--- /dev/null
+%
+% (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}