-bytes in size. If the file previously
-was larger than this size, the extra data
-is lost. If the file was smaller than this size, it will be extended as
-if by writing bytes with the value zero.
-With
-.Fn ftruncate ,
-the file must be open for writing.
+bytes in size. If the file size exceeds
+.Fa length ,
+any extra data is discarded. If the file size is smaller than
+.Fa length ,
+the file is extended and filled with zeros to the indicated length.
+The
+.Fn ftruncate
+form requires the file to be open for writing.
+.Pp
+Note:
+.Fn ftruncate
+and
+.Fn truncate
+do not modify the current file offset for any open file descriptions associated with the file.