%
% (c) The GRASP/AQUA Project, Glasgow University, 1994
%
\subsection[fileSize.lc]{hfileSize Runtime Support}

\begin{code}

#include "rtsdefs.h"
#include "stgio.h"

#ifdef HAVE_SYS_TYPES_H
#include <sys/types.h>
#endif

#ifdef HAVE_SYS_STAT_H
#include <sys/stat.h>
#endif
  
StgInt
fileSize(fp, result)
StgForeignObj fp;
StgByteArray result;
{
    struct stat sb;

    while (fstat(fileno((FILE *) fp), &sb) < 0) {
	/* highly unlikely */
	if (errno != EINTR) {
	    cvtErrno();
	    stdErrno();
	    return -1;
	}
    }
    if (S_ISREG(sb.st_mode)) {
	/* result will be word aligned */
	*(off_t *) result = sb.st_size;
	return 0;
    } else {
	ghc_errtype = ERR_INAPPROPRIATETYPE;
	ghc_errstr = "not a regular file";
	return -1;
    }
}

\end{code}