Configure the Informix Native Client on Unix-like OS

Use the following steps to configure the Informix native client to connect to the desired Informix DBMS.

Log in to the Informix server host as the Informix user.
Ensure that the Informix environment is properly set. Minimally, $INFORMIXDIR and $INFORMIXSERVER must be set correctly for the target instance. The following command --
```
env | grep INF
```
-- should get results similar to these --
```
-bash-2.05b$ env | grep INF
INFORMIXDIR=/dbs/informix/IDS10
INFORMIXSERVER=opllinux3
-bash-2.05b$ 
```

Execute the following commands exactly as written --


cd $INFORMIXDIR/etc
grep `echo $INFORMIXSERVER` sqlhosts

You should get output like this --


-bash-2.05b$ cd $INFORMIXDIR/etc
-bash-2.05b$ grep `echo $INFORMIXSERVER` sqlhosts 
opllinux3 onsoctcp 	opllinux3	inf10srv 
-bash-2.05b$

There are 4 columns in the output. You'll need information related to each column, though it may not be the value you see there.
- The first column of the output should be the value seen earlier for $INFORMIXSERVER.
- The second column shows the connection protocol supported by this $INFORMIXSERVER, e.g., onsoctcp, ontlitcp. NOTE: If the connection protocol name does not include "tcp," you cannot connect directly to this instance over the network, and you cannot use our Single-Tier solution unless it is being used directly on the Informix server host. You can use our Multi-Tier solution, if you can install some OpenLink components directly on the Informix server host.
- The third column shows the hostname or IP address of the machine on which the Informix server runs. The hostname used here may be short (infhost) or fully-qualified (infhost.example.com); you need to know the fully-qualified DNS-resolvable hostname or the IP address for the client configuration. You can use the following commands to learn the needed value(s) --
```
hostname
host `hostname`
/sbin/ifconfig
host <ip address from ifconfig>
nslookup <ip address from ifconfig>
```
- The fourth column shows the port name or number for the Informix listener. If it's a name, you'll need to get the port number from /etc/services --
```
grep inf10srv /etc/services
```
  -- like so --
```
-bash-2.05b$ grep inf10srv /etc/services
inf10srv	5678/tcp			# Informix 10 server
-bash-2.05b$ 
```
Log out of the Informix server host, and log in to the Single-Tier client host, again as the Informix user. If you haven't already downloaded and installed the Informix Client SDK, now is the time to do so.
Ensure that the Informix environment is properly set. Minimally, $INFORMIXDIR must be set correctly for the Client SDK, and $INFORMIXSERVER must be set correctly for the target instance. The following command --
```
env | grep INF
```
-- should get results similar to these --
```
-bash-2.05b$ env | grep INF
INFORMIXDIR=/dbs/informix/CSDK10
INFORMIXSERVER=opllinux3
-bash-2.05b$ 
```
Edit (or create, if necessary) the $INFORMIXDIR/etc/sqlhosts file and add a line similar to the one you got from the Informix server, along these lines --
```
<$INFORMIXSERVER>     <protocol>     <hostname or IP address>     <service name or port number>
```
For example --
```
informix_tcp     onsoctcp     192.168.123.231     inf10srv
```
NOTE: If you use a service name here, you must also add an appropriate line to /etc/services. For best results, the service name should be the same on both server and client hosts, and it must use the same port number.
```
inf10srv	5678/tcp			# remote Informix 10 server
```
Save and exit the file.