server in the path sqllib/function to indicate that the stored procedure is fenced. If you want the stored procedure to be unfenced, you must move it to the sqllib/function/unfenced directory. These paths are in the home directory of the DB2 instance.
    Note:An unfenced stored procedure or UDF runs in the same address space as the database manager and results in increased performance when compared to a fenced stored procedure or UDF, which runs in an address space isolated from the database manager. With unfenced stored procedures or UDFs there is a danger that user code could accidentally or maliciously damage the database control structures. Therefore, you should only run unfenced stored procedures or UDFs when you need to maximize the performance benefits. Ensure these programs are thoroughly tested before running them as unfenced. Refer to the Embedded SQL Programming Guide for more information about fenced and not fenced stored procedures.

  4. If necessary, set the file mode for the stored procedure so the DB2 instance can run it.

Once you build the stored procedure outsrv, you can build the client application that calls the stored procedure. You can build outcli using the bldcc file. Refer to "HP-UX C/C++" for details.

To run the stored procedure, do the following :

  1. Go to the window in which you set your environment variables by running db2profile.

  2. Start the database manager on the server, if it is not already running, by entering:
    db2start
    

  3. Run the sample client application by entering:

    outcli remote_database userid password

    where

    remote_database
    Is the name of the database to which you want to connect. The name could be SAMPLE, or its remote alias, or some other name.

    userid
    Is a valid user ID.

    password
    Is a valid password.

The client application passes a variable to the server program, outsrv, which gives it a value and then returns the variable to the client application.

Building C User-Defined Functions (UDFs)

The script file bldccudf, in sqllib/samples/c, contains the commands to build a UDF. UDFs are compiled like stored procedures, but you do not need to connect to a database or precompile and bind the program.
Note:A UDF does not contain embedded SQL statements. Rather, the application that uses the UDF contains the statements, such as calludf.

The first parameter, $1, specifies the name of your source file. The script file also uses this source file name for the shared library name.



#! /bin/ksh
# bldccudf script file
# Builds sample c UDF library.
# Usage: bldccudf <prog_name>
 
# Compile the program.
cc +u1 +Z -Aa +e -I/opt/IBMdb2/v5.0/include -c $1.c
 
# Link the program and create a shared library.
ld -b -o $1 $1.o -L/opt/IBMdb2/v5.0/lib -ldb2 -ldb2apie
 
# Copy the shared library to the sqllib/function subdirectory of the DB2 instance.
# Note: this assumes the user has write permission to this directory.
eval "H=~$DB2INSTANCE"
cp $1 $H/sqllib/function
 
# Note: to use the C++ compiler, substitute the following step.
# Compile the program.
# CC +Z -I/opt/IBMdb2/v5.0/include -c $1.C
# Ensure the UDF is coded with extern "C".


Compile and Link Options for bldccudf

The script file contains the following compile options:

cc
The C compiler.
+u1
Allow unaligned data access. Use only if your application uses unaligned data.
-Aa
Use ANSI standard mode (for the C compiler only).
+Z
Generate position-independent code.
+e
Enables HP value-added features while compiling in ANSI C mode.
-Ipath
Specify the location of the DB2 include files. For example: -I/opt/IBMdb2/v5.0/include.
-c
Perform compile only; no link. This book assumes that compile and link are separate steps.

The script file contains the following link options:

ld
Use the linker to link edit.
-b
Create a shared library rather than a normal executable.
-o $1
Specify the name of the object module.
-Lpath
Specify the location of the DB2 runtime shared libraries. For example: -L/opt/IBMdb2/v5.0/lib. If you do not specify the -L option, /usr/lib:/lib is assumed.
-ldb2
Link with the DB2 library.
-ldb2apie
Link with the DB2 API Engine library to allow the use of LOB locators.

Refer to your compiler documentation for additional compiler options.

To build the user-defined function udf, do the following:

  1. Go to the window in which you set your environment variables by running db2profile. Refer to "Setting Your Environment" if you need more information.

  2. Build the UDF by entering:
    bldccudf udf
    

    The script file copies the UDF to the server in the path sqllib/function to indicate that the UDF is fenced. If you want the UDF to be unfenced, you must move it to the sqllib/function/unfenced directory. These paths are in the home directory of the DB2 instance.
    Note:An unfenced UDF or stored procedure runs in the same address space as the database manager and results in increased performance when compared to a fenced UDF or stored procedure, which runs in an address space isolated from the database manager. With unfenced UDFs or stored procedures there is a danger that user code could accidentally or maliciously damage the database control structures. Therefore, you should only run unfenced UDFs or stored procedures when you need to maximize the performance benefits. Ensure these programs are thoroughly tested before running them as unfenced. Refer to the Embedded SQL Programming Guide for more information about fenced and not fenced UDFs.

  3. If necessary, set the file mode for the UDF so the DB2 instance can run it.

Once you build udf, you can build the client application, calludf, that calls it. You can build calludf using the bldcc file. Refer to "HP-UX C/C++" for details.

To run the UDF, do the following :

  1. Go to the window in which you set your environment variables by running db2profile.

  2. Start the database manager on the server, if it is not already running, by entering:
    db2start
    

  3. Run the sample calling application by entering:

    calludf

The calling application calls functions from the udf library.

Multi-threaded Applications

Multi-threaded applications on HP-UX need to be linked with libcma.sl. Add -lcma to the end of the link command when building a multi-threaded application.


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