Sources/opsys.cpp

   1 #include "Headers/opsys.h"
   2
   3 #include <sys/param.h>      // MAXPATHLEN
   4 #include <sys/wait.h>       // waitpid
   5 #include <unistd.h>         // getcwd, fork, chdir, geuid, gethostname, execvp
   6 #include <pwd.h>            // struct passwd, getpwuid_r
   7
   8 using std::cin;
   9 using std::cout;
  10 using std::cerr;
  11
  12 OpSys OS;       // Global OpSys variable. Should be accessible to all modules.
  13 bool exit_program = false;
  14
  15 void signal_handler(int s)
  16 {
  17     if (s==SIGINT)
  18     {
  19         cout << "\nSIGINT (Ctrl+C) received. Code " << s << ". Exiting.\n";
  20         exit_program = true;  // We'll do this instead of an exit(0) in order to allow for cleanup.
  21     }
  22
  23     if (s==SIGHUP)
  24     {
  25         cout << "\nSIGHUP received. Code " << s << ". Exiting.\n";
  26         exit_program = true;  // We'll do this instead of an exit(0) in order to allow for cleanup.
  27     }
  28 }
  29
  30 SignalHandler::SignalHandler()
  31 {
  32     signal_action.sa_handler = signal_handler;
  33     sigemptyset(&signal_action.sa_mask);
  34     signal_action.sa_flags = 0;
  35     sigaction(SIGINT, &signal_action, NULL);
  36 }
  37
  38 string OpSys::get_cwd()
  39 {
  40     char temp[MAXPATHLEN];
  41     return getcwd(temp, sizeof(temp)) ? std::string( temp ) : std::string("");
  42 }
  43
  44 void OpSys::change_dir(vector<string> command)
  45 {
  46     string cmd = "";
  47     for(unsigned short int i = 1; i < command.size(); i++)
  48     {
  49         cmd += command[i];
  50     }
  51     if (chdir(cmd.c_str()))
  52     {
  53         cerr << "miniShell: cd: " << cmd << ": Arquivo ou diretório não encontrado\n";
  54     }
  55     else {
  56         get_cwd();
  57         cwd_changed = true;
  58     }
  59 }
  60
  61 vector<const char*> make_argv(vector<string>const& in)
  62 {
  63     vector<const char*> out;
  64     out.reserve(in.size() + 1);
  65     for (const auto& s : in)
  66         out.push_back(s.data());
  67     out.push_back(nullptr);
  68     out.shrink_to_fit();
  69     return out;
  70 }
  71
  72 short OpSys::simple_command(vector<string> tokens)
  73 {
  74     int status;
  75     if(is_verbose)
  76     {
  77         cerr << "execvp(\"" << tokens[0] << "\",\"";
  78         for(unsigned int i = 0; i < tokens.size()-1; i++)
  79             cerr << tokens[i] << ' ';
  80         cerr << tokens.back();
  81         cerr << "\");\n";
  82     }
  83
  84
  85     pid_t pid = fork();
  86     if (pid == 0)
  87     {
  88         //printf("execlp(%s, %s, NULL);", bincmd.c_str(), command.c_str());
  89         execvp(tokens[0].c_str(), const_cast<char* const *>(make_argv(tokens).data()));
  90         cerr << tokens[0] << ": command not found.\n";
  91         return 0;        // TODO: exit with cleanup
  92     }
  93     else if (pid < 0)
  94     {
  95         printf("Couldn't fork a process.");
  96         return 0;
  97     }
  98     waitpid(-1, &status, WUNTRACED);
  99     return 1;
 100 }
 101
 102 OpSys::OpSys()
 103 {
 104     cwd = get_cwd();
 105     if(cwd.empty())
 106         cerr << RED_ANSI << "Could not get the current working directory.\n" << RESET_ANSI;
 107
 108     uid_t uid = geteuid();             // Gets the effective ID of the user that started miniSHELL
 109     struct passwd pwent;
 110     struct passwd *pwent_ptr;
 111     char buffer[1024];
 112
 113         // Looks for the UDI on the password databank and saves the result on pwent
 114     getpwuid_r(uid, &pwent, buffer, sizeof buffer, &pwent_ptr);
 115     username = pwent.pw_name;   // Saves username
 116
 117     char hostname[64];
 118     gethostname(hostname, 64);
 119     this->hostname = hostname;
 120 }