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6.2 Useful Variables

Variable: system:*stdin* ¶

Variable: system:*stdout* ¶

Variable: system:*stderr* ¶

Streams connected to the standard input, output and error file descriptors.

Variable: system:*tty* ¶

A stream connected to /dev/tty.

Variable: extensions:*environment-list* ¶

The environment variables inherited by the current process, as a keyword-indexed alist. For example, to access the DISPLAY environment variable, you could use

   (cdr (assoc :display ext:*environment-list*))

Note that the case of the variable name is preserved when converting to a keyword. Therefore, you need to specify the keyword properly for variable names containing lower-case letters,