pdfTeX version 1.40.0 introduced the primitive
\pdfprimitive which the manual describes as follows.
This command executes the primitive meaning of the following control sequence, if it has been redeﬁned or made undeﬁned. If the following control sequence is undeﬁned and never was a primitive, nothing happens and no error is raised. If the control sequence was initially expandable,
\pdfprimitiveexpands either. Otherwise
(I think “either” should be “too.”)
Is there a way to
\let a control sequence to the primitive version? Something like
The idea being that
\input could be restored to its original meaning (at least locally). Obviously
is not going to work just as
is not going to work.