  We search for CP violation in a sample of 20000 Cabibbo-suppressed decays,
$D^+\rightarrow K^+K^0_S\pi^+\pi^-$, and 30000 Cabibbo-favored decays,
$D_s^+\rightarrow K^+K^0_S\pi^+\pi^-$. We use 520 $fb^{-1}$ of data recorded by
the BaBar detector at the PEP-II asymmetric-energy $e^+e^-$ collider operating
at center of mass energies near 10.6 $GeV$. We search for CP violation in the
difference between the $T$-odd asymmetries obtained using triple product
correlations of the $D^+$ ($D_s^+$) and $D^-$ ($D_s^-$) decays, respectively.
The $T$ violation parameter values obtained are $\mathcal{A}_T(D^+) = (-12.0
\pm 10.0_{stat} \pm 4.6_{syst})\times 10^{-3}$ and $\mathcal{A}_T(D_s^+) =
(-13.6 \pm 7.7_{stat} \pm 3.4_{syst}) \times10^{-3}$, which are consistent with
the standard model expectations.
