cleanup, docs

site/doc/pages/file_exists.txt

@@ -2,14 +2,18 @@
 bool file_exists(String path)
 
 :params
-path : the path name to be checked
-return value : true if the file exists
+path : path to check, resolved against the unit's directory
+return value : true if a regular file exists at `path`
+
+:content
+Reports whether a regular file exists. Use it to guard reads or to confirm a write or delete took effect. It is file-oriented and returns false for directories — use `file_stat()` and check `is_dir` to test for a directory.
+
+:example
+file_put_contents("/tmp/doc-exists.txt", "x");
+print(file_exists("/tmp/doc-exists.txt") ? "exists" : "missing", " / ");
+print(file_exists("/tmp/doc-not-here-xyz.txt") ? "exists" : "missing", "\n");
 
 :see
 >sys
-
-:content
-Checks whether the file or path specified by `path` exists.
-
-:example
-print("file_exists example\n");
+file_stat
+file_unlink