Shell Programming and Scripting

hello, I would really appreciate any help with this!
i have files in the format ####_*.dat

so like

2913_dsssf_sdfsdf_sddsf.dat
3208889423_lk3mnf_sdfe.dat

what im trying to do is extract the number from the start of the file (end of number will always be followed by _ ) and copy the file to multiple locations, incrementing the # by 1 for each new location

so
2913_dsssf_sdfsdf_sddsf.dat
=
/dir1/2914_dsssf_sdfsdf_sddsf.dat
/dir2/2915_dsssf_sdfsdf_sddsf.dat


3208889423_lk3mnf_sdfe.dat
=
/dir1/3208889424_lk3mnf_sdfe.dat
/dir2/3208889425_lk3mnf_sdfe.dat


huge thanks to anyone who can shed some light on this problem

Code:

for i in *.dat
  do 
   x=${i%%_*}; y=${i#*_}; z=1
  
    for j in directory_list*
     do 
      cp -p $i $j/$(expr $x + $z)"_"$y
      z=$(expr $z + 1)
     done

done

Use echo first, instead of cp to make sure you have the expected output.

about what i have colored on your code post. can you tell me what is it called?
if im correct, is some kind of automated string tokenizer, and i do have some good uses for that :P

Take a look at:How can I use parameter expansion?