--help updates

nlog

@@ -40,17 +40,16 @@ print_help() {
   echo "	--to <to time>, default=now"
   echo "	--notime don't convert timestamp to human time"
   echo "	-c|--constant) the equivalent of a tail -f on the Nagios log file"
-  echo "All input is evaluated as a regexp for pattern matching."
+  echo "	--file <file[s]>) scan <file[s]> instead of $file; use \"...\" if wildcards"
+  echo ""
+  echo "All input is evaluated as a case-insensitive regexp surrounded by wildcards."
   echo "Time values can be in the following formats:"
-  echo "	HH:MM[:SS]	MM/DD/YYYY	MM/DD/YYYY HH:MM[:SS]	-2 (ie, two days ago)"
+  echo "	HH:MM[:SS]	YYYY-MM-DD	YYYY-MM-DD HH:MM[:SS]*"
-  echo "So to see yesterday's critical service alerts, try this:"
+  echo "This program does not directly scan log files other than the current one.  If you want"
-  echo "	$0 [-A SERVICE] [-a ALERT] -f 00:00 -t 23:59 -y 1"
+  echo "to scan older files, use the --file option.  Note that this can be combined with the"
-  echo "The logic for scanning which files to search relies upon Nagios rotating log"
+  echo "--from and --to options, but keep in mind that file names are named based on the date they"
-  echo "files once per day, at midnight.  This causes a \"LOGFILE ROTATE\" message to"
+  echo "were rotated, not the date of their contents."
-  echo "occur in the logfile, which this program uses to determine if the logfile could"
+  echo "*Due to the awk pattern matching, dates before 2020-09-09 will produce empty output."
-  echo "contain valid information for the date range specified on the command line."
-  echo "While this dramatically speeds up file processing time, it could lead to skipped"
-  echo "data if the Nagios logfile rotation schedule is ever changed."
   exit;
 }