syslog-ng: add logread wrapper

Many (LuCI) packages require logread. Otherwise, for example, System Log tab in LuCI is empty

Signed-off-by: Dirk Brenken <dev@brenken.org>

admin/syslog-ng/Makefile

@@ -82,6 +82,8 @@ define Package/syslog-ng/install
 	$(INSTALL_DIR) $(1)/etc/syslog-ng.d
 	$(INSTALL_DATA) ./files/syslog-ng.conf $(1)/etc
 	touch $(1)/etc/syslog-ng.d/.keep
+
+	$(INSTALL_BIN) ./files/logread $(1)/usr/sbin
 endef
 
 define Package/syslog-ng/postinst

admin/syslog-ng/files/logread

@@ -0,0 +1,76 @@
+#!/bin/sh
+# Shell script compatibility wrapper for /sbin/logread
+#
+# Copyright (C) 2019 Dirk Brenken <dev@brenken.org>
+#
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; either version 2 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+# General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program; if not, write to the Free Software
+# Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+#
+
+logfile="/var/log/messages"
+
+if [ ! -f "${logfile}" ]
+then
+	printf "%s\n" "Error: logfile not found!"
+	exit 2
+fi
+
+usage()
+{
+	printf "%s\n" "Usage: logread [options]"
+	printf "%s\n" "Options:"
+	printf "%5s %-10s%s\n" "-l" "<count>" "Got only the last 'count' messages"
+	printf "%5s %-10s%s\n" "-e" "<pattern>" "Filter messages with a regexp"
+	printf "%5s %-10s%s\n" "-f" "" "Follow log messages"
+	printf "%5s %-10s%s\n" "-h" "" "Print this help message"
+}
+
+if [ -z "${1}" ]
+then
+	cat "${logfile}"
+	exit 0
+else
+	while [ "${1}" ]
+	do
+		case "${1}" in
+			-l)
+				shift
+				count="${1//[^0-9]/}"
+				tail -n "${count:-50}" "${logfile}"
+				exit 0
+				;;
+			-e)
+				shift
+				pattern="${1}"
+				grep -E "${pattern}" "${logfile}"
+				exit 0
+				;;
+			-f)
+				tail -f "${logfile}"
+				exit 0
+				;;
+			-fe)
+				shift
+				pattern="${1}"
+				tail -f "${logfile}" | grep -E "${pattern}"
+				exit 0
+				;;
+			-h|*)
+				usage
+				exit 1
+				;;
+		esac
+		shift
+	done
+fi