AstroNote 2020-1

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DRAFT
2020-01-01 15:15:49
Type: Announcement-Tool/Utility
A bash shell utility to query and download classified SNe from TNS
Authors: S. R. Kulkarni
Abstract:
QueryTNS_SN is a stand alone utility, written in bash, which can query TNS for classified supernovae (SNe) in a given month of a year, a range of moths in a given year or all 12 months of a given year and return a file for each month. The files contain a line per classified SN.

#!/bin/bash
# queries TNS and writes file of classified SN per month in TSV format
#
#-----------------------------------------------------------------------
# usage: QueryTNS_SN  year [month_start [month_end]]
#-----------------------------------------------------------------------
#
# Examples:
#   QueryTNS_SN 2018      (Jan thru Dec of 2018)
#   QueryTNS_SN2018 2 3  (February & March 2018)
#   QueryTNS_SN 2018 6    (only June 2018)
#   Output: SN_YYYY_MM.tsv e.g. SN_2018_6.tsv for above example
#
#   Warning: issued if more SN found than internal TNS buffer size
#
# Obscure Usage: if year is negative then header line is included
#   QueryTNS_SN -2018 2 3
#
# Weaknesses:
#  no error checking for valid years or months
#  all months have 31 days! (apparently TNS does not mind this)
#
# 30 December 2019 (SRK)
#-----------------------------------------------------------------------


MAX=500     #TNS, as of 2019, set a limit of 500 records


#-----------------------------------------------------------------------
get1month () {
#-----------------------------------------------------------------------
#
#usage: get1month(YYYY,M) where YYYY is year & M=[1-12] is month number
#       output file SN_YYYY_MM.tsv (with one line er SN from TNS)
#       if YYYY<0 then header is included in the output.

    Year=$1; Month=$2;

    #build output file name
       sgn=1;
       [ $1 -lt 0 ] && { Year=${Year:1}; sgn=-1; }
       Outfile="SN_"$Year"_"$(printf "%02d" $2)".tsv"      

    #compose start and end date for search
       start_date=$Year"-"$Month"-"01             
       end_date=$Year"-"$Month"-"31         


#---------------forming string for inquiry with TNS--------------------
    Head="https://wis-tns.weizmann.ac.il/search?&classified_sne=1"

    Date="&date_start%5Bdate%5D="   
    Date+=$start_date
    Date+="&date_end%5Bdate%5D="    
    Date+=$end_date

    Tail="&num_page="
    Tail+=$MAX            #MAX is maximum buffer size, set by TNS
    Tail+="&format=tsv"      

    cmd=$Head$Date$Tail       #html inquiry now fully formed

#----------------launch call to TNS-------------------------------------

   echo -n "Date range: " $start_date to  $end_date ".."
      if [ $sgn = 1 ]; then
          curl -s  "$cmd" | sed '1d' > $Outfile
            nSN=$(wc -l < $Outfile)
      else
          curl -s  "$cmd" | sed -n 'p' >  $Outfile
          nSN=$(grep -c "" $Outfile)
          nSN=$((nSN-1))                 #do not count header line
      fi
    echo " outfile:" $Outfile " $nSN (SNe)"

#---------------------Check buffer size---------------------------------
    [ $nSN -eq $MAX ] && echo "Warning; internal buffer size insufficient"

    return $?
}
#-----------------------------------------------------------------------
#    Main program

#---------------check input parameters, determine months ----------------

    #check if input parameters are sufficient

      [ $# = 0 ] && { echo "no year"; exit -1; }


    #determine the range of months

      [ $# = 1 ] && { mstart=1; mend=12; }
      [ $# = 2 ] && { mstart=$2; mend=$2; }
      [ $# = 3 ] && { mstart=$2; mend=$3; }


    for ((Month = mstart; Month <= mend; Month += 1)); do
      get1month $1 $Month
    done