reference environment variables from gdb scripts

[Eli Zaretskii]

> Date: Fri, 24 Aug 2007 09:37:25 -0700
> From: Sheng-Liang Song <ssl@baymicrosystems.com>
> 
> BTW, Is there a gdb script functional document?

The GDB scripting commands are documented in the GDB user manual.  See
the node "Sequences".