Where to Set Environment Variables on UNIX

You can set environment variables on UNIX in the following places:

• At the system prompt on the command line

  When you set an environment variable at the system prompt, you must reassign it the next time you log into the system. See also Using Environment Variables on UNIX.

• In an environment-configuration file

  An environment-configuration file is a common or private file where you can set all the environment variables that IBM Informix products use. The use of such files reduces the number of environment variables that you must set at the command line or in a shell file.

• In a login file

  Values of environment variables set in your .login, .cshrc, or .profile file are assigned automatically every time you log into the system.

• In the SET ENVIRONMENT statement of SQL

  Values of some environment variables can reset by the SET ENVIRONMENT statement. The scope of the new settings is generally the routine that executed the SET ENVIRONMENT statement, but it is the current session for the OPTCOMPIND environment variable of Dynamic Server, as described in the section OPTCOMPIND, and for environment variables of Extended Parallel Server that the sysdbopen( ) or sysdbclose( ) SPL routines can set. For more information on these routines and on the SET ENVIRONMENT statement, see the IBM Informix: Guide to SQL Syntax.

In IBM Informix ESQL/C, you can set supported environment variables within an application with the putenv( ) system call and retrieve values with the getenv( ) system call, if your UNIX system supports these functions. For more information on putenv( ) and getenv( ), see the IBM Informix: ESQL/C Programmer's Manual and your C documentation.