With hangul .txt file;

1. get rid of within-file file IDs;
cat 302000.txt | sed 's/[0-9].*\.txt\#\#//g' > tmp1

2. delete blank lines;
cat tmp1 | tr -s '\012' '\012' > tmp1

3. delete the first blank line;
cat tmp1 | wc                
     46     968    6849
cat tmp1 | tail -45 > tmp2 
cat 302000.tx3 | wc
     45     968    6848

4. split the file;
 split -l 1 tmp2 302000--


Replace 4 with the following;

csplit -zsk -f 302000- tmp2 1 {*}

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With 302000-prep3.txt, I didn't use -z option, and it gave me an additional initial blank line. That way, -00 doesn't contain any, and -01 corresponds to 01 file in .fid file

csplit -sk -f 302000- tmp2 1 {*}