load file to clob using loadfromfile(oracle8.1.7),but the length of file and clob is not equal

[wqhdebian]

fils:=bfilename (directory =receiveDir,fil ename =fileName);
dbms_lob.open(f ils,dbms_lob.fi le_readonly);
dbms_lob.create temporary(xDoc, true);
---------------- the result is 353
dbms_output.put _line(dbms_lob. getlength(fils) );
dbms_lob.loadfr omfile(xDoc,fil s,dbms_lob.getl ength(fils));
-------------- the result is 176
dbms_output.put _line(dbms_lob. getlength(xdoc) );
dbms_lob.close( file_loc =fils);
commit;

I just want to test if I can load a text file into database with
content unchanegd,but the answer from this fact is not.How I can load
a txt file (xml file) into database without changing the content.