[oracle@test ~]$ cd /home/user/output/files
[oracle@test files]$ echo "test" >  test_20190129.txt
[oracle@test files]$ ls -all | grep test_20190129.txt
-rw------- 1 oracle  oinstall    5 Jan 29 test_20190129.txt
[oracle@test files]$



[user@test ~]$ ls -all output
total 20
drwxrwxrwx  5 user oinstall 4096 Jan 16 14:14 .
drwx------ 20 user      501 4096 Jan 22 10:57 ..
drwxrwxrwx  2 user oinstall 4096 Jan 16 14:14 files

SET SERVEROUTPUT ON
DECLARE
  v_Filename         VARCHAR2(255);
  v_Location          VARCHAR2(32767) := '/home/user/outfiles';
  v_Dir_Name        all_directories.Directory_Name%TYPE;  
  g_File                 UTL_FILE.FILE_TYPE;   
BEGIN
  v_Filename := 'test_' || To_Char(SYSDATE, 'yyyymmdd_hh24miss');
  DBMS_OUTPUT.PUT_LINE( 'Step 1' );  
  
  BEGIN 
	SELECT DIRECTORY_NAME INTO v_Dir_Name 
	  FROM ALL_DIRECTORIES 
	 WHERE directory_path = v_Location AND rownum = 1;  	 
  EXCEPTION
    WHEN NO_DATA_FOUND THEN
      DBMS_OUTPUT.PUT_LINE( 'Error! Can''t find directory ' || v_Location || ' in ALL_DIRECTORIES table!');	
      RAISE;
    WHEN OTHERS THEN
      RAISE;	 
  END;
	
  DBMS_OUTPUT.PUT_LINE( 'v_Dir_Name: '|| v_Dir_Name ); 

  g_File := UTL_FILE.FOPEN( location      => v_Dir_Name
                          , filename      => v_Filename
                          , open_mode     => 'w'
                          , max_linesize  => 32767
                          );
  DBMS_OUTPUT.PUT_LINE( 'Step 2' );								  
  UTL_FILE.PUT_LINE(g_File, 'test');								  
  DBMS_OUTPUT.PUT_LINE( 'Step 3' );  			
  UTL_FILE.fclose(g_File);  
  DBMS_OUTPUT.PUT_LINE( 'Step 4' );   
EXCEPTION   
    WHEN OTHERS THEN
      DBMS_OUTPUT.PUT_LINE( 'Error! '|| SQLERRM );  
END;
/
 
Step 1
v_Dir_Name: TEST_DIR
Error! ORA-29283: invalid file operation
ORA-06512: at "SYS.UTL_FILE", line
536
ORA-29283: invalid file operation
PL/SQL procedure successfully completed.