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     if (command.size() == 1 || !command[1].compare("~") || !command[1].compare("$HOME"))
  47     {           // User wants to cd into $HOME/~.
  48         chdir(getenv("HOME"));
  49         this->cwd = get_cwd();
  50         cwd_changed = true;
  51         return;
  52     }
  53
  54     string cmd;
  55
  56     for(unsigned short int i = 1; i < command.size(); i++)      // TODO: unneeded?
  57         cmd += command[i];
  58
  59     if (chdir(cmd.c_str()))
  60     {
  61                 // Couldn't get to change dirs
  62         cerr << "minish2: cd: " << cmd << ": Arquivo ou diretório não encontrado.\n";
  63     }
  64     else
  65     {
  66                 // chdir worked. and tell Prompt to act accordingly.
  67         this->cwd = get_cwd();      // Update the OpSys OS's current cwd
  68         cwd_changed = true;         // Signals a cwd change to Prompt.
  69     }
  70 }
  71
  72 vector<const char*> make_argv(vector<string>const& in)
  73 {
  74     vector<const char*> out;
  75     out.reserve(in.size() + 1);
  76     for (const auto& s : in)
  77         out.push_back(s.data());
  78     out.push_back(nullptr);
  79     out.shrink_to_fit();
  80     return out;
  81 }
  82
  83 short OpSys::simple_command(vector<string> tokens)
  84 {
  85     int status;
  86     if(is_verbose)
  87     {
  88         cerr << "execvp(\"" << tokens[0] << "\",\"";
  89         for(unsigned int i = 0; i < tokens.size()-1; i++)
  90             cerr << tokens[i] << ' ';
  91         cerr << tokens.back();
  92         cerr << "\");\n";
  93     }
  94
  95
  96     pid_t pid = fork();
  97     if (pid == 0)
  98     {
  99         execvp(tokens[0].c_str(), const_cast<char* const *>(make_argv(tokens).data()));
 100         cerr << tokens[0] << ": command not found.\n";
 101         return 0;        // TODO: exit with cleanup
 102     }
 103     else if (pid < 0)
 104     {
 105         printf("Couldn't fork a process.");
 106         return 0;
 107     }
 108     waitpid(-1, &status, WUNTRACED);
 109     return 1;
 110 }
 111
 112 OpSys::OpSys()
 113 {
 114     cwd = get_cwd();
 115     if(cwd.empty())
 116         cerr << RED_ANSI << "Could not get the current working directory.\n" << RESET_ANSI;
 117
 118     uid_t uid = geteuid();             // Gets the effective ID of the user that started miniSHELL
 119     struct passwd pwent;
 120     struct passwd *pwent_ptr;
 121     char buffer[1024];
 122
 123         // Looks for the UDI on the password databank and saves the result on pwent
 124     getpwuid_r(uid, &pwent, buffer, sizeof buffer, &pwent_ptr);
 125     username = pwent.pw_name;   // Saves username
 126
 127     char hostname[64];
 128     gethostname(hostname, 64);
 129     this->hostname = hostname;
 130 }