Compute useful floating point time and time difference from a PAS image name. Later I found that it is very inefficent to run something line pasnname.sh on a list of images inside a script. The (much) better way is to run this code on an input list of image. Hence, i developed pasnames.sh.

pasname.sh --help 

Usage: pasname.sh /hetdata/data/20160930/acm/20160930T111309.0_acm_sci 79577.1 
arg1 - FITS file (can be full path) 
arg2 - previous time in seconds (0.0)  
% pasname.sh /home/sco/HET_work/gc_data_Sep2018/20180910/gc1/20180910T224720.2_gc1_sci.fits 0.0 
      82040.2       82040.2

Usage: pasnames.sh list.1 79577.1 
arg1 - file listing fullpath PAS FITS file names 
arg2 - previous time in seconds (0.0)  

Holy shit! Thanks to some discussion with Fim Fowler, I decided to rewirue paname.sh to a code that handles an input list (pasnames.sh).

% wc -l list.IMAGES
7484 list.IMAGES

*** Running as a script: 
% pas_timelist list.IMAGES list.out N
a 1  Fri Sep 28 17:36:42 UTC 2018
a 2  Fri Sep 28 17:37:11 UTC 2018
29.000000   (aprroximate run time in seconds)       *** Takes 29 second to run 

*** Running as a program that processes a list: 
% pasnames.sh list.IMAGES 0.0                       *** Takes less than 1 second to run