diff --git a/main.sh b/main.sh
index 070e023..0837a4e 100755
--- a/main.sh
+++ b/main.sh
@@ -3,27 +3,55 @@
 IFS=$'\n'
 set -eu -o pipefail
 
+
 cleanup () {
   echo
+
+  # if Unbound is not started, exit from function
+  [ -v unbound_pid ] || return
+
   echo '==> Stopping Unbound'
-  [ -v unbound_pid ] && kill -INT "$unbound_pid"
+  kill -INT "$unbound_pid"
   echo
 }
 
 trap cleanup EXIT
 
+
+built_or_system () {
+  # args: [1]custom/build/path [2]program_name [3]build_script [4]package_name
+
+  if [ -e "$1" ]; then
+    echo "$2: using custom build at $1" >&2 # stderr; just a message to user
+    echo "$1" # stdout; captured into a variable with $(), see below
+
+  elif exe=$(which "$2"); then
+    echo "$exe" # stdout
+
+  else
+    echo " ** $2: not found neither built nor in-system" >&2 # stderr
+    echo "    use script './$3' to automatically build it at the correct path" >&2
+
+    # if $4 is set, say about possible pkg name
+    [ -v 4 ] && \
+    echo "    or install it from your package manager, usually pkg is named '$4'" >&2
+
+    return 1
+  fi
+}
+
+exe_dig="bind9/bin/dig/dig"
+exe_drill="ldns/drill/drill"
+exe_hr="hickory-dns/target/release/resolve"
+
 echo
 echo '==> Checking deps'
-echo 'Note: dig is installed from package usually named "bind-utils"'
-echo '      drill -- package "ldns"'
-echo "      and hickory's resolve can be built with ./build_hr.sh"
-echo '      (this script will find it in subdir, no need to install)'
 which unbound
 which hyperfine
-which dig
-which drill
-hr="hickory-dns/target/release/resolve"
-[ -e "$hr" ] || hr=$(which resolve)
+exe_dig=$(built_or_system "$exe_dig" dig "build_dig.sh" bind-utils)
+exe_drill=$(built_or_system "$exe_drill" drill "build_drill.sh" ldns)
+exe_hr=$(built_or_system "$exe_hr" resolve "build_hr.sh")
+
 
 echo
 echo '==> Starting Unbound'
@@ -31,30 +59,35 @@ unbound -c ./unbound.conf -dp 2>unbound.log &
 unbound_pid=$!
 sleep 2
 
+
 echo
 echo '==> Benchmarks for A domain.tld.'
 hyperfine -N \
-  "dig -p 2253 domain.tld @127.0.0.1" \
-  "drill -p 2253 domain.tld @127.0.0.1" \
-  "$hr -n 127.0.0.1:2253 domain.tld"
+  "$exe_dig -p 2253 domain.tld @127.0.0.1" \
+  "$exe_drill -p 2253 domain.tld @127.0.0.1" \
+  "$exe_hr -n 127.0.0.1:2253 domain.tld"
 
 echo
 echo '==> Benchmarks for AAAA domain.tld.'
 hyperfine -N \
-  "dig -p 2253 aaaa domain.tld @127.0.0.1" \
-  "drill -p 2253 aaaa domain.tld @127.0.0.1" \
-  "$hr -n 127.0.0.1:2253 -t AAAA domain.tld"
+  "$exe_dig -p 2253 aaaa domain.tld @127.0.0.1" \
+  "$exe_drill -p 2253 aaaa domain.tld @127.0.0.1" \
+  "$exe_hr -n 127.0.0.1:2253 -t AAAA domain.tld"
 
 echo
 echo '==> Benchmarks for MX domain.tld.'
 hyperfine -N \
-  "dig -p 2253 mx domain.tld @127.0.0.1" \
-  "drill -p 2253 mx domain.tld @127.0.0.1" \
-  "$hr -n 127.0.0.1:2253 -t MX domain.tld"
+  "$exe_dig -p 2253 mx domain.tld @127.0.0.1" \
+  "$exe_drill -p 2253 mx domain.tld @127.0.0.1" \
+  "$exe_hr -n 127.0.0.1:2253 -t MX domain.tld"
 
 echo
 echo '==> Benchmarks for CNAME mail.domain.tld.'
 hyperfine -N \
-  "dig -p 2253 mail.domain.tld @127.0.0.1" \
-  "drill -p 2253 mail.domain.tld @127.0.0.1" \
-  "$hr -n 127.0.0.1:2253 mail.domain.tld"
+  "$exe_dig -p 2253 mail.domain.tld @127.0.0.1" \
+  "$exe_drill -p 2253 mail.domain.tld @127.0.0.1" \
+  "$exe_hr -n 127.0.0.1:2253 mail.domain.tld"
+
+
+echo
+echo '==> All done'