cpp: shell.cpp -- (bugs)

cpp:  shell.cpp -- (bugs)

 

 

 

 

一、原理

 

　　1、实现原理：　　无限循环 +  标准输入（等待输入状态...）；

 

 

 

 

二、代码

[wit@fedora tmp]$ cat  shell.cpp 
#include <iostream>
#include <string>

using namespace std;

void output(string *o)
{
        string ps = "\033[34m[shell@fedora]$ \033[0m";
        int j = 0;

        std::cout << ps << "output: ";
        while(1)
        {
                if ( o[j]==";;" ) { break; }
                std::cout << o[j] << " ";
                j++;
        }
        std::cout << std::endl;
        j = 0;
}

void run()
{
        while(1) {      // wait_while

                string buf[101];
                string ps = "\033[34m[shell@fedora]$ \033[0m";
                string t = "";

                int i = 0;
                cout << ps << "input: ";
                while(1)        // input_while
                {
                        cin >> t;
                        buf[i] = t;
                        i++;

                        // ";;" ends input_while; "exit/quit" ends wait_while
                        if ( t==";;" || t=="exit" || t=="quit" ) { break; }
                }
                i = 0;

                output(buf);

                if( t=="exit" || t=="quit" ) { break; }
        }
}

int main(int argc, char *argv[], char *envp[])
{

        run();

        return 0;

}
[wit@fedora tmp]$ 
[wit@fedora tmp]$ 

 

 

 

  

三、运行

[wit@fedora tmp]$ alias | grep "gpp"
alias gpp='g++ -g -Wall -std=c++20 -o'
[wit@fedora tmp]$ 
[wit@fedora tmp]$ 
[wit@fedora tmp]$ gpp shell shell.cpp && ./shell
[shell@fedora]$ input: hello world ;;
[shell@fedora]$ output: hello world 
[shell@fedora]$ input: one two three four ;;
[shell@fedora]$ output: one two three four 
[shell@fedora]$ input: exit
Segmentation fault (core dumped)
[wit@fedora tmp]$ 
[wit@fedora tmp]$ 

 

 

 

 

四、参考资料：

 

　　1、【Linux】bash项目mybash的实现　　https://blog.csdn.net/qq_53830608/article/details/127518949?spm=1001.2101.3001.6650.1&utm_medium=distribute.pc_relevant.none-task-blog-2~default~CTRLIST~Rate-1-127518949-blog-70148939.235%5Ev40%5Epc_relevant_rights_sort&depth_1-utm_source=distribute.pc_relevant.none-task-blog-2~default~CTRLIST~Rate-1-127518949-blog-70148939.235%5Ev40%5Epc_relevant_rights_sort&utm_relevant_index=2

 

　　2、GNU bash实现机制与源代码简析　　https://www.cnblogs.com/napoleon_liu/archive/2011/04/01/2001886.html