ファイル内の重複行を1つにまとめて並び替える

#!/bin/sh
#sortnuiq.sh

. f_askfname.sh
. f_askstring.sh

ask_filename "Target File( Blank is Cancel. ): " 1
if [ $? -ne 0 ]; then
    echo "*** Canceled."
    return 1
fi
FILE1=${_STR}
echo "Target File is \"${FILE1}\""

ask_string "Save File [${FILE1}.uniq]; " 1
if [ $? -ne 0 ]; then
    FILE2="${FILE1}.uniq"
else
    FILE2=${_STR}
fi
echo "Save File is \"${FILE2}\""

#大文字小文字を区別せず重複情報を表示する
sort -f ${FILE1} | uniq -ic > ${FILE2}
echo "*** Successful."
unset FILE1 FILE2 _STR

$ cat 1.txt
aa
bb
cc
dd
ee
aa
aa
aa
bb
bb
cc

$ ./sortuniq.sh 
Target File( Blank is Cancel. ): 1.txt
Target File is "1.txt"
Save File [1.txt.uniq]; 
Save File is "1.txt.uniq"
*** Successful.

$ cat 1.txt.uniq 
      4 aa
      3 bb
      1 cc
      1 cc
      1 dd
      1 ee