/[gentoo]/xml/htdocs/doc/en/handbook/hb-working-use.xml

Diff of /xml/htdocs/doc/en/handbook/hb-working-use.xml

Parent Directory | Revision Log | View Patch Patch

Revision 1.5		Revision 1.24
		1	<?xml version='1.0' encoding='UTF-8'?>
		2	<!DOCTYPE sections SYSTEM "/dtd/book.dtd">
		3
1	<!-- The content of this document is licensed under the CC-BY-SA license -->	4	<!-- The content of this document is licensed under the CC-BY-SA license -->
2	<!-- See http://creativecommons.org/licenses/by-sa/1.0 -->	5	<!-- See http://creativecommons.org/licenses/by-sa/1.0 -->
3		6
4	<!-- $Header: /var/cvsroot/gentoo/xml/htdocs/doc/en/handbook/hb-working-use.xml,v 1.5 2003/12/16 18:08:56 swift Exp $ -->	7	<!-- $Header: /var/cvsroot/gentoo/xml/htdocs/doc/en/handbook/hb-working-use.xml,v 1.24 2004/11/20 22:23:30 neysx Exp $ -->
5		8
6	<sections>	9	<sections>
		10
		11	<version>1.21</version>
		12	<date>2004-10-21</date>
		13
7	<section>	14	<section>
8	<title>What are USE-flags?</title>	15	<title>What are USE-flags?</title>
9	<subsection>	16	<subsection>
10	<title>The ideas behind USE-flags</title>	17	<title>The ideas behind USE-flags</title>
11	<body>	18	<body>
…		…
25	with KDE-support if those packages work flawlessly without?	32	with KDE-support if those packages work flawlessly without?
26	</p>	33	</p>
27		34
28	<p>	35	<p>
29	To help users in deciding what to install/activate and what not, we wanted the	36	To help users in deciding what to install/activate and what not, we wanted the
30	user to specify his environment in an easy way. This forces the user into	37	user to specify his/her environment in an easy way. This forces the user into
31	deciding what he really wants and eases the process for Portage, our package	38	deciding what they really want and eases the process for Portage, our package
32	managment system, to make useful decisions.	39	managment system, to make useful decisions.
33	</p>	40	</p>
34		41
35	</body>	42	</body>
36	</subsection>	43	</subsection>
…		…
44	Portage will know that you want support for the chosen keyword. Of course	51	Portage will know that you want support for the chosen keyword. Of course
45	this also alters the dependency information for a package.	52	this also alters the dependency information for a package.
46	</p>	53	</p>
47		54
48	<p>	55	<p>
49	Lets take a look at a specific example: the <c>kde</c> keyword. If you do not	56	Let us take a look at a specific example: the <c>kde</c> keyword. If you do not
50	have this keyword in your <c>USE</c> variable, all packages that have	57	have this keyword in your <c>USE</c> variable, all packages that have
51	<e>optional</e> KDE support will be compiled <e>without</e> KDE support. All	58	<e>optional</e> KDE support will be compiled <e>without</e> KDE support. All
52	packages that have an <e>optional</e> KDE dependency will be installed	59	packages that have an <e>optional</e> KDE dependency will be installed
53	<e>without</e> installing the KDE libraries (as dependency). If you have defined	60	<e>without</e> installing the KDE libraries (as dependency). If you have defined
54	the <c>kde</c> keyword, then those packages <e>will</e> be compiled with KDE	61	the <c>kde</c> keyword, then those packages <e>will</e> be compiled with KDE
…		…
74	<li>	81	<li>
75	A <e>global</e> USE-flag is used by several packages, system-wide. This is	82	A <e>global</e> USE-flag is used by several packages, system-wide. This is
76	what most people see as USE-flags.	83	what most people see as USE-flags.
77	</li>	84	</li>
78	<li>	85	<li>
79	A <e>local</e> USE-fag is used by a single package to make package-specific	86	A <e>local</e> USE-flag is used by a single package to make package-specific
80	decisions.	87	decisions.
81	</li>	88	</li>
82	</ul>	89	</ul>
83		90
84	<p>	91	<p>
…		…
96	icc - Use the Intel C++ Compiler if the package supports it	103	icc - Use the Intel C++ Compiler if the package supports it
97	icc-pgo - Enable PGO data generation or use when use icc.	104	icc-pgo - Enable PGO data generation or use when use icc.
98	imap - Adds support for IMAP	105	imap - Adds support for IMAP
99	</pre>	106	</pre>
100		107
		108	<p>
		109	A list of available local USE-flags can be found locally in
		110	<path>/usr/portage/profiles/use.local.desc</path>.
		111	</p>
		112
101	</body>	113	</body>
102	</subsection>	114	</subsection>
103	</section>	115	</section>
104	<section>	116	<section>
105	<title>Using USE-flags</title>	117	<title>Using USE-flags</title>
…		…
119	we think are commonly used by the Gentoo users. This default setting is declared	131	we think are commonly used by the Gentoo users. This default setting is declared
120	in the <path>/etc/make.profile/make.defaults</path> file. Let us take a look at	132	in the <path>/etc/make.profile/make.defaults</path> file. Let us take a look at
121	this default setting:	133	this default setting:
122	</p>	134	</p>
123		135
124	<pre caption="/etc/make.profile/make.defaults USE variable">	136	<pre caption="/etc/make.profile/make.defaults USE variable on an x86 system">
125	USE="x86 oss apm arts avi berkdb crypt cups encode foomaticdb gdbm gif gpm gtk	137	USE="x86 oss apm arts avi berkdb crypt cups encode foomaticdb gdbm gif gpm
126	imlib jpeg kde gnome libg++ libwww mad mikmod motif mpeg ncurses nls	138	gtk gtk2 imlib jpeg kde gnome libg++ libwww mad mikmod motif mpeg ncurses
127	oggvorbis opengl pam pdflib png python qt quicktime readline sdl slang	139	nls oggvorbis opengl pam pdflib png python qt quicktime readline sdl
128	spell ssl svga tcpd truetype X xml2 xmms xv zlib"	140	slang spell ssl svga tcpd truetype X xml2 xmms xv zlib"
129	</pre>	141	</pre>
130		142
131	<p>	143	<p>
132	As you can see, this variable already contains quite a lot of keywords. Do	144	As you can see, this variable already contains quite a lot of keywords. Do
133	<b>not</b> alter the <path>/etc/make.profile/make.defaults</path> file to tailor	145	<b>not</b> alter the <path>/etc/make.profile/make.defaults</path> file to tailor
…		…
153	</pre>	165	</pre>
154		166
155	</body>	167	</body>
156	</subsection>	168	</subsection>
157	<subsection>	169	<subsection>
		170	<title>Declaring USE flags for individual packages</title>
		171	<body>
		172
		173	<p>
		174	Sometimes you want to declare a certain USE flag for one (or a couple) of
		175	applications but not system-wide. To accomplish this, you will need to create
		176	the <path>/etc/portage</path> directory (if it doesn't exist yet) and edit
		177	<path>/etc/portage/package.use</path>.
		178	</p>
		179
		180	<p>
		181	For instance, if you don't want <c>berkdb</c> support globally but you do want
		182	it for <c>mysql</c>, you would add:
		183	</p>
		184
		185	<pre caption="/etc/portage/package.use example">
		186	dev-db/mysql berkdb
		187	</pre>
		188
		189	<p>
		190	You can of course also explicitly <e>disable</e> USE flags for a certain
		191	application. For instance, if you don't want <c>java</c> support in PHP:
		192	</p>
		193
		194	<pre caption="/etc/portage/package.use 2nd example">
		195	dev-php/php -java
		196	</pre>
		197
		198	</body>
		199	</subsection>
		200	<subsection>
158	<title>Declare temporary USE-flags</title>	201	<title>Declare temporary USE-flags</title>
159	<body>	202	<body>
160		203
161	<p>	204	<p>
162	Sometimes you want to set a certain USE-setting only once. Instead of editing	205	Sometimes you want to set a certain USE-setting only once. Instead of editing
163	<path>/etc/make.conf</path> twice (to do and undo the USE-changes) you can just	206	<path>/etc/make.conf</path> twice (to do and undo the USE-changes) you can just
164	declare the USE-variable as environment variable.	207	declare the USE-variable as environment variable. Remember that, when you
		208	re-emerge or update this application (either explicitly or as part of a system
		209	update) your changes will be lost!
165	</p>	210	</p>
166		211
167	<p>	212	<p>
168	As an example we will temporarily remove java from the USE-setting	213	As an example we will temporarily remove java from the USE-setting
169	during the installation of mozilla.	214	during the installation of mozilla.
170	</p>	215	</p>
171		216
172	<note>
173	The <c>emerge</c> command will be discussed more thoroughly in <uri
174	link="?part=2&chap=2">Portage and Software</uri>.
175	</note>
176
177	<pre caption="Using USE as evironment variable">	217	<pre caption="Using USE as environment variable">
178	# <i>USE="-java" emerge mozilla</i>	218	# <i>USE="-java" emerge mozilla</i>
179	</pre>	219	</pre>
180		220
181	</body>	221	</body>
182	</subsection>	222	</subsection>
…		…
200	</pre>	240	</pre>
201		241
202	</body>	242	</body>
203	</subsection>	243	</subsection>
204	<subsection>	244	<subsection>
205	<title>Precendence</title>	245	<title>Precedence</title>
206	<body>	246	<body>
207		247
208	<p>	248	<p>
209	Of course there is a certain precendence on what setting has priority over the	249	Of course there is a certain precedence on what setting has priority over the
210	USE setting. You don't want to declare <c>USE="-java"</c> only to see that	250	USE setting. You don't want to declare <c>USE="-java"</c> only to see that
211	<c>java</c> is declared anyway. The precedence for the USE setting is, ordered	251	<c>java</c> is declared anyway. The precedence for the USE setting is, ordered
212	by priority (first has lowest priority):	252	by priority (first has lowest priority):
213	</p>	253	</p>
214		254
…		…
222	</li>	262	</li>
223	<li>	263	<li>
224	User-defined USE setting in <path>/etc/make.conf</path>	264	User-defined USE setting in <path>/etc/make.conf</path>
225	</li>	265	</li>
226	<li>	266	<li>
		267	User-defined USE setting in <path>/etc/portage/package.use</path>
		268	</li>
		269	<li>
227	User-defined USE setting as environment variable	270	User-defined USE setting as environment variable
228	</li>	271	</li>
229	</ol>	272	</ol>
230		273
231	<p>	274	<p>
…		…
238	# <i>emerge info</i>	281	# <i>emerge info</i>
239	</pre>	282	</pre>
240		283
241	</body>	284	</body>
242	</subsection>	285	</subsection>
		286	<subsection>
		287	<title>Adapting your Entire System to New USE Flags</title>
		288	<body>
		289
		290	<p>
		291	If you have altered your USE flags and you wish to update your entire system to
		292	use the new USE flags, use <c>emerge</c>'s <c>--newuse</c> option:
		293	</p>
		294
		295	<pre caption="Rebuilding your entire system">
		296	# <i>emerge --update --deep --newuse world</i>
		297	</pre>
		298
		299	<p>
		300	Next, run Portage's depclean to remove the conditional dependencies that
		301	were emerged on your "old" system but that have been obsoleted by the new USE
		302	flags.
		303	</p>
		304
		305	<warn>
		306	Running <c>emerge depclean</c> is a dangerous operation and should be handled
		307	with care. Double-check the provided list of "obsoleted" packages to make sure
		308	it doesn't remove packages you need. In the following example we add the
		309	<c>-p</c> switch to have depclean only list the packages without removing them.
		310	</warn>
		311
		312	<pre caption="Removing obsoleted packages">
		313	# <i>emerge -p depclean</i>
		314	</pre>
		315
		316	<p>
		317	When depclean has finished, run <c>revdep-rebuild</c> to rebuild the
		318	applications that are dynamically linked against shared objects provided by
		319	possibly removed packages. <c>revdep-rebuild</c> is part of the
		320	<c>gentoolkit</c> package; don't forget to emerge it first.
		321	</p>
		322
		323	<pre caption="Running revdep-rebuild">
		324	# <i>revdep-rebuild</i>
		325	</pre>
		326
		327	<p>
		328	When all this is accomplished, your system is using the new USE flag settings.
		329	</p>
		330
		331	</body>
		332	</subsection>
243	</section>	333	</section>
244	<section>	334	<section>
245	<title>Package specific USE-flags</title>	335	<title>Package specific USE-flags</title>
246	<subsection>	336	<subsection>
247	<title>Viewing available USE-flags</title>	337	<title>Viewing available USE-flags</title>
248	<body>	338	<body>
249		339
250	<p>	340	<p>
251	In the next chapter on <uri link="?part=2&chap=2">Portage and Software</uri>
252	we will explain how to manage your installed software and how to work with
253	<c>emerge</c>. However, we will give you a primer on <c>emerge</c> by showing
254	you how to view what USE-flags a package uses.
255	</p>
256
257	<p>
258	Let us take the example of <c>mozilla</c>: what USE-flags does it listen to? To	341	Let us take the example of <c>mozilla</c>: what USE-flags does it listen to? To
259	find out, we use <c>emerge</c> with the <c>--pretend</c> (don't really do	342	find out, we use <c>emerge</c> with the <c>--pretend</c> and <c>--verbose</c>
260	anything) and <c>--verbose</c> (give more output) options:	343	options:
261	</p>	344	</p>
262		345
263	<pre caption="Viewing the used USE-flags">	346	<pre caption="Viewing the used USE-flags">
264	# <i>emerge --pretend --verbose mozilla</i>	347	# <i>emerge --pretend --verbose mozilla</i>
265	These are the packages that I would merge, in order:	348	These are the packages that I would merge, in order:
…		…
275	dedicated to package information called <c>etcat</c> which resides in the	358	dedicated to package information called <c>etcat</c> which resides in the
276	<c>gentoolkit</c> package. First, install <c>gentoolkit</c>:	359	<c>gentoolkit</c> package. First, install <c>gentoolkit</c>:
277	</p>	360	</p>
278		361
279	<pre caption="Installing gentoolkit">	362	<pre caption="Installing gentoolkit">
280	# <i>emerge --usepkg gentoolkit</i>	363	# <i>emerge gentoolkit</i>
281	</pre>	364	</pre>
282		365
283	<p>	366	<p>
284	Now run <c>etcat</c> with the <c>uses</c> argument to view the USE-flags of a	367	Now run <c>etcat</c> with the <c>uses</c> argument to view the USE-flags of a
285	certain package. For instance, for the <c>gnumeric</c> package:	368	certain package. For instance, for the <c>gnumeric</c> package:

 Legend:



Removed from v.1.5
 


changed lines


 
Added in v.1.24
 Legend:



Removed from v.1.5
 


changed lines


 
Added in v.1.24
-Removed from v.1.5
+Added in v.1.24

	ViewVC Help
Powered by ViewVC 1.1.13