直接上代码了

#pragma pack(1)
struct _st_v2x_testingdata
{
    int len;
    uint8_t cmd;
    uint8_t data_type;
    char ID[8];
    uint64_t sign_verify_time;
    uint8_t sign_verify_result;
    uint64_t send_receive_time;
    int32_t AID;
    int32_t CBR;
    int32_t msgCnt;
    uint64_t secMark;
    uint32_t speed;
    uint32_t longitude;
    uint32_t latitude;
    int32_t heading;
    char dsmp_payload[0];
};
#pragma pack()

还是直接上代码了

string get_bcd_str()
{
    string strret;
    char chtimestamp[32]={0};

    struct timeval tv;
    struct tm *tm;

    gettimeofday(&tv, NULL);
    tm = localtime(&tv.tv_sec);

    sprintf(chtimestamp, "%04d-%02d-%02d %02d:%02d:%02d.%03d",
            tm->tm_year + 1900,
            tm->tm_mon + 1,
            tm->tm_mday,
            tm->tm_hour,
            tm->tm_min,
            tm->tm_sec,
            (int) (tv.tv_usec / 1000)
        );

    strret = chtimestamp;
    return strret;
}

gflags是google的一个开源的处理命令行参数的库,使用c++开发

#include <iostream>
#include <string>

#include <gflags/gflags.h>

DEFINE_bool(a_bool_flag, true, "A Bool Flag");
DEFINE_string(ipaddr, "127.0.0.1", "IPAddress String");
DEFINE_int32(portno, 4000, "Port NO.");

static bool ipaddr_validator(
        const char* flagname,
        const std::string& ipaddr) {
    if (ipaddr.size() >= 7 && ipaddr.size() <= 15) {
        return true;
    }

    std::cerr << flagname << std::endl;
    std::cerr << "Invalid IP address: " << ipaddr << std::endl;

    return false;
}

static bool port_validator(
        const char* flagname,
        google::int32 portno) {
    if (portno > 0 && portno < 65536) {
        return true;
    }

    std::cerr << flagname << std::endl;
    std::cerr << "Invalid port: " << portno << std::endl;

    return false;
}

void func_use_flags() {
    std::cout << FLAGS_a_bool_flag << std::endl;
    std::cout << FLAGS_ipaddr << std::endl;
    std::cout << FLAGS_portno << std::endl;
}

int main(int argc, char* argv[]) {
    std::cout << google::RegisterFlagValidator(&FLAGS_ipaddr, &ipaddr_validator) << std::endl;;
    std::cout << google::RegisterFlagValidator(&FLAGS_portno, &port_validator) << std::endl;
    std::cout << "before ParseCommandLineFlags. argc : " << argc << std::endl;
    for (int i = 0; i < argc; ++i) {
        std::cout << "argv[" << i << "] : " << argv[i] << std::endl;
    }
    int r = google::ParseCommandLineFlags(&argc, &argv, false);
    std::cout << r << std::endl;
    std::cout << "after ParseCommandLineFlags. argc : " << argc << std::endl;
    for (int i = 0; i < argc; ++i) {
        std::cout << "argv[" << i << "] : " << argv[i] << std::endl;
    }

    func_use_flags();

    return 0;
}

gflags下载，安装，使用
下载地址：
官方主页：https://github.com/gflags/gflags
当前最新下载地址

wget https://github.com/gflags/gflags/archive/refs/tags/v2.2.2.tar.gz
tar xvf v2.2.2.tar.gz
cd gflags-2.2.2/
mkdir build
cd build
cmake -DBUILD_SHARED_LIBS=ON -DBUILD_STATIC_LIBS=ON -DINSTALL_HEADERS=ON -DINSTALL_SHARED_LIBS=ON -DINSTALL_STATIC_LIBS=ON -DCMAKE_INSTALL_PREFIX=$(pwd)/../../install ..

不指定安装目录，就直接安装到系统里面了。
示例代码

#include "bits/stdc++.h"
using namespace std;
#include <gflags/gflags.h>
DEFINE_bool(big_menu, true, "Include 'advanced' options in the menu listing");
DEFINE_string(languages, "english,french,german",
        "comma-separated list of languages to offer in the 'lang' menu");
int main(int argc, char* argv[])
{
    google::SetVersionString("V1.0.0@const.net.cn");
    google::SetUsageMessage("-help ");
    google::ParseCommandLineFlags(&argc, &argv, true);
    std::cout << FLAGS_big_menu << std::endl;
    std::cout << FLAGS_languages << std::endl;
    return 0;
}

g++ test_gflags.cpp -o test_gflags -I ./install/include -L ./install/lib -lgflags

运行

./test_gflags -version

test_gflags version V1.0.0@const.net.cn

./test_gflags -helpshort

test_gflags: -help

Flags from test_gflags.cpp:

-big_menu (Include 'advanced' options in the menu listing) type: bool
  default: true
-languages (comma-separated list of languages to offer in the 'lang' menu)
  type: string default: "english,french,german"

./test_gflags -big_menu=false
0
english,french,german

./test_gflags -big_menu=true

1
english,french,german

./test_gflags -big_menu=true -languages=zh-cn

1
zh-cn

gflags 定义变量供多个文件使用
使用DECLARE_xxx与DEFINE_xxx方式，DECLARE_xxx在头文件中，DEFINE_xxx在源文件中。
示例：file flags.h

#ifndef FLAGS_H
#define FLAGS_H
#include "gflags/gflags.h"
#include <string>
using std::string;
DECLARE_int32(int32_var);
DECLARE_int64(int64_var);
DECLARE_bool(bool_var);
DECLARE_double(double_var);
DECLARE_uint32(uint32_var);
DECLARE_uint64(uint64_var);
DECLARE_string(string_var);
#endif 

示例：file flags.cpp

#include "flags.h"
DEFINE_int32(int32_var, 0, "int32 变量示例，默认为0");
DEFINE_int64(int64_var, 0, "int64 变量示例，默认为0");
DEFINE_bool(bool_var, true, "bool 变量示例，默认为true");
DEFINE_double(double_var, 0.0, "double 变量示例，默认为0.0");
DEFINE_uint32(uint32_var, 0, "uint32 变量示例，默认为0");
DEFINE_uint64(uint64_var, 0, "uint64 变量示例，默认为0");
DEFINE_string(string_var, "", "string 变量示例，默认为空");

示例使用：

#include "bits/stdc++.h"
#include <gflags/gflags.h>
#include "flags.h"
using namespace std;
int main(int argc, char* argv[])
{
    google::SetVersionString("V1.0.0@const.net.cn");
    google::SetUsageMessage("-help ");
    google::ParseCommandLineFlags(&argc, &argv, true);
    std::cout << FLAGS_string_var<< std::endl;
    std::cout << FLAGS_int32_var<< std::endl;
    std::cout << FLAGS_bool_var<< std::endl;
    return 0;
}

运行结果：

./test_gflags -help
Flags from flags.cpp:
    -bool_var (bool 变量示例，默认为true) type: bool default: true
    -double_var (double 变量示例，默认为0.0) type: double default: 0
    -int32_var (int32 变量示例，默认为0) type: int32 default: 0
    -int64_var (int64 变量示例，默认为0) type: int64 default: 0
    -string_var (string 变量示例，默认为空) type: string default: ""
    -uint32_var (uint32 变量示例，默认为0) type: uint32 default: 0
    -uint64_var (uint64 变量示例，默认为0) type: uint64 default: 0