如何在C中连接多个C样式字符串？

Question

我必须生成字符串命令来使用微控制器配置设备，因此需要C风格的字符串而不是常规的std::string。

每一步都需要按enter键或是/否enter键，我需要为每一步输入一行代码。代码示例：

#define YES "Y\n"
#define NO "N\n"
#define ENTER "\n"
#define DEFAULT_COMMAND_SIZE 30
    
static char command[DEFAULT_COMMAND_SIZE];

if (getChangePassword()) { // just a function that returns true if password has to be changed
    if (getTelnetPassword() != nullptr) {
        std::strcat(command, YES);
        std::strcat(command, getTelnetPassword()); // password is a char*, same as command
        std::strcat(command, ENTER);
    }
} else {
    std::strcat(command, NO);
}

我可以设法减少重复LOC的数量吗？

Answer 1

使用std::字符串，完成后将其复制到命令中：

演示：

#include <iostream>
#include <string>
#include <string.h>

#define YES "Y\n"
#define NO "N\n"
#define ENTER "\n"
#define DEFAULT_COMMAND_SIZE 30

static char command[DEFAULT_COMMAND_SIZE];

bool getChangePassword()
{
  return true;
}

char *getTelnetPassword()
{
  return (char*)"testpassword";
}

int main()
{
  std::string scommand;
  if (getChangePassword()) { // just a function that returns true if password has to be changed
    if (getTelnetPassword() != nullptr) {
      scommand += YES;
      scommand += getTelnetPassword();
      scommand += ENTER;
    }
  }
  else {
    scommand = NO;
  }

  std::strcpy(command, scommand.c_str());

  std::cout << command;
}