[cpp]: my_systemcall()

[cpp]:  my_systemcall()

 

 

 

 

一、说明

 

　　1、　　C语言可以用【struct】替代C++的【class】。

 

 

 

二、代码

#include <iostream>
#include <string>


// system_calls tables
class c_sys_call_table
{
public:
    c_sys_call_table(int no) 
    { 
        bool j = mf_check(no); 
        if ( true == j ) 
        { 
            mf_run(no);
        }
        else
        {
            std::cout <<"[error]#    systemcall(no=" << no << "):    NOT FOUND." << std::endl ;    
        }
    }
    c_sys_call_table(std::string name) 
    { 
        bool j = mf_check(name); 
        if ( true == j ) 
        { 
            mf_run(name);
        }
        else
        {
            std::cout <<"[error]#    systemcall(name=" << name << "):    NOT FOUND." << std::endl ; 
        }
    }
    bool mf_check(int no) 
    {
        return ( (no >= 0) && (no < 5) ) ;
    }
    
    bool mf_check(std::string name)
    {
        for(int i=0; i<5; i++)
        {
            if (name == mv_st[i]) { return true ; } 
        }
        
        return false ;
    }
    
    void mf_run(int no)
    {
        std::cout <<"[os]#    " << mv_st[no] <<"():    system_call is running !" << std::endl ;
    }
    void mf_run(std::string name)
    {
        std::cout <<"[os]#    " << name <<"():    system_call is running !" << std::endl ;
    }
private:
    std::string  mv_st[5] = { "init", "system", "brk", "exec", "exit" } ;
};


// system_call packages
class c_syscalls
{
private:
    int mv_sys_no = -1 ;
    std::string mv_sys_name = "" ;
public:
    c_syscalls(int i):mv_sys_no(i){ c_sys_call_table sci(mv_sys_no) ; }
    c_syscalls(std::string s):mv_sys_name(s){ c_sys_call_table sn(mv_sys_name) ; }
    void mf_msg()
    {
        if ( mv_sys_no >= 0 )
        {
            std::cout << "[os]#    system_call_no := " << mv_sys_no << std::endl ;    
        }
        else
        {
            std::cout << "[os]#    system_call_no NOT FOUND := " << mv_sys_no << std::endl ;   
        }
        
        if ( mv_sys_name != "" )
        {
            std::cout << "[os]#    system_call_name := " << mv_sys_name << std::endl ;   
        }
        else
        {
            std::cout << "[os]#    system_call_name NOT FOUND := " << mv_sys_name << std::endl ;       
        }
    }
};


// system call initialization and run
void syscall(int i)
{
    c_syscalls si(i) ;
}
void syscall(std::string  n)
{
    c_syscalls sn(n) ;
}


// entry port
int main()
{
    syscall(1) ;
    syscall("exit") ;
    
    syscall(5) ;
    syscall("big") ;
    
    return 0 ;
}

 

 

三、运行

g++ -std=c++20 -O2 -Wall -pedantic -pthread main.cpp && ./a.out


[os]#    system():    system_call is running !
[os]#    exit():    system_call is running !
[error]#    systemcall(no=5):    NOT FOUND.
[error]#    systemcall(name=big):    NOT FOUND.

 

 

四、参考文档

 

　　1、无