Merge pull request #750 from shtrom/file_length_

[file_length_] A versatile plugin to count the lines in specified files

plugins/system/file_length_

@@ -0,0 +1,74 @@
+#!/bin/sh
+
+: << =cut
+
+=head1 NAME
+
+file_length_ - Plugin to monitor the length of specified files
+
+Useful for things such as lists (white, black, user, ...).
+
+=head1 CONFIGURATION
+
+    [file_length_IDENTIFIER]
+    env.files FILEPATHGLOB1 FILEPATHGLOB2 ...
+    env.category DEFAULTS_TO_system
+    env.title OPTIONAL_TITLE
+    env.logarithmic 1
+
+=head1 AUTHOR
+
+Olivier Mehani <shtrom+munin@ssji.net> (based on disk/log_sizes)
+
+=head1 LICENSE
+
+GPLv2
+
+=head1 MAGIC MARKERS
+
+  #%# family=manual
+
+=cut
+
+# needs shellcheck -x /usr/share/munin/plugins/plugin.sh
+# shellcheck source=/usr/share/munin/plugins/plugin.sh
+. "$MUNIN_LIBDIR/plugins/plugin.sh"
+
+NAME=$(echo "$0" | sed 's/.*_//')
+TITLE=${title:-File lengths for $NAME}
+CATEGORY=${category:-system}
+
+FILES=${files:-/var/log/messages}
+# we want globbing to happen here
+# shellcheck disable=SC2116 disable=SC2086
+FILES=$(echo $FILES)
+
+
+if [ "$1" = "config" ] ; then
+	# shellcheck disable=SC2154
+	if [ "${logarithmic}" = "1" ]; then
+		graph_args="-o"
+	else
+		graph_args="-l 0"
+	fi
+	cat <<EOF
+graph_title ${TITLE}
+graph_args ${graph_args} --base 1000
+graph_category ${CATEGORY}
+graph_info This graph shows the length of ${FILES}
+graph_vlabel length (lines)
+EOF
+
+	for F in $FILES; do
+		MF=$(clean_fieldname "$F")
+		BF=$(basename "$F")
+		echo "$MF.label ${BF}"
+	done
+
+else
+	for F in $FILES; do
+		MF=$(echo "$F" | sed 's/[-\/\.]/_/g')
+		echo "$MF.value $(wc -l < "$F")"
+		echo "$MF.extinfo $(stat --printf="%sB\n" "$F")"
+	done
+fi