How to print arguments from a known element until an unknown element of an array with Bash

Question

I am having a blonde moment.

This is my data from myfile.csv

1429829254,e,SE,StckXchg,HDCU3000623,d,scan,253,47968,94,1420824420,JSSE-213,199,BS,KIT,*OUT*
1429897704,e,SE,StckXchg,HDCU3000623,d,scan,253,68496104,103,1420923818,SP-TMX6BP-101-112Z,*OUT*
1429897718,e,SE,StckXchg,HDCU3000623,d,scan,253,68510090,104,1420923832,02132,*OUT*
1429897767,e,SE,StckXchg,HDCU3000623,d,scan,253,68559085,105,1420923878,02132,*OUT*
1429912759,e,SE,StckXchg,HDCU3000623,d,scan,255,47966,107,1420924040,JSF-1,4"MEG0004,*OUT*
1429912766,e,SE,StckXchg,HDCU3000623,d,scan,255,54955,108,1420924047,02134,*OUT*
1429982863,e,SE,StckXchg,HDCU3000623,d,scan,256,47965,120,1420987942,JSDL-JA120901S,*OUT*
1429982870,e,SE,StckXchg,HDCU3000623,d,scan,256,54953,121,1420987961,02132,*OUT*
1429982877,e,SE,StckXchg,HDCU3000623,d,scan,256,61954,109,1420971277,02134,*OUT*

I currently put this data into an array and extract each of the elements individually.

But our input data has changed and now there the elements with a line can vary- and can vary by a lot. I was curious to know how I can extract data from the above sample, from the 12th element up until the last element.

With my code this is what I do:

cat $out_file_name |  while read line
do
    awk_var=`echo "$line" | awk -F"," '{print $1, $5, $10, $12, $13, $14}'`         #Get the appropriate arguments
    awk_var_array=($awk_var)

    timestamp=${awk_var_array[0]}
    container==${awk_var_array[1]}
    scan_id=${awk_var_array[2]}
    part_no=${awk_var_array[3]}
    direction=${awk_var_array[4]}

    #further processing and send the above to a mysql table
done

but now this obviously doesn't work. So I need to find a way of storing all the element from the 12th element till the last element (in/out).

would it be done with a for loop? Something like this perhaps?

for element_count in $(seq 13 $({#awk_var_array[@]}-1))
do
    var_name=my_var_''$element_count
    $var_name=${awk_var_array[element_count]
done

Answer 1

You can use bash parameter expansion ${parameter:offset:length} form with array:

$ array=($(seq 20))
$ printf "%s " "${a[@]: -12}"
9 10 11 12 13 14 15 16 17 18 19 20

Answer 2

Based on the further information we got from the various comments, I think all you need is this code:

while IFS=, read timestamp x x x container x x x x scan_id x part_no direction rest
do
   # compose SQL command using "${timestamp}" "${container}" ... "${direction}" "${rest}" and send it to mysql database
done < "${out_file_name}"

Note: The x in the read command represent dummy fields that will be skipped (and not assigned an own unique identifier), and the variable rest contains all the fields in one variable beyond the ones explicitly enumerated in the read argument list.