SQL> ed
Wrote file afiedt.buf

  1* select line,text from user_source where name='WRITE_LOG'
SQL> /

      LINE TEXT
---------- ------------------------------------------------------------
         1 PROCEDURE write_log
         2 (fname IN varchar2,
         3 message IN varchar2,
         4 mo IN varchar2)
         5 is
         6 log_file  UTL_FILE.FILE_TYPE;         -- file handle for the
            log file

         7 begin
         8 log_file := UTL_FILE.FOPEN('/rman/logs',fname,mo);
         9 UTL_FILE.PUTF(log_file,'%sn',message);
        10 UTL_FILE.FCLOSE(log_file);
        11 EXCEPTION
        12         WHEN NO_DATA_FOUND THEN
        13              DBMS_OUTPUT.PUT_LINE('no_data_found');
        14      WHEN UTL_FILE.INVALID_PATH THEN
        15              DBMS_OUTPUT.PUT_LINE('UTL_FILE.INVALID_PATH');
        16      WHEN UTL_FILE.WRITE_ERROR THEN
        17                 DBMS_OUTPUT.PUT_LINE('UTL_FILE.WRITE_ERROR')
           ;

        18              WHEN OTHERS THEN
        19                 DBMS_OUTPUT.PUT_LINE('other stuff');
        20 end;

20 rows selected.