tmac Time machine to prevent any attempt to go back to the past. It will block all data records from going to the output stream for which the time stamp is not greater than or equal to the time stamp of the last record sent on the output stream. Time stamp of the first selected data record defines the "present" (first record after skipping the specified time in "skip" keyword). Hence the first selected data record is always put on the output stream. The above filtering operation can be performed on selected scans, which will then produce a LTA file with only the selected scans in it. Author Sanjay Bhatnagar (sanjay@ncra.tifr.res.in) in (default ==> Input from stdin) The input LTA format file name (of course!). out (default ==> Output to stdout) The output file name (of course!). skip (default ==> As defined in $GCONF/tmac.config. This is 1m currently) The length of time (in your rest frame in units of seconds) for which the input data is not put on the output stream. scans (default==> All scans) The list of selected scan numbers. The output file will contain only the selected scans.