Define a control file

lang=java
(
  ${Column name} ${Byte offset} (optional) "${Preprocessing function}",
  ${Column name} ${Byte offset} (optional) "${Preprocessing function}",
  ${Column name} ${Byte offset} (optional) "${Preprocessing function}"
);

lang=java
(
  c1 "lower(c1)",                                                                                 -- Convert the characters in the c1 column to lowercase.
  c2 "ltrim(c2)",                                                                                 -- Truncate leading spaces from the values in the c2 column.
  c3 "rtrim(c3)",                                                                                 -- Truncate trailing spaces from the values in the c3 column.
  c4 "substr(c4,0,5)",                                                                            -- Extract a string of 5 characters from the first position in the values of the c4 column.
  c5 "trim(c5)",                                                                                  -- Truncate leading and trailing spaces from the values in the c5 column.
  c6 "upper(c6)",                                                                                 -- Convert the characters in the c6 column to uppercase.
  c7 "nanvl(c7,'0')",                                                                             -- Verify if the values in the c7 column are numeric. If not, return 0.
  c8 "replace(c8,'a','A')",                                                                       -- Replace 'a' with 'A' in the values of the c8 column.
  c9 "nvl(c9,'nill')",                                                                            -- Check if the values in the c9 column are null. If so, return the string 'nill'.
  c10 "to_timestamp(c10,'yyyyMMddHHmmssSSS')",                                                    -- Format the values in the c10 column. If the formatting fails, return null. Otherwise, return a timestamp in the format of yyyy-MM-dd HH:mm:ss.SSS.
  c11 "length(c11)",                                                                              -- Calculate the length of the values in the c11 column.
  c12 "lpad(c12,5,'x')",                                                                          -- Add a 5-character string 'x' to the left of the values in column c12
  c13 "rpad(c13,5,'x')",                                                                 -- Add a 5-character string 'x' to the right of the values in column c13
  c14 "convert(c14,'utf-8','gbk')",                                                               -- Convert the character encoding of the values in the c14 column from gbk to utf-8.
  c15 "concat(c15, '_suffix')",                                                                   -- Concatenate the values in the c15 column with the constant '_suffix'.
  c16 "none",                                                                                     -- Return the values in the c16 column without any processing.
  c17 "systimestamp",                                                                             -- Return the current timestamp of the cluster for the values in the c17 column.
  c18 "constant('1')",                                                                            -- Return the constant value 1 for the values in the c18 column.
  c19 "tmsfmt(c19,'yyyyMMddHHmmssSSS','20210310000000000','yyyyMMddHHmmssSSS')",                  -- Verify the date in the values of the c19 column. If the verification fails, return the default value.
  c20 "lpadb(c20,5,'x')",                                                                      -- Add five single-byte 'x' characters to the left side of the values in the c20 column.
  c21 "rpadb(c21,5,'x')",                                                                 -- Add five single-byte 'x' characters to the right side of the values in the c21 column.
  c22 "case when length(trim(c22))<18 then 'Y' else 'N' end",                                     -- Check if the length of the values in the c22 column (after trimming) is less than 18. If so, return 'Y'; otherwise, return 'N'.
  c23 "case length(trim(c23)) when '1' then 'one' when '2' then 'two' else 'unknown' end",        -- Check if the values in the c23 column (after trimming) are equal to '1' or '2'. If so, return the corresponding value; otherwise, return 'unknown'.
  c24 "sysdate",                                                                                  -- Return the current date for the values in the c24 column.
  c25 "sequence(100,1)"                                                                           -- Generate an incremental sequence value for the c25 column. The initial value is 100 and the increment is 1.
  c26 "reverse(c26)",                                                                             -- Reverse the values in the c26 column.
  c27 "mask("c27",'A','a','b')",                                                                 -- Convert uppercase letters in the c27 column to 'A', lowercase letters to 'a', and digits to 'b'.
  c28 "mask_first_n(c28,'A','a','b',5)",                                                        -- Convert the first 5 characters of the c28 column: uppercase letters to 'A', lowercase letters to 'a', and digits to 'b'.
  c29 "mask_last_n(c29,'A','a','b',5)",                                                         -- Convert the last 5 characters of the c29 column: uppercase letters to 'A', lowercase letters to 'a', and digits to 'b'.
  c30 "mask_show_first_n(c30,'A','a','b',5)",                                                   -- Convert all characters except the first 5 of the c30 column: uppercase letters to 'A', lowercase letters to 'a', and digits to 'b'.
  c31 "mask_show_last_n(c31,'A','a','b',5)"                                                     -- Convert all characters except the last 5 of the c31 column: uppercase letters to 'A', lowercase letters to 'a', and digits to 'b'.
);