main.cpp

// Copyright 2016 Hunter L. Allen
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
#include <string>
#include <memory>
#include <vector>

#include "shell-readline.hpp"
#include "shell_bison.hh"
#include "command.hpp"

extern FILE * yyin;
extern FILE * yyout;

extern int yylex();
extern int yyparse();

extern void yyrestart(FILE * in);
extern void yyerror(const char * s);
extern read_line reader;
std::shared_ptr<std::vector<std::string>> SimpleCommand::history = nullptr;
std::shared_ptr<std::vector<job>> SimpleCommand::p_jobs = nullptr;

int main()
{
  bool is_interactive = false;
  std::string expanded_home = tilde_expand("~/.yashrc");

  auto rcfile = std::shared_ptr<char>(strndup(expanded_home.c_str(), expanded_home.size()), free);

  yyin = fopen(rcfile.get(), "r");

  /* From Brian P. Hays */
  if (yyin != nullptr) {
    Command::currentCommand.printPrompt = false;
    yyparse();
    fclose(yyin);

    yyin = stdin;
    yyrestart(yyin);
    Command::currentCommand.printPrompt = true;
  }
  Command::currentCommand.set_interactive((is_interactive = isatty(0)));
  if (is_interactive) {
    /* loop until we are in the foreground */
    for (; tcgetpgrp(STDIN_FILENO) != (Command::currentCommand.m_pgid = getpgrp()); ) {
      if (kill(0, SIGTTIN) < 0) {perror("kill");}
    }

    /* go to our process group */
    pid_t shell_pgid = getpid();
    if ((shell_pgid != getpgrp()) && setpgid(0, shell_pgid) < 0) {perror("setpgid");}

    Command::currentCommand.m_shell_pgid = shell_pgid;
    /* Ignore interactive and job-control signals */
    signal(SIGINT, SIG_IGN);
    signal(SIGQUIT, SIG_IGN);
    signal(SIGTSTP, SIG_IGN);
    signal(SIGTTIN, SIG_IGN);
    signal(SIGTTOU, SIG_IGN);
    signal(SIGCHLD, SIG_IGN);

    tcsetpgrp(STDIN_FILENO, Command::currentCommand.m_shell_pgid);
    tcgetattr(STDIN_FILENO, &reader.oldtermios);
  }

  Command::currentCommand.prompt();
  yyparse();

  return 0;
}