$ ls       
abc1216    abc124     abckwefn   xyz116     xyz125     xyzwefwef
abc123     abc125     demo       xyz124     xyz129
$ cat demo 
#!/bin/sh
echo "\n\nSimple if\n"
for file in abc* ghi* xyz*
do
   testval="${file%${file##???}}"  
   if [ "$testval" = "abc" ];
   then
      echo "Found abc file $file"
   fi
   if [ "$testval" = "ghi" ];
   then
      echo "Found ghi file $file"
   fi
   if [ "$testval" = "xyz" ];
   then
      echo "Found xyz file $file"
   fi
done

echo "\n\nUsing a CASE statement\n"
for file in abc* ghi* xyz*
do
   testval="${file%${file##???}}"
   case "$testval" in
     abc) echo "Found abc file $file"   ;;
     ghi) echo "Found ghi file $file"   ;;
     xyz) echo "Found xyz file $file"   ;;
     *)   echo "Found other file $file" ;;
   esac
done

$ demo     


Simple if

Found abc file abc1216
Found abc file abc123
Found abc file abc124
Found abc file abc125
Found abc file abckwefn
Found xyz file xyz116
Found xyz file xyz124
Found xyz file xyz125
Found xyz file xyz129
Found xyz file xyzwefwef


Using a CASE statement

Found abc file abc1216
Found abc file abc123
Found abc file abc124
Found abc file abc125
Found abc file abckwefn
Found other file ghi*
Found xyz file xyz116
Found xyz file xyz124
Found xyz file xyz125
Found xyz file xyz129
Found xyz file xyzwefwef
$