msh-console/console.cpp

#include "console.h"

Commands Console::cmds;

int Console::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 Console::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  launch(args);
  }
  return a;
}



bool undoingLine=false;

void Console::mshEofHandler(int){
    undoingLine = true;
}

string* Console::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>* Console::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;
}

void Console::loop(){
  string* line;
  vector<string>* args;
  int status;
  do {
    bool readSuccess;
    do{
        cout << "MSH$ ";
        try{
            line =  read_line();
            readSuccess = true;
        }
        catch (IsUndoingLineException){
            cout << "\n";
            readSuccess = false;
        }
    }while(!readSuccess);
    args = split_line(line);
    status = execute(args);
  } while (status);
}