TASK
打造一个绝无伦比的 xxx-super-shell (xxx 是你的名字)，它能实现下面这些功能：
- 实现管道（也就是 |）
- 实现输入输出重定向（也就是 < > >>）
- 要求在管道组合命令的两端实现重定向运算符
# 需要实现的功能
cat < 1.txt | grep -C 10 abc | grep -Lefd | tac >> 2.txt
# 不需要实现的功能
cat < 1.txt | grep -C 10 abc > test1.txt | test2.txt > grep -L efd | tac >> 2.txt-
实现后台运行（也就是 &）
-
实现 cd，要求支持能切换到绝对路径、相对路径和支持 cd -
-
屏蔽一些信号（如 ctrl + c 不能终止）
-
界面美观
-
开发过程记录、总结、发布在个人博客中
要求：
-
不得出现内存泄漏、内存越界等错误 - 学会如何使用 gdb 进行调试，使用 valgrind 等工具进行检测
ish.cpp
#include"shell.hpp"
#define DB 1 // DB为1时,进入debug模式 不屏蔽信号
int main()
{
ish sh;
Prompt pr;
Command cmd;
void show();
show();
if(!DB)nosignal();
system("clear");
while(true)
{
pr.PrintPrompt();
sh.GetCommand();
cmd.Process();
sh.LineClear();
}
return -1;
}shell.hpp
#include<iostream>
#include<string>
#include<vector>
#include<unistd.h>
#include<sys/ioctl.h>
#include<signal.h>
#include<string.h>
#include<sys/wait.h>
#include<fcntl.h>
#include<pwd.h>
using namespace std;
void nosignal();
vector<string> split(string,char);
vector<char*>fromStoC(vector<string>);
bool isRedirect(string);
class ish
{
friend vector<string>split(string,char);
friend bool isRedirect(string);
public:
void GetCommand();
void LineClear();
bool iscd();
ish()
{
char path[64];
realpath(".",path);
wdPath = path;
setenv("OWD",".",1);
char hostname[64];
gethostname(hostname,64);
hostName = hostname;
int userid = getuid();
struct passwd * pwd = getpwuid(userid);
userName = pwd->pw_name;
}
protected:
string hostName;
string userName;
string gitHEAD = "master";
static string wdPath;
static string line;
static vector<string>argv;
static vector<int *>fds;
static int ExeCount;
static bool pipeError;
int PromptLen;
static bool isError;
};
class Prompt: public ish
{
public:
void PrintPrompt();
Prompt()
{
failed = "\e[100m\e[31m ✘\e[39m";
isError = false;
}
private:
string colors;
string output;
string failed;
};
class Command: public Prompt
{
public:
bool isClear();
void isExit();
void ExeCommand();
void Process();
};using.cpp
#include"shell.hpp"
void show()
{
string showName[9];
showName[0] = " __ __ ";
showName[1] = " /\\ \\ __ /\\ \\ ";
showName[2] = " ___\\ \\ \\___ ___ ___ __ __ /\\_\\ ____\\ \\ \\___ ";
showName[3] = " / __`\\ \\ _ `\\ /' __` __`\\/\\ \\/\\ \\ \\/\\ \\ /',__\\ \\ _ `\\ ";
showName[4] = "/\\ \\L\\ \\ \\ \\ \\ \\ /\\ \\/\\ \\/\\ \\ \\ \\_\\ \\ \\ \\ \\/\\__, `\\ \\ \\ \\ \\ ";
showName[5] = "\\ \\____/\\ \\_\\ \\_\\ \\ \\_\\ \\_\\ \\_\\/`____ \\ \\ \\_\\/\\____/ \\ \\_\\ \\_\\";
showName[6] = " \\/___/ \\/_/\\/_/ \\/_/\\/_/\\/_/`/___/> \\ \\/_/\\/___/ \\/_/\\/_/";
showName[7] = " /\\___/ ";
showName[8] = " \\/__/ ";
for(int i = 0;i<9;i++)
{
printf("\e[9%dm",i);
cout<<showName[i]<<endl;
usleep(110000);
}
cout<<"输入 '?' 以获取帮助"<<endl;
cout<<"请按任意键继续";
getchar();
}
string ish::wdPath;
string ish::line;
vector<string> ish::argv;
bool ish::isError = false;
int ish::ExeCount = 0;
vector<int *> ish::fds;
bool ish::pipeError = false;
void help();
vector<string> split(string s,char ch)
{
vector<string>result;
int pos = 0;
while (s[pos]==ch)
pos++;
while (pos< s.size())
{
int n = 0;
while (s[pos+n]!=ch&&pos+n<s.size())
{
n++;
}
result.push_back(s.substr(pos,n));
pos += n;
while (s[pos] ==ch&&pos<s.size())
{
pos++;
}
}
return result;
}
vector<char *> fromStoC(vector<string>s)
{
vector<char *>c;
for(int i = 0;i<s.size();i++)
{
char * buf = new char[s[i].size()];
strcpy(buf,s[i].c_str());
c.push_back(buf);
}
return c;
}
void nosignal()
{
signal(SIGINT,SIG_IGN);
}
bool isRedirect(string str)
{
if(str.find('<')==-1&&str.find('>')==-1)
return 0;
return 1;
}
void Prompt::PrintPrompt()
{
output = "\e[100m" + (string)" " + userName + "@" + hostName + " " + (string)"\e[90m" + (string)"\e[104m" + "" + " " + wdPath + " " + "\e[43m" + "\e[34m" + "" + "\e[33m" + " " + gitHEAD + " ± " + "\e[33m" + "\e[49m" + "" + "\e[39m\e[0m";
isError ? (cout<< failed + output << " ") : cout << output << " ";
isError = false;
}
void ish::GetCommand()
{
FLAG:
getline(cin,line); // get a line of command
int pos = 0;
while (line[pos] == ' ')
{
pos ++;
}
line = line.substr(pos);
argv = split(line,' ');
if(line.empty())
{
Prompt news;
news.PrintPrompt();
goto FLAG;
}
}
void ish::LineClear()
{
line.clear();
}
bool Command::isClear()
{
if(line == "clear"||line == "cls")
{
system("clear");
return true;
}
return false;
}
void Command::isExit()
{
if(line == "exit")
exit(EXIT_SUCCESS);
}
bool isH(string line)
{
if(line=="?")
{
help();
return true;
}
if(line=="!")
{
show();
return true;
}
return false;
}
void Command::Process()
{
if(isH(line))
return;
vector<int *>vpipes;
vector<string>v = split(line,'|');
if(v.size()==1)
{
argv = split(v[0],' ');
ExeCommand();
}
else
{
if(v.size()==0)
{
cout<<"ish: | 解析错误"<<endl;
isError = 1;
return;
}
for(int i = 0;i<v.size()-1;i++)
{
int * fd = new int[2];
pipe(fd);
fds.push_back(fd);
}
for(int i = 0;i<v.size();i++)
{
argv = split(v[i],' ');
ExeCommand();
if(ExeCount != 0)close(fds[ExeCount-1][0]);
if(ExeCount != fds.size())close(fds[ExeCount][1]);
ExeCount ++;
}
ExeCount = 0;
fds.clear();
}
}
void Command::ExeCommand()
{
vector<char *>ar = fromStoC(argv);
if(isClear()||iscd())
return;
isExit();
pid_t pid = fork();
if(pid == 0)
{
if(ExeCount != 0)dup2(fds[ExeCount-1][0],0);
if(ExeCount != fds.size())dup2(fds[ExeCount][1],1);
if(isRedirect(line))
{
if(argv.size()<3)
{
cout<<"ish: 重定向 解析错误"<<endl;
isError = 1;
return;
}
for(int i = 0;i<argv.size();i++)
{
if(argv[i]=="<")
{
int fd = open(argv[i+1].data(),O_RDONLY);
dup2(fd,0);
ar.erase(ar.begin()+i);
close(fd);
}
if(argv[i]==">")
{
int fd = open(argv[i+1].data(),O_RDWR|O_CREAT|O_TRUNC,S_IRUSR|S_IWUSR);
dup2(fd,1);
ar.erase(ar.begin()+i);
ar.erase(ar.begin()+i+1);
close(fd);
}
if(argv[i]==">>")
{
int fd = open(argv[i+1].data(),O_RDWR|O_APPEND|O_CREAT,S_IRUSR|S_IWUSR);
dup2(fd,1);
ar.erase(ar.begin()+i);
ar.erase(ar.begin()+i+1);
close(fd);
}
}
}
ar.push_back(NULL);
if(strcmp(ar[0],"ls")==0)
{
ar.pop_back();
ar.push_back((char *)"--color=auto");
ar.push_back(NULL);
}
if(execvp(ar[0],ar.data())==-1)
{
isError = true;
cout<<"ish: command not found: "<<argv[0]<<endl;
return;
}
}
wait(&pid);
}
bool ish::iscd()
{
if(argv[0]!="cd")
return 0;
char * homepath = getenv("HOME");
if(argv[0] == "cd"&&argv.size()==1)
argv.push_back(homepath);
if(argv[1]=="-")
{
char * lpath = getenv("OWD");
cout<<lpath<<endl;
if(chdir(lpath)==-1)
{
isError = true;
}
wdPath = lpath;
return 1;
}
char rp[1000];
realpath(argv[1].c_str(),rp);
if(chdir(argv[1].c_str())==-1)
{
cout<<"cd: path not found"<<endl;
isError = true;
return 1;
}
setenv("OWD",wdPath.c_str(),1);
wdPath = rp;
return 1;
}
void help()
{
cout<<"你知道吗？输入!可以观看炫酷的动画。"<<endl;
}
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