View source for Mhist

== Description ==
The <span style="color:darkcyan;">''mhist''</span> utility dumps data from the [[History_System|History system]]. You specify which events/tags you're interested in and the time period to query, and the results will be printed to screen.

== Arguments ==
If no arguments are provided, an interactive session will be started that will prompt the user to answer questions about which data should be dumped. The questions are the equivalent of the -e, -v, -h and -t arguments (i.e. show data for the most recent N hours for a single event/variable).

 [-e Event Name] 
 [-v Variable Name]
 [-i Index] index of variables which are arrays
 [-i Index1:Index2] index range of variables which are arrays (max 50)
 [-t Interval] minimum interval in sec. between two displayed records
 [-h Hours] display between some hours ago and now
 [-d Days] display between some days ago and now
 [-f File] specify history file explicitly
 [-s Start date] specify start date YYMMDD[.HHMM[SS]]
 [-p End date] specify end date YYMMDD[.HHMM[SS]]
 [-l] list available events and variables
 [-b] display time stamp in decimal format

== Examples ==
 To enter an interactive session: 
   mhist
 
 To list all existing events and variables: 
   mhist -l
 
 To show data for all variables in event "ExampleEvent" for the last 10 days, with at most one datapoint per minute: 
   mhist -e ExampleEvent -d 10 -t 60
 
 Same as before, but show timestamps as integers (UNIX timestamps) rather than strings like "Mar 30 14:16:14": 
   mhist -e ExampleEvent -d 10 -t 60 -b

== Notes ==
The mhist source code can be found in the Midas package under ../midas/progs.


[[Category:Utilities]] [[Category:History]]