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authorTheodore A. Roth <taroth@gmail.com>2009-03-02 20:08:09 (GMT)
committerRichard Purdie <rpurdie@linux.intel.com>2010-02-10 16:25:35 (GMT)
commitbf6a4fd658a3c07edd4565c6a139537fa10fd456 (patch)
tree85cd6e1d244732cd87d9d5d5df7f21a256217bef /bitbake/doc
parent6ae39074331d7296a7516a63e2e7ce435bc5559d (diff)
downloadpoky-bf6a4fd658a3c07edd4565c6a139537fa10fd456.tar.gz
bitbake: usermanual.xml: Add section for ?= var setting.
(Bitbake rev: df8309c11a43a9488ca25ec114a2dd3d49b041ff) Signed-off-by: Richard Purdie <rpurdie@linux.intel.com>
Diffstat (limited to 'bitbake/doc')
-rw-r--r--bitbake/doc/manual/usermanual.xml5
1 files changed, 5 insertions, 0 deletions
diff --git a/bitbake/doc/manual/usermanual.xml b/bitbake/doc/manual/usermanual.xml
index cdd0599..c340344 100644
--- a/bitbake/doc/manual/usermanual.xml
+++ b/bitbake/doc/manual/usermanual.xml
@@ -89,6 +89,11 @@ share common metadata between many packages.</para></listitem>
89 <para>This results in <varname>A</varname> containing <literal>aval</literal> and <varname>B</varname> containing <literal>preavalpost</literal>.</para> 89 <para>This results in <varname>A</varname> containing <literal>aval</literal> and <varname>B</varname> containing <literal>preavalpost</literal>.</para>
90 </section> 90 </section>
91 <section> 91 <section>
92 <title>Setting a default value (?=)</title>
93 <para><screen><varname>A</varname> ?= "aval"</screen></para>
94 <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>
95 </section>
96 <section>
92 <title>Immediate variable expansion (:=)</title> 97 <title>Immediate variable expansion (:=)</title>
93 <para>:= results in a variable's contents being expanded immediately, rather than when the variable is actually used.</para> 98 <para>:= results in a variable's contents being expanded immediately, rather than when the variable is actually used.</para>
94 <para><screen><varname>T</varname> = "123" 99 <para><screen><varname>T</varname> = "123"