use human-readable variable names (issue #1003)

config/action.d/mail-whois-common.conf

@@ -15,9 +15,10 @@ _whois = whois <ip> || echo "missing whois program"
 
 # use heuristics to convert charset of whois output to a target
 # character set before sending it to a mail program
+# make sure you have 'file' and 'iconv' commands installed when opting for that
 _whois_target_charset = UTF-8
 _whois_convert_charset = whois <ip> |
-                         { c=$(cat) ; cs=$(printf %%b "$c" | file -b --mime-encoding -) ; printf %%b "$c" | iconv -f $cs -t %(_whois_target_charset)s//TRANSLIT - ; }
+                         { WHOIS_OUTPUT=$(cat) ; WHOIS_CHARSET=$(printf %%b "$WHOIS_OUTPUT" | file -b --mime-encoding -) ; printf %%b "$WHOIS_OUTPUT" | iconv -f $WHOIS_CHARSET -t %(_whois_target_charset)s//TRANSLIT - ; }
 
 # choose between _whois and _whois_convert_charset in mail-whois-common.local
 # or other *.local which include mail-whois-common.conf.