do not print an error message when a program can't be found

@@ -6,19 +6,20 @@
 # I also assume through all scripts that eval is available.
 #
 [ -z "${WHICH}" ]    && WHICH="/usr/bin/which"
-[ -z "${UNAME}" ]    && UNAME="$(${WHICH} uname)"
-[ -z "${GREP}" ]     && GREP="$(${WHICH} grep)"
-[ -z "${AWK}" ]      && AWK="$(${WHICH} awk)"
-[ -z "${SED}" ]      && SED="$(${WHICH} sed)"
-[ -z "${ECHO}" ]     && ECHO="$(${WHICH} echo)"
-[ -z "${SORT}" ]     && SORT="$(${WHICH} sort)"
-[ -z "${TR}" ]       && TR="$(${WHICH} tr)"
-[ -z "${PRINTF}" ]   && PRINTF="$(${WHICH} printf)"
-[ -z "${LOGGER}" ]   && LOGGER="$(${WHICH} logger)"
-[ -z "${NPROC}" ]    && NPROC="$(${WHICH} nproc)"
-[ -z "${LSCPU}" ]    && LSCPU="$(${WHICH} lscpu)"
-[ -z "${IP}" ]       && IP="$(${WHICH} ip)"
-[ -z "${IFCONFIG}" ] && IFCONFIG="$(${WHICH} ifconfig)"
+[ -z "${UNAME}" ]    && UNAME="$(${WHICH} uname 2>/dev/null)"
+[ -z "${GREP}" ]     && GREP="$(${WHICH} grep 2>/dev/null)"
+[ -z "${AWK}" ]      && AWK="$(${WHICH} awk 2>/dev/null)"
+[ -z "${SED}" ]      && SED="$(${WHICH} sed 2>/dev/null)"
+[ -z "${ECHO}" ]     && ECHO="$(${WHICH} echo 2>/dev/null)"
+[ -z "${SORT}" ]     && SORT="$(${WHICH} sort 2>/dev/null)"
+[ -z "${TR}" ]       && TR="$(${WHICH} tr 2>/dev/null)"
+[ -z "${PRINTF}" ]   && PRINTF="$(${WHICH} printf 2>/dev/null)"
+[ -z "${LOGGER}" ]   && LOGGER="$(${WHICH} logger 2>/dev/null)"
+[ -z "${NPROC}" ]    && NPROC="$(${WHICH} nproc 2>/dev/null)"
+[ -z "${LSCPU}" ]    && LSCPU="$(${WHICH} lscpu 2>/dev/null)"
+[ -z "${SYSCTL}" ]   && SYSCTL="$(${WHICH} sysctl 2>/dev/null)"
+[ -z "${IP}" ]       && IP="$(${WHICH} ip 2>/dev/null)"
+[ -z "${IFCONFIG}" ] && IFCONFIG="$(${WHICH} ifconfig 2>/dev/null)"
 
 export WHICH UNAME GREP AWK SED ECHO SORT TR PRINTF LOGGER NPROC LSCPU IP IFCONFIG