#ifndef JULES_UTILS_COMMANDBUF_H
#define JULES_UTILS_COMMANDBUF_H

#include <iostream>
#include <string>
#include <stdexcept>
#include <sstream>

#include <stdio.h>
#include <errno.h>
#include <limits.h>

namespace jules
{
    struct  CommandError : std::runtime_error
    {
        CommandError( const std::string& command0, int errno0);
        ~CommandError() throw() {}
        virtual const char* what()  const throw();
        std::string command;
        int         errornumber;
        std::string message;
    };
    
    struct  CommandBuf  : std::streambuf
    /* A std::streambuf that send text to system() whenever sync() is called.
    sync() will set errno to return value from system() */
    {
        explicit CommandBuf( bool use_exceptions0);

        virtual int sync();
        virtual int overflow( int c);
        virtual ~CommandBuf();
        private:
            std::string buffer;
            bool        use_exceptions;
    };

    struct  Command
    {
        Command(bool use_exceptions0=false);
        operator std::ostream& ();
        std::ostream&   GetStream();
        private:
            CommandBuf      buffer;
            std::ostream    stream;
    };

    void    System( const std::string& cmd);

    std::ostream&   ccmd();
    /* Returns a singleton ostream that sends text to system() whenever it is
    flushed. Use like:
        ccmd() << "ls -l" << flush; // runs `ls -l'.

        int i=34;
        ccmd() << "find ";
        ccmd() << ". -name ";
        ccmd() << "foo" << i << ".txt";
        ccmd() << flush;    // runs `find . -name foo34.txt'.
    When a command is executed, the return from system() is put into errno
    */
    
    std::ostream&   ccmde();
/* As ccmde(), except that errors cause an exception. */
    
}


#endif