Using Environment Variables to Assign Filerefs in UNIX Environments :: SAS(R) 9.3 Companion for UNIX Environments

Requirements for Variable Names

An environment variable can also be used as a fileref to refer to DISK files. The variable name must be in all uppercase characters, and the variable value must be the full pathname of the external file. That is, the filename must begin with a slash.

Note: If a variable and a fileref have the same name but refer to different files, SAS uses the fileref. For example, the %INCLUDE statement below refers to file /users/myid/this_one.

filename ABC '/users/myid/this_one';
x setenv ABC /users/myid/that_one;
%include ABC;

Reading a Data File

If you want to read the data file /users/myid/educ.dat, but you want to refer to it with the INED environment variable, you can define the variable at two times:

Before you invoke SAS, see Defining Environment Variables in UNIX Environments. For example, in the Korn shell, you use the following:
```
export INED=/users/myid/educ.dat
```
After you invoke SAS by using the X statement (see Executing Operating System Commands from Your SAS Session) and the SAS setenv command:
```
x setenv INED /users/myid/educ.dat;
```

After INED is associated with the file /users/myid/educ.dat, you can use ined as a fileref to refer to the file in the INFILE statement:

infile ined;

Writing to an External File

The same method applies if you want to write to an external file. For example, you can define OUTFILE before you invoke SAS:

OUTFILE=/users/myid/scores.dat
export OUTFILE

Then, use the environment variable name as a fileref to refer to the file:

file OUTFILE;