of the <productname>Postgres</productname>

<acronym>ODBC</acronym> package.

<varlistentry>

<term>

setuid to 256: failed to launch gateway

<listitem>

<para>

The September release of ApplixWare v4.4.1 (the first release with official

<acronym>ODBC</acronym> support under Linux) shows problems when usernames

exceed eight (8) characters in length.

Problem description ontributed by

<ulink url="mailto:scampbell@lear.com">Steve Campbell</ulink>.

</variablelist>

<para>

<note>

<title>Author</title>

<para>

Contributed by

<ulink url="mailto:scampbell@lear.com">Steve Campbell</ulink> on

1998-10-20.

</note>

The <application>axnet</application> program's security system

seems a little suspect. <application>axnet</application> does things

on behalf of the user and on a true

multiple user system it really should be run with root security

(so it can read/write in each user's directory).

I would hesitate to recommend this, however, since we have no idea what

security holes this creates.

<sect2>

<title>Debugging ApplixWare ODBC Connections</title>

<para>

One good tool for debugging connection problems uses the Unix system

utility <application>strace</application>.

<procedure>

<title>Debugging with strace</title>

<step performance="required">

<para>

Start applixware.

<step performance="required">

<para>

Start an <application>strace</application> on

the axnet process. For example, if

<programlisting>

ps -aucx | grep ax

</programlisting>

shows

<programlisting>

cary 10432 0.0 2.6 1740 392 ? S Oct 9 0:00 axnet

cary 27883 0.9 31.0 12692 4596 ? S 10:24 0:04 axmain

</programlisting>

<para>

Then run

<programlisting>

strace -f -s 1024 -p 10432

</programlisting>

<step performance="required">

<para>

Check the strace output.

<note>

<title>Note from Cary</title>

<para>

Many of the error messages from <productname>ApplixWare</productname>

go to <filename>stderr</filename>,

but I'm not sure where <filename>stderr</filename>

is sent, so <application>strace</application> is the way to find out.

</note>

</procedure>

<para>

For example, after getting

a <quote>Cannot launch gateway on server</quote>,

I ran strace on axnet and got

<programlisting>

[pid 27947] open("/usr/lib/libodbc.so", O_RDONLY) = -1 ENOENT

(No such file or directory)

[pid 27947] open("/lib/libodbc.so", O_RDONLY) = -1 ENOENT

(No such file or directory)

[pid 27947] write(2, "/usr2/applix/axdata/elfodbc:

can't load library 'libodbc.so'\n", 61) = -1 EIO (I/O error)

</programlisting>

So what is happening is that applix elfodbc is searching for libodbc.so, but it

can't find it. That is why axnet.cnf needed to be changed.

<sect2>

<title>Running the ApplixWare Demo</title>

<para>

In order to go through the

<citetitle>ApplixWare Data Tutorial</citetitle>, you need to create

the sample tables that the Tutorial refers to. The ELF Macro used to

create the tables tries to use a NULL condition

on many of the database columns,

and <productname>Postgres</productname> does not currently allow this option.

<para>

To get around this problem, you can do the following:

<procedure>

<title>Modifying the ApplixWare Demo</title>

<step performance="required">

<para>

Copy <filename>/opt/applix/axdata/eng/Demos/sqldemo.am</filename>

to a local directory.

<step performance="required">

<para>

Edit this local copy of <filename>sqldemo.am</filename>:

<substeps>

<step performance="required">

<para>

Search for 'null_clause = "NULL"

<step performance="required">

<para>

Change this to null_clause = ""

</substeps>

<step performance="required">

<para>

Start <application>Applix Macro Editor</application>.

<step performance="required">

<para>

Open the sqldemo.am file from the <application>Macro Editor</application>.

<step performance="required">

<para>

Select <command>File->Compile and Save</command>.

<step performance="required">

<para>

Exit <application>Macro Editor</application>.

<step performance="required">

<para>

Start <application>Applix Data</application>.

<step performance="required">

<para>

Select <command>*->Run Macro</command>

<step performance="required">

<para>

Enter the value <quote>sqldemo</quote>, then click <command>OK</command>.

<para>

You should see the progress in the status line of the data window

(in the lower left corner).

<step performance="required">

<para>

You should now be able to access the demo tables.

</procedure>

<sect2>

<title>Useful Macros</title>

<para>

You can add information about your

database login and password to the standard Applix startup

macro file. This is an example

<filename>~/axhome/macros/login.am</filename> file:

=======

<productname>ApplixWare</productname> must be configured correctly

in order for it to

be able to access the <productname>Postgres</productname>

<acronym>ODBC</acronym> software drivers.

<procedure>

<title>Enabling ApplixWare Database Access</title>

<para>

Note that

these instructions are for the 4.4.1 release of

<productname>ApplixWare</productname> on <productname>Linux</productname>.

Refer to the <citetitle>Linux Sys Admin</citetitle> on-line book

for more detailed information.

<step performance="required">

<para>

You must modify <filename>axnet.cnf</filename> so that

<filename>elfodbc</filename> can

find <filename>libodbc.so</filename>

(the <acronym>ODBC</acronym> driver manager) shared library.

This library is included with the ApplixWare distribution,

but <filename>axnet.cnf</filename> needs to be modified to point to the

correct location.

<para>

As root, edit the file

<filename><replaceable>applixroot</replaceable>/applix/axdata/axnet.cnf</filename>.

<substeps>

<step performance="required">

<para>

At the bottom of <filename>axnet.cnf</filename>,

find the line that starts with

<programlisting>

#libFor elfodbc /ax/<replaceable>...</replaceable>

</programlisting>

<step performance="required">

<para>

Change line to read

<programlisting>

libFor elfodbc <replaceable>applixroot</replaceable>/applix/axdata/axshlib/lib

</programlisting>

which will tell elfodbc to look in this directory

for the <acronym>ODBC</acronym> support library.

If you have installed applix somewhere else,

change the path accordingly.

</substeps>

<step performance="required">

<para>

Create <filename>.odbc.ini</filename> as

described above. You may also want to add the flag

<programlisting>

TextAsLongVarchar=0

</programlisting>

to the database-specific portion of <filename>.odbc.ini</filename>

so that text fields will not be shown as <literal>**BLOB**</literal>.

</procedure>

<procedure>

<title>Testing ApplixWare ODBC Connections</title>

<step performance="required">

<para>

Bring up <application>Applix Data</application>

<step performance="required">

<para>

Select the <productname>Postgres</productname> database of interest.

<substeps>

<step performance="required">

<para>

Select <command>Query->Choose Server</command>.

<step performance="required">

<para>

Select <acronym>ODBC</acronym>, and click <command>Browse</command>.

The database you configured in <filename>.odbc.ini</filename>

should be shown. Make sure that the <option>Host: field</option>

is empty (if it is not, axnet will try to contact axnet on another machine

to look for the database).

<step performance="required">

<para>

Select the database in the box that was launched by <command>Browse</command>,

then click <command>OK</command>.

<step performance="required">

<para>

Enter username and password in the login identification dialog,

and click <command>OK</command>.

</substeps>

<para>

You should see <quote>Starting elfodbc server</quote>

in the lower left corner of the

data window. If you get an error dialog box, see the debugging section

below.

<step performance="required">

<para>

The 'Ready' message will appear in the lower left corner of the data

window. This indicates that you can now enter queries.

<step performance="required">

<para>

Select a table from Query->Choose tables, and then select Query->Query

to access the database. The first 50 or so rows from the table should

appear.

</procedure>

<sect2>

<title>Common Problems</title>

<para>

The following messages can appear while trying to make an

<acronym>ODBC</acronym> connection through

<productname>Applix Data</productname>:

<variablelist>

<varlistentry>

<term>

Cannot launch gateway on server

<listitem>

<para>

<literal>elfodbc</literal> can't find <filename>libodbc.so</filename>.

Check your <filename>axnet.cnf</filename>.

<varlistentry>

<term>

Error from ODBC Gateway:

IM003::[iODBC][Driver Manager]Specified driver could not be loaded

<listitem>

<para>

<filename>libodbc.so</filename> cannot find the driver listed in

<filename>.odbc.ini</filename>. Verify the settings.

<varlistentry>

<term>

Server: Broken Pipe

<listitem>

<para>

The driver process has terminated due to some other

problem. You might not have an up-to-date version

of the <productname>Postgres</productname>

<acronym>ODBC</acronym> package.

</variablelist>

<sect2>