exec/bkgpslog-plan.org

   1 * bkgpslog task list
   2 ** DONE Add job control for short buffer length
   3    CLOSED: [2020-07-02 Thu 16:04]
   4 2020-07-02T14:56Z; bktei> File write operations were bundled into a
   5 magicWriteBuffer function that is called then detached from the script
   6 shell (job control), but the detached job is not tracked by the main
   7 script. A problem may arise if two instances of magicWriteBuffer
   8 attempt to write to the same tar simultaneously. Two instances of
   9 magicWriteBuffer may exist if the buffer length is low (ex: 1 second);
  10 the default buffer length of 60 seconds should reduce the probability
  11 of a collision but it should be possible for the main script to track
  12 the process ID of a magicWriteBuffer() as soon as it detaches and then
  13 checking (via ~$!~ as described [[https://bashitout.com/2013/05/18/Ampersands-on-the-command-line.html][here]]) that the process is still alive.
  14 2020-07-02T15:23Z; bktei> I found that the Bash ~wait~ built-in can be
  15 used to delay processing until a specified job completes. The ~wait~
  16 command will pause script execution until all backgrounded processes
  17 complete.
  18 2020-07-02T16:03Z; bktei> Added ~wait~.
  19 * bkgpslog narrative
  20 ** Initialize environment
  21 *** Init variables
  22 **** Save timeStart (YYYYmmddTHHMMSS±zz)
  23 *** Define Functions
  24 **** Define Debugging functions
  25 **** Define Argument Processing function
  26 **** Define Main function
  27 ** Run Main Function
  28 *** Process Arguments
  29 *** Set output encryption and compression option strings
  30 *** Check that critical apps and dirs are available, displag missing ones.
  31 *** Set lifespans of script and buffer
  32 *** Init temp working dir ~DIR_TMP~
  33 Make temporary dir in tmpfs dir: ~/dev/shm/$(nonce)..bkgpslog/~ (~DIR_TMP~)
  34 *** Initialize ~tar~ archive
  35 **** Write ~bkgpslog~ version to ~$DIR_TMP/VERSION~
  36 **** Create empty ~tar~ archive in ~DIR_OUT~ at ~PATHOUT_TAR~
  37
  38 Set output file name to:
  39 : PATHOUT_TAR="$DIR_OUT/YYYYmmdd..hostname_location.gz.age.tar"
  40 Usage: ~iso8601Period $timeStart $timeEnd~
  41
  42 **** Append ~VERSION~ file to ~PATHOUT_TAR~
  43
  44 Append ~$DIR_TMP/VERSION~ to ~PATHOUT_TAR~ via ~tar --append~
  45
  46 *** Read/Write Loop (Record gps data until script lifespan ends)
  47 **** Determine output file paths
  48 **** Define GPS conversion commands
  49 **** Fill Bash variable buffer from ~gpspipe~
  50 **** Process bufferBash, save secured chunk set to ~DIR_TMP~
  51 **** Append each secured chunk to ~PATHOUT_TAR~
  52 : tar --append --directory=DIR_TMP --file=PATHOUT_TAR $(basename PATHOUT_{NMEA,GPX,KML} )
  53 **** Remove secured chunk from ~DIR_TMP~