## Command-line startup

You can launch JReport Designer from the Command Prompt window. This method is optional on some platforms (Windows for example) and preferred on others. Using command-line startup enables you to use the command-line syntax options.

`java -Dreporthome=path -classpath path jet.builder.JReport -vError -vDebug -help`

The command line arguments for JReport Designer are described below. Note that the setup process creates several startup batch files which may contain additional parameters.

- -Dreporthome
  Specifies the directory where JReport Designer has been installed. This parameter is required. When you set the report home, upon launching, JReport will try to find jslc.dat and report.ini files in `<install_root>\bin` and check whether they are valid. jslc.dat is the License control file. If you open report.ini, you will find configuration information, including the temp path, template path and the help path. JReport uses the temp path for exporting temporary files, so you should make sure that the temp folder specified in report.ini actually exists.

  Assume that JReport Designer has been installed in `C:\JReport\Designer`, this parameter is `-Dreporthome=C:\JReport\Designer.`

- -classpath path
  Tells the Java interpreter the class path. It is usually used for appending the JReport Designer lib path to the Java class path. For example, assume that JReport Designer has been installed in `C:\JReport\Designer` and Java (JDK1.x.x) has been installed in `C:\java`, this parameter is then:

  `-classpath C:\java\lib\classes.zip;C:\jreport\designer\lib\report.jar;`

- -Djava.compiler=NONE
  Turns off just in time compiling, which sometimes creates problems.
- -Djrpt.outer=true
  Enables JReport Engine to generate an SQL statement with full outer join syntax instead of with abbreviated syntax.
- -Xmx1024m
  Sets the maximum Java heap size.
- Logging and debugging switches
  You can use the following two command switches together to track detail debug and error information.
  - -vError - Enables JReport Designer to output error messages. If you start Designer with this command in the command-line, correspondingly in the LogConfig.properties file, value of the engine Error level will be set to ERROR and value of the engine Trace level will be set to OFF.
  - -vDebug - Enables JReport Designer to output information and warning messages. If you start Designer with this command in the command-line, correspondingly in the LogConfig.properties file, value of the engine Error level will be set to WARN and value of the engine Trace level will be set to INFO.

  You can specify the log file format, such as Text, or HTML. You can then decide whether or not to append the log files to an existing file, or to create a new file. You can even specify the log layout using the abundant options that JReport provides. To do this, you need to edit the file LogConfig.properties in `<install_root>\bin`. For detailed information on how to configure logging and debugging information, see the LogConfig.properites file.

- -help
  Prints the help message.