home-environment: describe session variable values a bit

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Robert Helgesson 2018-01-04 12:19:34 +01:00
parent 33af9948e5
commit df6590abfc
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@ -128,6 +128,15 @@ in
description = ''
Environment variables to always set at login.
</para><para>
The values may refer to other environment variables using
POSIX.2 style variable references. For example, a variable
<varname>parameter</varname> may be referenced as
<code>$parameter</code> or <code>''${parameter}</code>. A
default value <literal>foo</literal> may be given as per
<code>''${parameter:-foo}</code> and, similarly, an alternate
value <literal>bar</literal> can be given as per
<code>''${parameter:+bar}</code>.
</para><para>
Note, these variables may be set in any order so no session
variable may have a runtime dependency on another session
variable. In particular code like