Advanced Oracle PL/SQL Programming with Packages

5.11. PLVfile: Operating System I/O Manager

The PLVfile (PL/Vision FILE) package manages operating system I/O by providing a layer of code around Oracle's builtin UTL_FILE package. See Chapter 13 for details.

5.11.1. Package constants and exceptions

max_line_size CONSTANT INTEGER := 1000;

The maximum size of a line allowed to be read or written with PLVfile.

max_line VARCHAR2(1000);

I had to "hard code" the 1000 again in this declaration because you must supply a literal when you declare a length for a VARCHAR2 string. Predefined variable you can use to anchor declarations of local variables in your own programs that will hold the maximum length line allowed in PLVfile.

c_append CONSTANT VARCHAR2(1) := 'A';
c_read CONSTANT VARCHAR2(1) := 'R';
c_write CONSTANT VARCHAR2(1) := 'W';

The different types of file access allowed with the UTL_FILE builtin package (A = append to existing lines in file, R = read-only from file and W = write over existing contents of file).

c_unixdelim CONSTANT VARCHAR2(1) := '/';
c_dosdelim CONSTANT VARCHAR2(1) := '\';

Predefined operating system directory/path delimiters for UNIX and MS-DOS.

5.11.2. Trace PLVfile activity

PROCEDURE show;

Turns on the trace of PLVfile activity.

PROCEDURE noshow;

Turns off the trace of PLVfile activity (default setting).

FUNCTION showing RETURN BOOLEAN;

Returns TRUE if you are currently tracing PLVfile activity.

5.11.3. Setting the operating system delimiter

PROCEDURE set_delim (delim_in IN VARCHAR2);