TypeA
TypeB
TypeA
TypeB
...

my_program -1 streamA -2 streamB

mkfifo streamA streamB

for f in *.ext;

  read #this is just used to test changes when I press enter

  do egrep 'TypeA_Criteria' $f >> streamA
  do egrep 'TypeB_Criteria' $f >> streamB
done

my_prog -1 streamA -2 streamB