msh-console/main.cpp

/**
 * Edit of lsh from https://github.com/brenns10/msh.git rewritten in C++
 * by Claudio Maggiobi
 */

#include <sys/wait.h>
#include <unistd.h>
#include <cstdlib>
#include <sstream>
#include <cstdio>
#include <string>
#include <cstring>
#include <vector>
#include <iostream>
#include <csignal>
#include <commands.h>
using namespace std;

Commands cmds;

int msh_launch(vector<string>* args)
{
    pid_t pid;
    int status;

    pid = fork();
    if (pid == 0) {
    vector<char *> argv(args->size() + 1);
    size_t i;
    for (i = 0; i != args->size()-1; ++i)
    {
        argv[i] = &(args->operator[](i)[0]);
    }
    argv[i] = NULL;
    if(execvp(argv[0], argv.data()) == -1) {
        cerr << "msh: command " << args->operator [](0) << " not found\n";
    }
    exit(EXIT_FAILURE);
    }
    else if (pid < 0) {
        // Error forking
        cerr << "msh: error forking\n";
    }
    else {
        // Parent process

        do {
            waitpid(pid, &status, WUNTRACED);
        } while (!WIFEXITED(status) && !WIFSIGNALED(status));
    }
    return 1;
}

int msh_execute(vector<string>* args)
{
  if (args->operator [](0) == "\0") {
    // An empty command was entered.
    return 1;
  }
  int a;
  try {
      a=cmds.launch(args);
  }
  catch (CommandNotFoundException){
    return msh_launch(args);
  }
  return a;
}

class IsUndoingLineException {};

bool undoingLine=false;

void mshEofHandler(int){
    undoingLine = true;
}

string* msh_read_line()
{
    string* buffer = new string();
    struct sigaction *sa = new struct sigaction();
    sa->sa_handler = mshEofHandler;
    sa->sa_flags = 0; // not SA_RESTART!;
    sigaction(SIGINT, sa, NULL);

    getline(cin,*buffer); // get command
    cin.clear();  // clear flags

    if(undoingLine){
        undoingLine=false;
        throw IsUndoingLineException();
    }

    return buffer;
}

vector<string>* msh_split_line(string* line)
{
    vector<string>* tokens = new vector<string>();
    string ln = *line;
    istringstream is(ln);
    int i;
    for(i=0; getline(is, ln, ' '); i++){
        tokens->push_back(ln);
    }
    tokens->push_back("\0");
    return tokens;
}

inline void msh_loop(void)
{
  string* line;
  vector<string>* args;
  int status;

  do {
    bool readSuccess;
    do{
        cout << "MSH$ ";
        try{
            line = msh_read_line();
            readSuccess = true;
        }
        catch (IsUndoingLineException){
            cout << "\n";
            readSuccess = false;
        }
    }while(!readSuccess);
    args = msh_split_line(line);
    status = msh_execute(args);

  } while (status);
}

int main(int argc, char **argv)
{
  // Load config files, if any.

  // Run command loop

  msh_loop();

  // Perform any shutdown/cleanup.

  return EXIT_SUCCESS;
}