eval: Add s flag, use p_fs by default, error out on unknown flag

1 files changed, 5 insertions, 4 deletions

diff --git a/runtime/doc/eval.txt b/runtime/doc/eval.txt
index 727199f742..7060cc4186 100644
--- a/runtime/doc/eval.txt
+++ b/runtime/doc/eval.txt
@@ -7916,10 +7916,11 @@ writefile({list}, {fname} [, {flags}])
 			:call writefile(["foo"], "event.log", "a")
 			:call writefile(["bar"], "event.log", "a")
 <
-		When {flags} contains "S" fsync() call is not used. This means 
-		that writefile() will finish faster, but writes may be left in 
-		OS buffers and not yet written to disk. Such changes will 
-		disappear if system crashes before OS does writing.
+		When {flags} contains "S" fsync() call is not used, with "s" 
+		it is used, 'fsync' option applies by default. No fsync() 
+		means that writefile() will finish faster, but writes may be 
+		left in OS buffers and not yet written to disk. Such changes 
+		will disappear if system crashes before OS does writing.
 
 		All NL characters are replaced with a NUL character.
 		Inserting CR characters needs to be done before passing {list}