Enhance `remove` to accept an IP and hostname pair.

This provides a mechanism for removing exact IP and hostname pairs.
The existing search string functionality should continue to function as
it did previously.

hosts

@@ -922,27 +922,56 @@ list() {
 desc "remove" <<EOM
 Usage:
   $_ME remove ( <ip> | <hostname> | <search string> ) [--force]
+  $_ME remove <ip> <hostname>
 
 Options:
   --force  Skip the confirmation prompt.
 
 Description:
   Remove one or more records based on a given IP address, hostname, or search
-  string.
+  string. If an IP and hostname are both provided, only records matching the
+  IP and hostname pair will be removed.
 EOM
 remove() {
   _verify_write_permissions
-  local search_string=${1:-}
-  if [[ -z $search_string ]]
+  local is_search_pair=0
+  local search_ip
+  local search_hostname
+  local search_string
+
+  _debug printf "remove() \$1: %s\n" "${1:-}"
+  _debug printf "remove() \$2: %s\n" "${2:-}"
+
+  if [[ -z "${1:-}" ]]
   then
     $_ME help remove
     exit 1
+  elif [[ -n "${2:-}" ]] && [[ ! "${2}" =~ ^-\* ]]
+  then
+    search_ip="${1}"
+    search_hostname="${2}"
+    is_search_pair=1
+    _debug printf "remove() \$is_search_pair: %s\n" "$is_search_pair"
   else
+    search_string=${1:-}
+    _debug printf "remove() \$search_string: %s\n" "$search_string"
+  fi
+
   # Regular Expression Notes
   #
   # - Note double periods in regular expression in order to emulate /.+/,
   #   which apparently doesn't work properly with all versions of sed.
   local target_records
+
+  if ((is_search_pair))
+  then
+    target_records=$(
+      sed -n \
+        -e "s/^\(${search_ip}[${_TAB_SPACE_}]*${search_hostname}[${_TAB_SPACE_}]..*\)$/\1/p" \
+        -e "s/^\(${search_ip}[${_TAB_SPACE_}]*${search_hostname}\)$/\1/p" \
+        "${HOSTS_PATH}"
+    )
+  else
     target_records=$(
       sed -n \
         -e "s/^\(${search_string}[${_TAB_SPACE_}]..*\)$/\1/p" \
@@ -950,6 +979,7 @@ remove() {
         -e "s/^\(..*[${_TAB_SPACE_}]${search_string}\)$/\1/p" \
         "${HOSTS_PATH}"
     )
+  fi
 
   if [[ -z ${target_records:-} ]]
   then
@@ -983,13 +1013,20 @@ remove() {
   #
   # - Note double periods in regular expression in order to emulate /.+/,
   #   which apparently doesn't work properly with all versions of sed.
+  if ((is_search_pair))
+  then
+    sed -i '' \
+      -e "s/^${search_ip}[${_TAB_SPACE_}]${search_hostname}[${_TAB_SPACE_}]..*$/d" \
+      -e "s/^${search_ip}[${_TAB_SPACE_}]${search_hostname}$/d" \
+      "${HOSTS_PATH}"
+  else
     sed -i '' \
       -e "/^${search_string}[${_TAB_SPACE_}]..*$/d" \
       -e "/^..*[${_TAB_SPACE_}]${search_string}[${_TAB_SPACE_}]..*$/d" \
       -e "/^..*[${_TAB_SPACE_}]${search_string}$/d" \
       "${HOSTS_PATH}"
-    printf "Removed:\n%s\n" "${target_records}"
   fi
+  printf "Removed:\n%s\n" "${target_records}"
 }
 
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