is an interpreter that runs the test program given in after load‐
ing  the library.  is not a real interpreter though: it is just a
wrapper around the system‐wide shell defined by executes the  in‐
terpreter,  loads the library and then runs the script.  You must
consider to be a POSIX shell by default and thus should  not  use
any  non‐standard  extensions.   The following options are avail‐
able: Specifies the shell to use instead of the value provided by
Overrides the builtin directory where is located.  Should not  be
overridden  other  than  for  testing  purposes.   Overrides  the
builtin directory where is located.   Should  not  be  overridden
other  than for testing purposes.  Path to the system shell to be
used in the generated scripts.  Scripts must  not  rely  on  this
variable being set to select a specific interpreter.  Scripts us‐
ing  should  start with: #! /usr/bin/env atf‐sh Alternatively, if
you want to explicitly choose a  shell  interpreter,  you  cannot
rely  on to find Instead, you have to hardcode the path to in the
script  and  then   use   the   option   afterwards   as   a   #!
/path/to/bin/atf‐sh ‐s/bin/bash