Initial revision

lang/cem/libcc/gen/seekdir.c

@@ -0,0 +1,37 @@
+#include <sys/types.h>
+#include <sys/dir.h>
+
+/*
+ * seek to an entry in a directory.
+ * Only values returned by "telldir" should be passed to seekdir.
+ */
+seekdir(dirp, loc)
+register DIR *dirp;
+long loc;
+{
+	long curloc, base, offset;
+	extern long telldir();
+	extern struct direct *readdir();
+
+	curloc = telldir(dirp);
+	if (loc == curloc)
+		return;
+	base = loc & ~(DIRBLKSIZ - 1);
+	offset = loc & (DIRBLKSIZ - 1);
+	if (dirp->dd_loc != 0 && offset != 0 &&
+	    (curloc & ~(DIRBLKSIZ-1)) ==  base) {
+		dirp->dd_loc = offset;
+		return;
+	}
+	(void) lseek(dirp->dd_fd, base, 0);
+	dirp->dd_loc = 0;
+	dirp->dd_size = 0;
+	if (offset == 0)
+		(void) readdir(dirp);
+	else {
+		while (dirp->dd_loc < offset) {
+			if (readdir(dirp) == (struct direct *) 0)
+				return;
+		}
+	}
+}