32.4 Command line help

The OEInterface object can has a significant amount of information, default values, text descriptions etc, about the parameters it holds. This information can be made accessible from the command line using the OECheckHelp function. This function is described in detail in the API documentation, but in general is simply check if the first argument on the command line (argv[1]) is "help", and if it is I supplies instructions on how to access the various help functions. If no help is requested (i.e., argv[1] isn't "help) the function is a no-op.

Given the following program

Chapter 32 - Example 6 : cpp file

#include "oeplatform.h"
#include "oesystem.h"

//Defines static const unsigned char* array InterfaceData
#include "ch32-6.itf"

using namespace OEPlatform;
using namespace OESystem;

int main(int argc, char** argv)
{
  OEInterface itf;
  OEConfigure(itf,InterfaceData);
  if (OECheckHelp(itf,argc,argv)) return 0;
  OEParseCommandLine(itf,argc,argv);
  OEWriteSettings(itf,oeout,true);
  return 0;
}

and text configuration file

Chapter 32 - Example 6 : txt configuration file

!PARAMETER -x
  !TYPE float
  !DEFAULT 0.0
  !VISIBILITY simple
  !BRIEF First variable
!END

!PARAMETER -y
  !TYPE float
  !DEFAULT 0.0
  !BRIEF Second variable
!END

!PARAMETER -op
  !TYPE string
  !BRIEF Operation to perform on x and y
  !DETAIL
    The operation performed is

      x <-op> y

    So if -op is 'add' the operation is

      x + y
  !VISIBILITY normal
!END

Calling the program with "help" as the first argument gives and no further arguments gives the following.

> ch32-6 --help
Help functions:
  ch32-6 --help simple      : Get a list of simple parameters
  ch32-6 --help all         : Get a complete list of parameters
  ch32-6 --help defaults    : List the defaults for all parameters
  ch32-6 --help <parameter> : Get detailed help on a parameter
  ch32-6 --help html        : Create an html help file for this program

>

The specific help function return the following output

> ch32-6 --help simple
Simple parameter list
    -x : First variable
    -y : Second variable

> ch32-6 --help all
Complete parameter list
    -op : Operation to perform on x and y
    -x : First variable
    -y : Second variable

> ch32-6 --help defaults
Default settings
    -op : add
    -x : 0.000000
    -y : 0.000000

> ch32-6 --help -x
Contents of parameter -x
    Type : floatDefault : 0.000000
    Simple : true
    Required : false
    Brief : First variable

> ch32-6 --help -y
Contents of parameter -y
    Type : floatDefault : 0.000000
    Simple : true
    Required : false
    Brief : Second variable

> ch32-6 --help -op
Contents of parameter -op
    Type : string
    Simple : false
    Required : false
    Brief : Operation to perform on x and y
    Detail
            The operation performed is

              x <-op> y

            So if -op is 'add' the operation is

              x + y

> ch32-6 --help html
Creating 'ch32-6_help.html'

The difference between the simple and all help is that all lists every parameter with a visibility setting of "simple" or "normal", while simple only lists parameters with a visibility setting of "simple". "simple" is the default visibility if !VISIBILITY isn't specified. Calling the html help creates an html file with all the available help content from the OEInterface.

				OEChem - C++ Theory Manual Version 1.3.1

				OEChem - C++ Theory Manual Version 1.3.1