.functions: Improve getcertnames

Follow-up to 12bb9da.

Many thanks to @dserodio!

.functions

@@ -82,7 +82,7 @@ function gz() {
 # Test if HTTP compression (RFC 2616 + SDCH) is enabled for a given URL.
 # Send a fake UA string for sites that sniff it instead of using the Accept-Encoding header. (Looking at you, ajax.googleapis.com!)
 function httpcompression() {
-	encoding="$(curl -LIs -H 'User-Agent: Mozilla/5 Gecko' -H 'Accept-Encoding: gzip,deflate,compress,sdch' "$1" | grep '^Content-Encoding:')" && echo "$1 is encoded using ${encoding#* }" || echo "$1 is not using any encoding"
+	local encoding="$(curl -LIs -H 'User-Agent: Mozilla/5 Gecko' -H 'Accept-Encoding: gzip,deflate,compress,sdch' "$1" | grep '^Content-Encoding:')" && echo "$1 is encoded using ${encoding#* }" || echo "$1 is not using any encoding"
 }
 
 # Syntax-highlight JSON strings or files
@@ -126,15 +126,15 @@ function getcertnames() {
 		return 1
 	fi
 
-	domain="${1}"
+	local domain="${1}"
 	echo "Testing ${domain}…"
 	echo # newline
 
-	tmp=$(echo -e "GET / HTTP/1.0\nEOT" \
+	local tmp=$(echo -e "GET / HTTP/1.0\nEOT" \
 		| openssl s_client -connect "${domain}:443" 2>&1);
 
 	if [[ "${tmp}" = *"-----BEGIN CERTIFICATE-----"* ]]; then
-		certText=$(echo "${tmp}" \
+		local certText=$(echo "${tmp}" \
 			| openssl x509 -text -certopt "no_header, no_serial, no_version, \
 			no_signame, no_validity, no_issuer, no_pubkey, no_sigdump, no_aux");
 			echo "Common Name:"
@@ -144,7 +144,7 @@ function getcertnames() {
 			echo "Subject Alternative Name(s):"
 			echo # newline
 			echo "${certText}" | grep -A 1 "Subject Alternative Name:" \
-				| head -2 | tail -1 | sed "s/DNS://g" | sed "s/ //g" | tr "," "\n"
+				| sed -e "2s/DNS://g" -e "s/ //g" | tr "," "\n" | tail -n +2
 			return 0
 	else
 		echo "ERROR: Certificate not found.";