add convenience function to get the output of strerror(errno) as c++ string

#include "utils.h"

#include <cstring>

#include <cstdlib>

#include <cerrno>

#include "lammps.h"

#include "error.h"

#include "tokenizer.h"

  if (lmp->logfile) fputs(mesg.c_str(), lmp->logfile);

}

/* define this here, so we won't have to include the headers

   everywhere and utils.h will more likely be included anyway. */

std::string utils::getsyserror()

{

  return std::string(strerror(errno));

}

/** \brief try to detect pathname from FILE pointer. Currently only supported on Linux, otherwise will report "(unknown)".

 *

 *  \param buf  storage buffer for pathname. output will be truncated if not large enough

     */

    void logmesg(LAMMPS *lmp, const std::string &mesg);

    /** \brief return a string representing the current system error status

     *

     *  This is a wrapper around calling strerror(errno).

     *

     *  \return  error string

     */

    std::string getsyserror();

    /** \brief safe wrapper around fgets() which aborts on errors

     *  or EOF and prints a suitable error message to help debugging

     *