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| author |   Theodore A. Roth <taroth@gmail.com> | 2009-03-02 12:08:09 -0800 |
|---|---|---|
| committer |   Richard Purdie <rpurdie@linux.intel.com> | 2010-01-21 10:57:28 +0000 |
| commit | df8309c11a43a9488ca25ec114a2dd3d49b041ff (patch) | |
| tree | af594b91b9bf3fe5592e75c3c1404a0a1149471b /doc | |
| parent | 74979370eff1a8b7b7f8a4ca146ad9d4bf83c9af (diff) | |
| download | bitbake-df8309c11a43a9488ca25ec114a2dd3d49b041ff.tar.gz | |
usermanual.xml: Add section for ?= var setting.
Signed-off-by: Richard Purdie <rpurdie@linux.intel.com>
Diffstat (limited to 'doc')
| -rw-r--r-- | doc/manual/usermanual.xml | 5 |
1 files changed, 5 insertions, 0 deletions
diff --git a/doc/manual/usermanual.xml b/doc/manual/usermanual.xml index cdd05998a..c3403449f 100644 --- a/doc/manual/usermanual.xml +++ b/doc/manual/usermanual.xml @@ -89,6 +89,11 @@ share common metadata between many packages.</para></listitem> <para>This results in <varname>A</varname> containing <literal>aval</literal> and <varname>B</varname> containing <literal>preavalpost</literal>.</para> </section> <section> + <title>Setting a default value (?=)</title> + <para><screen><varname>A</varname> ?= "aval"</screen></para> + <para>If <varname>A</varname> is set before the above is called, it will retain it's previous value. If <varname>A</varname> is unset prior to the above call, <varname>A</varname> will be set to <literal>aval</literal>.</para> + </section> + <section> <title>Immediate variable expansion (:=)</title> <para>:= results in a variable's contents being expanded immediately, rather than when the variable is actually used.</para> <para><screen><varname>T</varname> = "123" |