Shell Programming and Scripting

somename1_1.xy
somename1_2.xy
somename2_1.xy
somename2_2.xy
..........
.........

for file in *
do
   mkdir somenameN  
   do_something_with  file_1.xy  file_2.xy > ./somenameN/somenameN_out
done

for file in *1.xy
do
  if [ -f "$file" ]; then
    echo "$file ${file%1.xy}2.xy"
  fi
done

for file in somename*_1.xy ; do echo ${file} ; done

for file in somename*_1.xy
do
 echo ${file}
...insert whatever magic....
done

for file in $(ls | sed 's/_[12].xy//' file | uniq)
  do mkdir "$file"N
     do_something_with  "$file"_1.xy  "$file"_2.xy > ./"$file"N/"$file"N_out
  done

while read filename1 && read filename2
do
...
done < inputfile