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

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

Parent Directory Parent Directory | Revision Log Revision Log | View Patch Patch

Revision 1.25 Revision 1.36
2<!DOCTYPE sections SYSTEM "/dtd/book.dtd"> 2<!DOCTYPE sections SYSTEM "/dtd/book.dtd">
3 3
4<!-- 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 -->
5<!-- See http://creativecommons.org/licenses/by-sa/1.0 --> 5<!-- See http://creativecommons.org/licenses/by-sa/1.0 -->
6 6
7<!-- $Header: /var/cvsroot/gentoo/xml/htdocs/doc/en/handbook/hb-working-use.xml,v 1.25 2004/12/26 14:56:32 swift Exp $ --> 7<!-- $Header: /var/cvsroot/gentoo/xml/htdocs/doc/en/handbook/hb-working-use.xml,v 1.36 2005/10/26 14:37:18 rane Exp $ -->
8 8
9<sections> 9<sections>
10 10
11<version>1.22</version> 11<version>1.31</version>
12<date>2004-12-26</date> 12<date>2005-10-26</date>
13 13
14<section> 14<section>
15<title>What are USE-flags?</title> 15<title>What are USE-flags?</title>
16<subsection> 16<subsection>
17<title>The ideas behind USE-flags</title> 17<title>The ideas behind USE-flags</title>
127<p> 127<p>
128As previously mentioned, all USE-flags are declared inside the <c>USE</c> 128As previously mentioned, all USE-flags are declared inside the <c>USE</c>
129variable. To make it easy for users to search and pick USE-flags, we already 129variable. To make it easy for users to search and pick USE-flags, we already
130provide a <e>default</e> USE setting. This setting is a collection of USE-flags 130provide a <e>default</e> USE setting. This setting is a collection of USE-flags
131we think are commonly used by the Gentoo users. This default setting is declared 131we think are commonly used by the Gentoo users. This default setting is declared
132in the <path>make.defaults</path> files part of your profile. Let us take a 132in the <path>make.defaults</path> files part of your profile.
133look at this default setting: 133</p>
134
134</p> 135<p>
136The profile your system listens to is pointed to by the
137<path>/etc/make.profile</path> symlink. Each profile works on top of another,
138larger profile, the end result is therefore the sum of all profiles. The top
139profile is the <path>base</path> profile
140(<path>/usr/portage/profiles/base</path>).
141</p>
135 142
136<pre caption="/usr/portage/profiles/default-linux/x86/2004.3/make.defaults USE variable"> 143<p>
137<comment>(This is an example and might have changed since it was taken)</comment> 144Let us take a look at this default setting for the 2004.3 profile:
138USE="x86 oss apm arts avi berkdb crypt cups encode foomaticdb gdbm gif gpm 145</p>
139 gtk gtk2 imlib jpeg kde gnome libg++ libwww mad mikmod motif mpeg ncurses 146
140 nls oggvorbis opengl pam pdflib png python qt quicktime readline sdl 147<pre caption="Cumulative make.defaults USE variable for the 2004.3 profile">
148<comment>(This example is the sum of the settings in base, default-linux,
149 default-linux/x86 and default-linux/x86/2004.3)</comment>
150USE="x86 oss apm arts avi berkdb bitmap-fonts crypt cups encode fortran f77
151 foomaticdb gdbm gif gpm gtk gtk2 imlib jpeg kde gnome libg++ libwww mad
152 mikmod motif mpeg ncurses nls oggvorbis opengl pam pdflib png python qt
141 slang spell ssl svga tcpd truetype X xml2 xmms xv zlib" 153 quicktime readline sdl spell ssl svga tcpd truetype X xml2 xmms xv zlib"
142</pre> 154</pre>
143 155
144<p> 156<p>
145As you can see, this variable already contains quite a lot of keywords. Do 157As you can see, this variable already contains quite a lot of keywords. Do
146<b>not</b> alter any <path>make.defaults</path> file to tailor 158<b>not</b> alter any <path>make.defaults</path> file to tailor
220</pre> 232</pre>
221 233
222</body> 234</body>
223</subsection> 235</subsection>
224<subsection> 236<subsection>
225<title>Inheriting USE-flags</title> 237<title>Automatic USE Flags</title>
226<body> 238<body>
227 239
228<p> 240<p>
229Some packages don't only listen to USE-flags, but also provide USE-flags. When 241After certain packages are installed, additional USE flags will automatically
230you install such a package, the USE-flag they provide is added to your USE 242be enabled for you if you do not explicitly disable them. To view the list
231setting. To view the list of packages that provide a USE-flag, check 243of packages that trigger automatic USE-flags, check
232<path>/etc/make.profile/use.defaults</path>: 244<path>/etc/make.profile/use.defaults</path> and the <path>use.defaults</path>
245files of the parent profiles.
233</p> 246</p>
234 247
235<pre caption="A snippet from /etc/make.profile/use.defaults"> 248<pre caption="A snippet from /etc/make.profile/use.defaults">
236gnome gnome-base/gnome 249gnome gnome-base/gnome
237gtk x11-libs/gtk+ 250gtk x11-libs/gtk+
246<title>Precedence</title> 259<title>Precedence</title>
247<body> 260<body>
248 261
249<p> 262<p>
250Of course there is a certain precedence on what setting has priority over the 263Of course there is a certain precedence on what setting has priority over the
251USE setting. You don't want to declare <c>USE="-java"</c> only to see that 264USE setting. You don't want to declare <c>USE="-java"</c> only to see that
252<c>java</c> is declared anyway. The precedence for the USE setting is, ordered 265<c>java</c> is still used due to a setting that has a higher priority.
266The precedence for the USE setting is, ordered
253by priority (first has lowest priority): 267by priority (first has lowest priority):
254</p> 268</p>
255 269
256<ol> 270<ol>
257 <li> 271 <li>
258 Default USE setting declared in the <path>make.defaults</path> files part of 272 Default USE setting declared in the <path>make.defaults</path> files part of
259 your profile 273 your profile
260 </li> 274 </li>
261 <li> 275 <li>
262 Inherited USE setting if a package from 276 Inherited USE setting if a package from profile <path>use.defaults</path> is installed
263 <path>/etc/make.profile/use.defaults</path> is installed
264 </li> 277 </li>
265 <li> 278 <li>
266 User-defined USE setting in <path>/etc/make.conf</path> 279 User-defined USE setting in <path>/etc/make.conf</path>
267 </li> 280 </li>
268 <li> 281 <li>
272 User-defined USE setting as environment variable 285 User-defined USE setting as environment variable
273 </li> 286 </li>
274</ol> 287</ol>
275 288
276<p> 289<p>
277To view the final <c>USE</c> setting as seen by Portage, run <c>emerge info</c>. 290To view the final <c>USE</c> setting as seen by Portage, run <c>emerge
278This will list all relevant variables (including the <c>USE</c> variable) with 291--info</c>. This will list all relevant variables (including the <c>USE</c>
279the content used by Portage. 292variable) with the content used by Portage.
280</p> 293</p>
281 294
282<pre caption="Running emerge info"> 295<pre caption="Running emerge --info">
283# <i>emerge info</i> 296# <i>emerge --info</i>
284</pre> 297</pre>
285 298
286</body> 299</body>
287</subsection> 300</subsection>
288<subsection> 301<subsection>
303were emerged on your "old" system but that have been obsoleted by the new USE 316were emerged on your "old" system but that have been obsoleted by the new USE
304flags. 317flags.
305</p> 318</p>
306 319
307<warn> 320<warn>
308Running <c>emerge depclean</c> is a dangerous operation and should be handled 321Running <c>emerge --depclean</c> is a dangerous operation and should be handled
309with care. Double-check the provided list of "obsoleted" packages to make sure 322with care. Double-check the provided list of "obsoleted" packages to make sure
310it doesn't remove packages you need. In the following example we add the 323it doesn't remove packages you need. In the following example we add the
311<c>-p</c> switch to have depclean only list the packages without removing them. 324<c>-p</c> switch to have depclean only list the packages without removing them.
312</warn> 325</warn>
313 326
314<pre caption="Removing obsoleted packages"> 327<pre caption="Removing obsoleted packages">
315# <i>emerge -p depclean</i> 328# <i>emerge -p --depclean</i>
316</pre> 329</pre>
317 330
318<p> 331<p>
319When depclean has finished, run <c>revdep-rebuild</c> to rebuild the 332When depclean has finished, run <c>revdep-rebuild</c> to rebuild the
320applications that are dynamically linked against shared objects provided by 333applications that are dynamically linked against shared objects provided by
355-moznocompose -moznoxft 368-moznocompose -moznoxft
356</pre> 369</pre>
357 370
358<p> 371<p>
359<c>emerge</c> isn't the only tool for this job. In fact, we have a tool 372<c>emerge</c> isn't the only tool for this job. In fact, we have a tool
360dedicated to package information called <c>etcat</c> which resides in the 373dedicated to package information called <c>equery</c> which resides in the
361<c>gentoolkit</c> package. First, install <c>gentoolkit</c>: 374<c>gentoolkit</c> package. First, install <c>gentoolkit</c>:
362</p> 375</p>
363 376
364<pre caption="Installing gentoolkit"> 377<pre caption="Installing gentoolkit">
365# <i>emerge gentoolkit</i> 378# <i>emerge gentoolkit</i>
366</pre> 379</pre>
367 380
368<p> 381<p>
369Now run <c>etcat</c> with the <c>uses</c> argument to view the USE-flags of a 382Now run <c>equery</c> with the <c>uses</c> argument to view the USE-flags of a
370certain package. For instance, for the <c>gnumeric</c> package: 383certain package. For instance, for the <c>gnumeric</c> package:
371</p> 384</p>
372 385
373<pre caption="Using etcat to view used USE-flags"> 386<pre caption="Using equery to view used USE-flags">
374# <i>etcat uses gnumeric</i> 387# <i>equery uses gnumeric</i>
375[ Colour Code : <i>set</i> <comment>unset</comment> ] 388[ Colour Code : <i>set</i> <comment>unset</comment> ]
376[ Legend : (U) Col 1 - Current USE flags ] 389[ Legend : (U) Col 1 - Current USE flags ]
377[ : (I) Col 2 - Installed With USE flags ] 390[ : (I) Col 2 - Installed With USE flags ]
378 391
379 U I [ Found these USE variables in : app-office/gnumeric-1.2.0 ] 392 U I [ Found these USE variables in : app-office/gnumeric-1.2.0 ]

Legend:
Removed from v.1.25  
changed lines
  Added in v.1.36

  ViewVC Help
Powered by ViewVC 1.1.20