Extracting strings from binary data

Question

Hello,
I am trying to extract string from a binary file.
At the unix command line (sunos) I can just type;
strings <filename>
This is a nice way to get a list of the contents of a directory.
Is there a way in pl/sql to extract strings from binary data ? An equiv to strings on unix/linux ?
Thanks in advance.
Ben

Answer 1

Hi,
If you do want to list the contents of a directory, there are other ways to do it. Here's a base implementation of a utility I wrote:
create or replace and resolve java source named "Util" as
import java.io.*;
import java.sql.*;
import oracle.sql.*;
import oracle.jdbc.driver.*;
public class Util {
    public static void listFiles(String directory, oracle.sql.ARRAY[] names)
        throws IOException, SQLException {
        File f = new File(directory);
        if(f==null)
            throw new IOException("Directory: "+directory+" does not exist.");
        String[] files = f.list(
            new FilenameFilter() {
                public boolean accept(File dir, String name) {
                    // List all files
                    return true;
        Connection conn = new OracleDriver().defaultConnection();
        ArrayDescriptor descriptor = ArrayDescriptor.createDescriptor("VC_TAB_TYPE", conn);
        names[0] = new ARRAY(descriptor, conn, files);
        return;
create or replace type vc_tab_type is table of varchar2(255);
create or replace package util authid current_user as
    function list_files(p_directory in varchar2)
        return vc_tab_type;
end;
create or replace package body util as
    procedure list_files (
        p_directory in varchar2
        , p_filenames out nocopy vc_tab_type
    is
    language java
    name 'Util.listFiles(java.lang.String, oracle.sql.ARRAY[])';
    function list_files(p_directory in varchar2) return vc_tab_type
    is
        l_filenames vc_tab_type := vc_tab_type();
    begin
        list_files(p_directory, l_filenames);
        return l_filenames;
    end;
end;
/You can then query the filesystem as follows:
  1  select column_value as filename
  2  from table(util.list_files('c:\windows'))
  3  where column_value like '%.log'
  4* and rownum <= 10
SQL> /
FILENAME
0.log
AdfsOcm.log
aspnetocm.log
bkupinst.log
certocm.log
chipset.log
cmsetacl.log
comsetup.log
DtcInstall.log
FaxSetup.log
10 rows selected.cheers,
Anthony