An environment variable is a named object that contains information used by one or more applications. They are global to their specific operating systems. The Firebird server recognises and uses certain environment variables configured in Windows, Linux and other Unix systems.

The ISC_USER and ISC_PASSWORD environment variables in Firebird are designed to give SYSDBA access to the database from the command-line utilities and client applications to anyone who has access to a host machine.

Caution: When running command-line utilities like isql, gbak, gstat and gfix, Firebird will search to see if the ISC_USER and ISC_PASSWORD environment variables are set. If you do not provide a user name and password while connecting to a database locally, Firebird will let you log in provided it finds these variables.

For security reasons, it is not advised to specify the SYSDBA user name and password using these two environment variables especially on an insecure computer.

The ISC_USER and ISC_PASSWORD environment variables may be set in order to start isql locally. To set the environment variables:

• In Windows 2000 / XP, this is done in the Control Panel → System → Advanced → Environment Variables. Any changes made here will be permanent. You may also define these variables in a command window prior to running any of the Firebird utilities, such as isql. For example:

C:\> set ISC_USER=sysdba
C:\> set ISC_PASSWORD=secret
C:\> isql my_employee

SQL>

• In Linux and Unix platforms, this depends on the type of shell being used and how the desktop is configured. Please refer to your operating system documentation to set environmental variables. For the bash shell, the following example shows the process:

cosmos> export ISC_USER=sysdba
cosmos> export ISC_PASSWORD=secret
cosmos> /opt/firebird/bin/isql my_employee

SQL>