-/* Learn from "file" the largest line length (pointed to by "linemax_p") and
- * (pointed to by "n_lines_p" if it is not set to NULL) the number of lines.
+/* Learn from "file" the largest line length (pointed to by "linemax_p"; length
+ * includes newline chars) and (pointed to by "n_lines_p" if it is not set to
+ * NULL) the number of lines (= number of newline chars).
+ *
+ * Returns 0 on success, 1 on error of fseek() (called to return to initial file
+ * reading position).