Advanced Oracle PL/SQL Programming with Packages

13.2. Specifying the File in PLVfile

Now that you are aware of the way that UTL_FILE works, let's look at how PLVfile makes it easier to use the builtin package.

First of all, rather than insist that you separate out the file location from the file name to open and manipulate files, PLVfile provides a set of programs to make it easier to specify files. These programs are discussed below.

13.2.1. Setting the Operating System Delimiter

Each operating system has a delimiter that it uses to separate out directories and subdirectories, as well as separating directories from file names. Since PLVfile allows you to specify a file name as a single string (directory and file name combined), it needs to know about the operating system delimiter.

Use the set_delim to set the operating system delimiter. Its header is:

PROCEDURE set_delim (delim_in IN VARCHAR2);

You can find out the current operating system delimiter by calling the delim function:

FUNCTION delim RETURN VARCHAR2;

The PLVfile package offers two predefined delimiters for UNIX and DOS as shown:

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

The default, initial setting for the OS delimiter is the UNIX delimiter: "/".

13.2.2. Setting the Default Directory

PLVfile maintains a current directory so that you do not have to continually specify a directory if you are always working in the same area on disk. To set the current directory, call the set_dir procedure. To determine the current ...