[pkgsrc/trunk]: pkgsrc/doc/guide/files Documented the ${MASTER_SITE_FOO:=pack...

[rillig <rillig%pkgsrc.org@localhost>]

details:   https://anonhg.NetBSD.org/pkgsrc/rev/53bdf21da64b
branches:  trunk
changeset: 515020:53bdf21da64b
user:      rillig <rillig%pkgsrc.org@localhost>
date:      Thu Jun 22 07:30:38 2006 +0000

description:
Documented the ${MASTER_SITE_FOO:=package/} syntax, which may be
confusing to pkgsrc beginners. (At least it had been to me.)

diffstat:

 doc/guide/files/devfaq.xml |  24 ++++++++++++++++++++++--
 1 files changed, 22 insertions(+), 2 deletions(-)

diffs (44 lines):

diff -r 75399d818854 -r 53bdf21da64b doc/guide/files/devfaq.xml
--- a/doc/guide/files/devfaq.xml        Thu Jun 22 00:14:39 2006 +0000
+++ b/doc/guide/files/devfaq.xml        Thu Jun 22 07:30:38 2006 +0000
@@ -1,4 +1,4 @@
-<!-- $NetBSD: devfaq.xml,v 1.2 2006/05/10 16:19:55 rillig Exp $ -->
+<!-- $NetBSD: devfaq.xml,v 1.3 2006/06/22 07:30:38 rillig Exp $ -->
 
 <chapter id="devfaq"> <?dbhtml filename="devfaq.html"?>
 <title>Frequently Asked Questions</title>
@@ -63,7 +63,6 @@
        <answer><para>[FIXME]</para></answer>
 
 </qandaentry>
-
 <qandaentry>
 
        <question><para>Why does <command>make show-var
@@ -77,5 +76,26 @@
        command.</para></answer>
 
 </qandaentry>
+<qandaentry>
+
+       <question><para>What does
+       <literal>${MASTER_SITE_SOURCEFORGE:=package/}</literal> mean? I
+       don't understand the <literal>:=</literal> inside
+       it.</para></question>
+
+       <answer><para>The <literal>:=</literal> is not really an
+       assignment operator, like you might expect at first sight.
+       Instead, it is a degenerate form of
+       <literal>${LIST:<replaceable>old_string</replaceable>=<replaceable>new_string</replaceable>}</literal>,
+       which is documented in the &man.make.1; man page and which you
+       may have seen as in <literal>${SRCS:.c=.o}</literal>. In the
+       case of <varname>MASTER_SITE_*</varname>,
+       <replaceable>old_string</replaceable> is the empty string and
+       <replaceable>new_string</replaceable> is
+       <literal>package/</literal>. That's where the
+       <literal>:</literal> and the <literal>=</literal> fall
+       together.</para></answer>
+
+</qandaentry>
 </qandaset>
 </chapter>