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authorScott Rifenbark <srifenbark@gmail.com>2016-09-01 14:01:21 -0700
committerRichard Purdie <richard.purdie@linuxfoundation.org>2016-09-02 16:29:52 +0100
commit2f33bb30c705f1870a2e1d6de73e291250ad660d (patch)
tree8320ef78fe026e9a8e71a603fca3836abb089cc6 /bitbake
parent9b20975fc27ff6bc45c90e7aa8bbf67562450d6f (diff)
downloadpoky-2f33bb30c705f1870a2e1d6de73e291250ad660d.tar.gz
bitbake: bitbake-user-manual: Added "Exporting Variables to the Environment"
Fixes [YOCTO #10196] Added a new section named "Exporting Variables to the Environment". This section provides a dedicated description for how to export variables to the shell. (Bitbake rev: b543458dd67d24a228fa2db0ecb4ddd20016a560) Signed-off-by: Scott Rifenbark <srifenbark@gmail.com> Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>
Diffstat (limited to 'bitbake')
-rw-r--r--bitbake/doc/bitbake-user-manual/bitbake-user-manual-metadata.xml47
1 files changed, 47 insertions, 0 deletions
diff --git a/bitbake/doc/bitbake-user-manual/bitbake-user-manual-metadata.xml b/bitbake/doc/bitbake-user-manual/bitbake-user-manual-metadata.xml
index 64f08157f6..d4f73ae145 100644
--- a/bitbake/doc/bitbake-user-manual/bitbake-user-manual-metadata.xml
+++ b/bitbake/doc/bitbake-user-manual/bitbake-user-manual-metadata.xml
@@ -476,6 +476,53 @@
476 </section> 476 </section>
477 </section> 477 </section>
478 478
479 <section id='exporting-variables-to-the-environment'>
480 <title>Exporting Variables to the Environment</title>
481
482 <para>
483 You can export variables to the environment of running
484 tasks by using the <filename>export</filename> keyword.
485 For example, in the following example, the
486 <filename>do_foo</filename> task prints "value from
487 the environment" when run:
488 <literallayout class='monospaced'>
489 export ENV_VARIABLE
490 ENV_VARIABLE = "value from the environment"
491
492 do_foo() {
493 bbplain "$ENV_VARIABLE"
494 }
495 </literallayout>
496 <note>
497 BitBake does not expand <filename>$ENV_VARIABLE</filename>
498 in this case because it lacks the obligatory
499 <filename>{}</filename>.
500 Rather, <filename>$ENV_VARIABLE</filename> is expanded
501 by the shell.
502 </note>
503 It does not matter whether
504 <filename>export ENV_VARIABLE</filename> appears before or
505 after assignments to <filename>ENV_VARIABLE</filename>.
506 </para>
507
508 <para>
509 It is also possible to combine <filename>export</filename>
510 with setting a value for the variable.
511 Here is an example:
512 <literallayout class='monospaced'>
513 export ENV_VARIABLE = "<replaceable>variable-value</replaceable>"
514 </literallayout>
515 In the output of <filename>bitbake -e</filename>, variables
516 that are exported to the environment are preceded by "export".
517 </para>
518
519 <para>
520 Among the variables commonly exported to the environment
521 are <filename>CC</filename> and <filename>CFLAGS</filename>,
522 which are picked up by many build systems.
523 </para>
524 </section>
525
479 <section id='conditional-syntax-overrides'> 526 <section id='conditional-syntax-overrides'>
480 <title>Conditional Syntax (Overrides)</title> 527 <title>Conditional Syntax (Overrides)</title>
481 528