OFtutorial02_commandLineArgumentsAndOptions

代码：

argList::addNote
(
    "Demonstrates how to handle command line options.\n"
    "\n"
    "Input arguments:\n"
    "----------------\n"
    "  someWord - does stuff\n"
    "  someScalar - does more things\n"
    );

作用：

定义应用的帮助文件

代码：

argList::noParallel();
argList::validArgs.append("someWord");
argList::validArgs.append("someScalar");

作用：

准备命令列表

代码：

argList::addOption // string variable
(
    "dict",
    "word",
    "Path to an additional dictionary (not really used now)"
);

argList::addBoolOption // on/off depending on whether option is given or not
(
    "someSwitch",
    "Switches from A to B"
);

argList::addOption // integer variable
(
    "someInt",
    "label",
    "Optional integer"
);

作用：

准备选项

可以添加不同的数据类型

代码：

Foam::argList args(argc, argv);
if (!args.checkRootCase())
{
    Foam::FatalError.exit();
}

作用：

创建命令列表。

这个操作一般在setRootCase.H文件中定义

需要包含该头文件#include setRootCase.H

代码：

const word someWord = args[1];
const scalar someScalar = args.argRead<scalar>(2);
Info << "Got argument word " << someWord << " and scalar " << someScalar << endl;

作用：

读入数据并输出

注：内置的方法可以把字符串转化为其他的数据格式

代码：

fileName dictPath("./system/defaultDict");

作用：

默认的dictionary路径

代码：

if (args.optionFound("dict"))
{
    args.optionReadIfPresent("dict", dictPath);
    Info << "Got an override flag for dictionary path" << endl;
}
Info << "Would read dict from " << dictPath << endl;

作用：

根据命令行的选项，有条件执行

如果args找到了"dict"则在上文设置的dictPath中读入选项。

代码：

const bool someConstBool = args.optionFound("someSwitch");
Info << "Boolean switch set to " << someConstBool << endl;

作用：

调整选项

如果在args中找到了someSwitch则把bool值设置为真

代码：

label someInt(0);
args.optionReadIfPresent("someInt", someInt);
Info << "Integer option value " << someInt << endl;

作用：

读取数据的值，与字符串的处理几乎完全一致。

完整代码：

/*---------------------------------------------------------------------------*\
  =========                 |
  \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
   \\    /   O peration     |
    \\  /    A nd           | Copyright (C) 2011-2015 OpenFOAM Foundation
     \\/     M anipulation  |
-------------------------------------------------------------------------------
License
    This file is part of OpenFOAM.

    OpenFOAM is free software: you can redistribute it and/or modify it
    under the terms of the GNU General Public License as published by
    the Free Software Foundation, either version 3 of the License, or
    (at your option) any later version.

    OpenFOAM is distributed in the hope that it will be useful, but WITHOUT
    ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
    FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
    for more details.

    You should have received a copy of the GNU General Public License
    along with OpenFOAM.  If not, see <http://www.gnu.org/licenses/>.

\*---------------------------------------------------------------------------*/

#include "fvCFD.H"

int main(int argc, char *argv[])
{
    // ===
    // Define the help message for this application
    argList::addNote
    (
        "Demonstrates how to handle command line options.\n"
        "\n"
        "Input arguments:\n"
        "----------------\n"
        "  someWord - does stuff\n"
        "  someScalar - does more things\n"
    );

    // prepare argument list
    argList::noParallel();
    argList::validArgs.append("someWord");
    argList::validArgs.append("someScalar");

    // prepare options
    argList::addOption // string variable
    (
        "dict",
        "word",
        "Path to an additional dictionary (not really used now)"
    );

    argList::addBoolOption // on/off depending on whether option is given or not
    (
        "someSwitch",
        "Switches from A to B"
    );

    argList::addOption // integer variable
    (
        "someInt",
        "label",
        "Optional integer"
    );

    // ===
    // create argument list
    // This is normally defined inside setRootCase.H
    // #include "setRootCase.H"
    Foam::argList args(argc, argv);
    if (!args.checkRootCase())
    {
        Foam::FatalError.exit();
    }

    // ===
    // read arguments
    const word someWord = args[1];
    // NOTE: the built-in method for converting strings to other data types
    const scalar someScalar = args.argRead<scalar>(2);

    Info << "Got argument word " << someWord << " and scalar " << someScalar << endl;

    // ===
    // read options
    // default path to some dictionary
    fileName dictPath("./system/defaultDict");

    // conditional execution based on an option being passed
    if (args.optionFound("dict"))
    {
        args.optionReadIfPresent("dict", dictPath);
        Info << "Got an override flag for dictionary path" << endl;
    }
    Info << "Would read dict from " << dictPath << endl;

    // switch option
    const bool someConstBool = args.optionFound("someSwitch");
    Info << "Boolean switch set to " << someConstBool << endl;

    // numeric value option - same as string variables really
    label someInt(0);
    args.optionReadIfPresent("someInt", someInt);
    Info << "Integer option value " << someInt << endl;
    
    Info<< "End\n" << endl;

    return 0;
}


// ************************************************************************* //