#pragma interface
#include <string>
#include <Array.h>

class Program {
protected:
  int pid, status;
  virtual void beforeExec();		// called between fork and exec
  virtual void childExit(int stat);	// called when child exits
  virtual void childStop(int sig);	// called when child stops
  int suid, sgid;
private:
  Array<long> fd;
  Array<string> env;
  Program *next;
  static Program *first;
  static Program *remove(int pid);
  struct Waiter;
public:
  Program();
  Program &runAs(int uid,int gid) { suid = uid; sgid = gid; return *this; }
  Program &setfd(int fd,int dupfd);
  Program &resetfd();	// clear fd map
  int pipein(int fd);
  int pipeout(int fd);
  Program &input(int f,const char *fname);
  Program &output(int fd,const char *fname);
  Program &append(int fd,const char *fname);
  Program &operator<(const char *fname) { return input(0,fname); }
  Program &operator>(const char *fname) { return output(1,fname); }
  Program &operator>>(const char *fname) { return append(1,fname); }
  Program &setenv(const char *envstr);
  int run(const char *cmd);
  int run(const char *prog,const char * const *argv);
  int wait();
  static Program *post(int pid,int status);
  static Program *find(int pid);
  ~Program();
};

/*
  Program pgm;
  pgm.input(0,"testfile").output(1,"test.out").append(2,"errs");
*/