UTL FILE
	It is a PL/SQL package that can be used to read/write to operating system files on a local
system, where the database resides.

List of UTL FILE subprograms

FCLOSE		:	Closing a file
FCLOSE_ALL	:	Closes all file handlers
FCOPY		:	Copies a part of the file to the newly created file
FFLUSH		:	Writes all pending output to the file
FGETATTR	:	Reads and returns the attributes of a disk file. ex file name,file length,location.
FGETPOS	:	Returns the current relative offset position with in a file to byte as binary integer
FOPEN		:	Opens a file for input or output
FOPEN_NCHAR	:	Unicode for input or output
FREMOVE	:	Deletes a diskfile location and file name
FRENAME	:	Renames existing to a new file name
FSEEK		:	Adjusts the file pointer backward/forward
GET_LINE	:	Reads text, following are the parameters (file, buffer, length)
GET_LINE_NCHAR	:	Reads text in unicode
GET_ROW	:	Reads a row string values
IS_OPEN		:	Determines if a file handle refers to an open file
NEW_LINE	:	Writes one or more operating system specific line terminators to a new file (file, lines)
PUT		:	Writes a string to a file
PUT_LINE	:	Writes a line to a file & also appends an operating system specific terminator, if already written it starts then new line with CR/LF.
PUT_LINE_NCHAR	:	Writes a unicode string to a file
PUTF		:	Formatting
PUTF_NCHAR	:	Writes unicode string to file for formatting
PUT_RAW	:	Accepts input as raw data value & writes the values to a output buffer


Sample program ( With Error)

create or replace procedure sal_status(p_filedir in varchar2, p_filename in varchar2)
is
v_filehandle UTL_FILE.FILE_TYPE;
cursor emp_info is 
	select last_name,salary,department_id from employees order by department_id;
v_newdeptno employees.department_id%type;
v_olddeptno employees.department_id%type :=0;

begin

v_filehandle :=UTL_FILE.FOPEN (p_filedir, p_filename, 'W');
UTL_FILE.PUTF (v_filehandle, 'SALARY REPORT GENERATED ON %s\n', sysdate);
UTL_FILE.NEW_LINE (v_filehandle);
for v_emp_rec in emp_info loop
v_newdeptno:=v_emp_rec.department_id;
if v_newdeptno!=v_olddeptno then
UTL_FILE.PUTF(v_filehandle, 'DEPARTMENT: %s\n', v_emp_rec.department_id);
end if;
UTL_FILE.PUTF(v_filehandle, ' EMPLOYEE: %s earns : %s\n', v_emp_rec.last_name,v_emp_rec.salary);
v_olddeptno:=v_newdeptno;
end loop;
UTL_FILE.PUT_LINE(v_filehandle, '    END OF REPORT   ');
UTL_FILE.FCLOSE(v_filehandle);
EXCEPTION
when UTL_FILE.INVALID_FILEHANDLE then
RAISE_APPLICATION_ERROR (-20008, ' Invalid file');
when UTL_FILE.WRITE.ERROR then
RAISE_APPLICATION_ERROR (-20003, ' unable to write');
end sal_status;
/

EXCEPTIONS IN UTL_FILE

Invalid_path	;	Invalid filename of file location
Invalid_mode	:	Parameter in fopen is invalid
Invalid_filehandle	:	Invalid file handle
Invalid_operation	:	Could not be opened or operated 
Read_error	:	An operating system error occured during read operation
Write_error	:	An operating system error occured during write operation
internal_error	:	An unspecified error in PL/SQL