slowhttptest(1) on Linux
The text 38751d26bd81, as Debian 8 (Jessie) shipped it.
Denial Of Service attacks simulator
Flags it lists
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-B -
-H -
-R -
-X -
-a -
-b -
-g -
-i -
-l -
-n -
-p -
-s -
-u -
-v -
-w -
-x -
-y -
-z