Run in series and Parallel

Shell Programming and Scripting
1

I have a list with four dates
say load_date.lst contains

2010-01-01 2010-01-31
2010-03-01 2010-03-31
2010-05-01 2010-05-31
2010-07-01 2010-07-31

And I have directory /lll/src/sql with set of sql's
1_load.sql
2_load.sql
3_load.sql

I want to run the sql'in series with respective to each date and In parallel with respective to load

I mean
1,2,3 with input 2010-01-01 2010-01-31

1,2,3 with input 2010-03-01 2010-03-31

How this can be done?

I have something like this

sql_list=`ls /lll/src/sql/*.sql`

for i in ${sql_list}
do

  c_l=`wc -l load_date.lst | awk ' { print $1 }'`
  nol=`expr $c_l - 0`
  z=1
  while [[ $z -le $nol ]]
  do
  cat load_date.lst | nawk -v I="$z" 'NR==I { print $0 }' | read from_date to_date
  
  echo "$from_date $to_date"
  
       some_script.ksh ${i} ${from_date} ${to_date} &
       
  z=$((z + 1))
  
  done

Will this work? or can you suggest some good ways

Thanks in advance...

2

As in, run 1, 2, 3 in parallel on the same input, but wait for all three to finish before starting another three? If that's all you want that should be doable, but I can't tell what your script's actually doing through all the cat and nawk. I suspect most of the cat | awk | foo | bar | baz | read is unnecessary. Is the input format of your dates different from what you've listed, hence needing conversion in awk? Or are you just reading one line at a time in an odd way?

3

@ Corona688
1,2,3 should run in series and for each date it should run in parallel

4

I'm running out of time to solve this right now but it might help to remember that you can background entire code-blocks. ( while read VAL ; do x ; done < list ) &