C++解析字符串获取参数

• 1.功能说明
• 2.代码

一些软件在运行时，需要一些命令。这里使用通过字符串的方式，来获取软件启动需要的一些参数。

比如：-name1 aaa -name2 bbb
有这样一个字符串，通过解析-name1对应的aaa，-name2对应的bbb；

// ConsoleApplication3.cpp : 此文件包含 "main" 函数。程序执行将在此处开始并结束。
//

#include 
using namespace std;

void GetCanShu(std::string strcmd);
std::string GetSegment(std::string phrase, std::string cmdline);
std::string Left(std::string srcStr, int pos);
std::string Right(std::string srcStr, int pos);
std::string Mid(std::string srcStr, int pos, int len);
std::string TrimLeft(std::string srcStr, const std::string& phrase);
std::string TrimRight(std::string srcStr, const std::string& phrase);
int main()
{

    std::string TestStrCmd = "-name1 aaa -name2 bbb";
    GetCanShu(TestStrCmd);

}

void GetCanShu(std::string strcmd)
{
    std::string sName1 = GetSegment("-name1", strcmd);//
    std::string sName2 = GetSegment("-name2", strcmd);//
    std::cout << sName1 << endl;
    std::cout << sName2 << endl;
}


std::string GetSegment(std::string phrase, std::string cmdline)
{
    std::string str;
    int phrasePos = cmdline.find(phrase, 0);
    if (phrasePos < 0)
    {
        return str;
    }
    int pos = cmdline.find("-", phrasePos + 1);
    if (pos < 0)
    {
        str = Right(cmdline, cmdline.length() - phrasePos);
    }
    else
    {
        str = Mid(cmdline, phrasePos, pos - phrasePos);
    }
    str = TrimLeft(str, phrase);
    str = TrimLeft(str, " ");
    str = TrimLeft(str, """);
    str = TrimRight(str, " ");
    str = TrimRight(str, " "");
    return str;
}
std::string Left(std::string srcStr, int pos)
{
    std::string str;
    if (0 == srcStr.length() || pos < 0)
    {
        return srcStr;
    }

    int i = 0;
    for (; i < pos; i++)
    {
        str += srcStr[i];
    }
    return str;
}
std::string Right(std::string srcStr, int pos)
{
    std::string str;
    if (0 == srcStr.length() || pos < 0)
    {
        return srcStr;
    }
    int i = pos;
    for (; i < srcStr.length(); i++)
    {
        str += srcStr[i];
    }
    return str;
}

std::string Mid(std::string srcStr, int pos, int len)
{
    std::string str;
    if (0 == srcStr.length() || pos < 0 || len < 0)
    {
        return srcStr;
    }
    int i = pos;
    for (; i < (pos + len); i++)
    {
        str += srcStr[i];
    }
    return str;
}
std::string TrimLeft(std::string srcStr, const std::string& phrase)
{
    std::string str;
    std::string::size_type pos = srcStr.find(phrase, 0);
    if (pos == std::string::npos)
    {
        return srcStr;
    }
    str = Right(srcStr, pos + phrase.length());
    return str;
}

std::string TrimRight(std::string srcStr, const std::string& phrase)
{
    std::string str;
    std::string::size_type pos = srcStr.find(phrase, 0);
    if (pos == std::string::npos)
    {
        return srcStr;
    }
    str = Left(srcStr, srcStr.length() - phrase.length());
    return str;
}