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locale: unify some code between fedora and altlinux
[elogind.git] / man / systemd.exec.xml
1 <?xml version='1.0'?> <!--*-nxml-*-->
2 <?xml-stylesheet type="text/xsl" href="http://docbook.sourceforge.net/release/xsl/current/xhtml/docbook.xsl"?>
3 <!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.2//EN"
4         "http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd">
5
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7   This file is part of systemd.
8
9   Copyright 2010 Lennart Poettering
10
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14   (at your option) any later version.
15
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19   General Public License for more details.
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24
25 <refentry id="systemd.exec">
26         <refentryinfo>
27                 <title>systemd.exec</title>
28                 <productname>systemd</productname>
29
30                 <authorgroup>
31                         <author>
32                                 <contrib>Developer</contrib>
33                                 <firstname>Lennart</firstname>
34                                 <surname>Poettering</surname>
35                                 <email>lennart@poettering.net</email>
36                         </author>
37                 </authorgroup>
38         </refentryinfo>
39
40         <refmeta>
41                 <refentrytitle>systemd.exec</refentrytitle>
42                 <manvolnum>5</manvolnum>
43         </refmeta>
44
45         <refnamediv>
46                 <refname>systemd.exec</refname>
47                 <refpurpose>systemd execution environment configuration</refpurpose>
48         </refnamediv>
49
50         <refsynopsisdiv>
51                 <para><filename>systemd.service</filename>,
52                 <filename>systemd.socket</filename>,
53                 <filename>systemd.mount</filename>,
54                 <filename>systemd.swap</filename></para>
55         </refsynopsisdiv>
56
57         <refsect1>
58                 <title>Description</title>
59
60                 <para>Unit configuration files for services, sockets
61                 mount points and swap devices share a subset of
62                 configuration options which define the execution
63                 environment of spawned processes.</para>
64
65                 <para>This man page lists the configuration options
66                 shared by these three unit types. See
67                 <citerefentry><refentrytitle>systemd.unit</refentrytitle><manvolnum>5</manvolnum></citerefentry>
68                 for the common options of all unit configuration
69                 files, and
70                 <citerefentry><refentrytitle>systemd.service</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
71                 <citerefentry><refentrytitle>systemd.socket</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
72                 <citerefentry><refentrytitle>systemd.swap</refentrytitle><manvolnum>5</manvolnum></citerefentry>
73                 and
74                 <citerefentry><refentrytitle>systemd.mount</refentrytitle><manvolnum>5</manvolnum></citerefentry>
75                 for more information on the specific unit
76                 configuration files. The execution specific
77                 configuration options are configured in the [Service],
78                 [Socket], [Mount] resp. [Swap] section, depending on the unit
79                 type.</para>
80         </refsect1>
81
82         <refsect1>
83                 <title>Options</title>
84
85                 <variablelist>
86
87                         <varlistentry>
88                                 <term><varname>WorkingDirectory=</varname></term>
89
90                                 <listitem><para>Takes an absolute
91                                 directory path. Sets the working
92                                 directory for executed
93                                 processes.</para></listitem>
94                         </varlistentry>
95
96                         <varlistentry>
97                                 <term><varname>RootDirectory=</varname></term>
98
99                                 <listitem><para>Takes an absolute
100                                 directory path. Sets the root
101                                 directory for executed processes, with
102                                 the
103                                 <citerefentry><refentrytitle>chroot</refentrytitle><manvolnum>2</manvolnum></citerefentry>
104                                 system call. If this is used it must
105                                 be ensured that the process and all
106                                 its auxiliary files are available in
107                                 the <function>chroot()</function>
108                                 jail.</para></listitem>
109                         </varlistentry>
110
111                         <varlistentry>
112                                 <term><varname>User=</varname></term>
113                                 <term><varname>Group=</varname></term>
114
115                                 <listitem><para>Sets the Unix user
116                                 resp. group the processes are executed
117                                 as. Takes a single user resp. group
118                                 name or ID as argument. If no group is
119                                 set the default group of the user is
120                                 chosen.</para></listitem>
121                         </varlistentry>
122
123                         <varlistentry>
124                                 <term><varname>SupplementaryGroups=</varname></term>
125
126                                 <listitem><para>Sets the supplementary
127                                 Unix groups the processes are executed
128                                 as. This takes a space separated list
129                                 of group names or IDs. This option may
130                                 be specified more than once in which
131                                 case all listed groups are set as
132                                 supplementary groups. This option does
133                                 not override but extends the list of
134                                 supplementary groups configured in the
135                                 system group database for the
136                                 user.</para></listitem>
137                         </varlistentry>
138
139                         <varlistentry>
140                                 <term><varname>Nice=</varname></term>
141
142                                 <listitem><para>Sets the default nice
143                                 level (scheduling priority) for
144                                 executed processes. Takes an integer
145                                 between -20 (highest priority) and 19
146                                 (lowest priority). See
147                                 <citerefentry><refentrytitle>setpriority</refentrytitle><manvolnum>2</manvolnum></citerefentry>
148                                 for details.</para></listitem>
149                         </varlistentry>
150
151                         <varlistentry>
152                                 <term><varname>OOMScoreAdjust=</varname></term>
153
154                                 <listitem><para>Sets the adjustment
155                                 level for the Out-Of-Memory killer for
156                                 executed processes. Takes an integer
157                                 between -1000 (to disable OOM killing
158                                 for this process) and 1000 (to make
159                                 killing of this process under memory
160                                 pressure very likely). See <ulink
161                                 url="http://www.kernel.org/doc/Documentation/filesystems/proc.txt">proc.txt</ulink>
162                                 for details.</para></listitem>
163                         </varlistentry>
164
165                         <varlistentry>
166                                 <term><varname>IOSchedulingClass=</varname></term>
167
168                                 <listitem><para>Sets the IO scheduling
169                                 class for executed processes. Takes an
170                                 integer between 0 and 3 or one of the
171                                 strings <option>none</option>,
172                                 <option>realtime</option>,
173                                 <option>best-effort</option> or
174                                 <option>idle</option>. See
175                                 <citerefentry><refentrytitle>ioprio_set</refentrytitle><manvolnum>2</manvolnum></citerefentry>
176                                 for details.</para></listitem>
177                         </varlistentry>
178
179                         <varlistentry>
180                                 <term><varname>IOSchedulingPriority=</varname></term>
181
182                                 <listitem><para>Sets the IO scheduling
183                                 priority for executed processes. Takes
184                                 an integer between 0 (highest
185                                 priority) and 7 (lowest priority). The
186                                 available priorities depend on the
187                                 selected IO scheduling class (see
188                                 above). See
189                                 <citerefentry><refentrytitle>ioprio_set</refentrytitle><manvolnum>2</manvolnum></citerefentry>
190                                 for details.</para></listitem>
191                         </varlistentry>
192
193                         <varlistentry>
194                                 <term><varname>CPUSchedulingPolicy=</varname></term>
195
196                                 <listitem><para>Sets the CPU
197                                 scheduling policy for executed
198                                 processes. Takes one of
199                                 <option>other</option>,
200                                 <option>batch</option>,
201                                 <option>idle</option>,
202                                 <option>fifo</option> or
203                                 <option>rr</option>. See
204                                 <citerefentry><refentrytitle>sched_setscheduler</refentrytitle><manvolnum>2</manvolnum></citerefentry>
205                                 for details.</para></listitem>
206                         </varlistentry>
207
208                         <varlistentry>
209                                 <term><varname>CPUSchedulingPriority=</varname></term>
210
211                                 <listitem><para>Sets the CPU
212                                 scheduling priority for executed
213                                 processes. Takes an integer between 1
214                                 (lowest priority) and 99 (highest
215                                 priority). The available priority
216                                 range depends on the selected CPU
217                                 scheduling policy (see above). See
218                                 <citerefentry><refentrytitle>sched_setscheduler</refentrytitle><manvolnum>2</manvolnum></citerefentry>
219                                 for details.</para></listitem>
220                         </varlistentry>
221
222                         <varlistentry>
223                                 <term><varname>CPUSchedulingResetOnFork=</varname></term>
224
225                                 <listitem><para>Takes a boolean
226                                 argument. If true elevated CPU
227                                 scheduling priorities and policies
228                                 will be reset when the executed
229                                 processes fork, and can hence not leak
230                                 into child processes. See
231                                 <citerefentry><refentrytitle>sched_setscheduler</refentrytitle><manvolnum>2</manvolnum></citerefentry>
232                                 for details. Defaults to false.</para></listitem>
233                         </varlistentry>
234
235                         <varlistentry>
236                                 <term><varname>CPUAffinity=</varname></term>
237
238                                 <listitem><para>Controls the CPU
239                                 affinity of the executed
240                                 processes. Takes a space-separated
241                                 list of CPU indexes. See
242                                 <citerefentry><refentrytitle>sched_setaffinity</refentrytitle><manvolnum>2</manvolnum></citerefentry>
243                                 for details.</para></listitem>
244                         </varlistentry>
245
246                         <varlistentry>
247                                 <term><varname>UMask=</varname></term>
248
249                                 <listitem><para>Controls the file mode
250                                 creation mask. Takes an access mode in
251                                 octal notation. See
252                                 <citerefentry><refentrytitle>umask</refentrytitle><manvolnum>2</manvolnum></citerefentry>
253                                 for details. Defaults to
254                                 0002.</para></listitem>
255                         </varlistentry>
256
257                         <varlistentry>
258                                 <term><varname>Environment=</varname></term>
259
260                                 <listitem><para>Sets environment
261                                 variables for executed
262                                 processes. Takes a space-separated
263                                 list of variable assignments. This
264                                 option may be specified more than once
265                                 in which case all listed variables
266                                 will be set. If the same variable is
267                                 set twice the later setting will
268                                 override the earlier setting. See
269                                 <citerefentry><refentrytitle>environ</refentrytitle><manvolnum>7</manvolnum></citerefentry>
270                                 for details.</para></listitem>
271                         </varlistentry>
272                         <varlistentry>
273                                 <term><varname>EnvironmentFile=</varname></term>
274                                 <listitem><para>Similar to
275                                 <varname>Environment=</varname> but
276                                 reads the environment variables from a
277                                 text file. The text file should
278                                 contain new-line separated variable
279                                 assignments. Empty lines and lines
280                                 starting with ; or # will be ignored,
281                                 which may be used for commenting. The
282                                 argument passed should be an absolute
283                                 file name, optionally prefixed with
284                                 "-", which indicates that if the file
285                                 does not exist it won't be read and no
286                                 error or warning message is
287                                 logged.</para></listitem>
288                         </varlistentry>
289
290                         <varlistentry>
291                                 <term><varname>StandardInput=</varname></term>
292                                 <listitem><para>Controls where file
293                                 descriptor 0 (STDIN) of the executed
294                                 processes is connected to. Takes one
295                                 of <option>null</option>,
296                                 <option>tty</option>,
297                                 <option>tty-force</option>,
298                                 <option>tty-fail</option> or
299                                 <option>socket</option>. If
300                                 <option>null</option> is selected
301                                 standard input will be connected to
302                                 <filename>/dev/null</filename>,
303                                 i.e. all read attempts by the process
304                                 will result in immediate EOF. If
305                                 <option>tty</option> is selected
306                                 standard input is connected to a TTY
307                                 (as configured by
308                                 <varname>TTYPath=</varname>, see
309                                 below) and the executed process
310                                 becomes the controlling process of the
311                                 terminal. If the terminal is already
312                                 being controlled by another process the
313                                 executed process waits until the current
314                                 controlling process releases the
315                                 terminal.
316                                 <option>tty-force</option>
317                                 is similar to <option>tty</option>,
318                                 but the executed process is forcefully
319                                 and immediately made the controlling
320                                 process of the terminal, potentially
321                                 removing previous controlling
322                                 processes from the
323                                 terminal. <option>tty-fail</option> is
324                                 similar to <option>tty</option> but if
325                                 the terminal already has a controlling
326                                 process start-up of the executed
327                                 process fails.  The
328                                 <option>socket</option> option is only
329                                 valid in socket-activated services,
330                                 and only when the socket configuration
331                                 file (see
332                                 <citerefentry><refentrytitle>systemd.socket</refentrytitle><manvolnum>5</manvolnum></citerefentry>
333                                 for details) specifies a single socket
334                                 only. If this option is set standard
335                                 input will be connected to the socket
336                                 the service was activated from, which
337                                 is primarily useful for compatibility
338                                 with daemons designed for use with the
339                                 traditional
340                                 <citerefentry><refentrytitle>inetd</refentrytitle><manvolnum>8</manvolnum></citerefentry>
341                                 daemon. This setting defaults to
342                                 <option>null</option>.</para></listitem>
343                         </varlistentry>
344                         <varlistentry>
345                                 <term><varname>StandardOutput=</varname></term>
346                                 <listitem><para>Controls where file
347                                 descriptor 1 (STDOUT) of the executed
348                                 processes is connected to. Takes one
349                                 of <option>inherit</option>,
350                                 <option>null</option>,
351                                 <option>tty</option>,
352                                 <option>syslog</option>,
353                                 <option>kmsg</option> or
354                                 <option>socket</option>. If set to
355                                 <option>inherit</option> the file
356                                 descriptor of standard input is
357                                 duplicated for standard output. If set
358                                 to <option>null</option> standard
359                                 output will be connected to
360                                 <filename>/dev/null</filename>,
361                                 i.e. everything written to it will be
362                                 lost. If set to <option>tty</option>
363                                 standard output will be connected to a
364                                 tty (as configured via
365                                 <varname>TTYPath=</varname>, see
366                                 below). If the TTY is used for output
367                                 only the executed process will not
368                                 become the controlling process of the
369                                 terminal, and will not fail or wait
370                                 for other processes to release the
371                                 terminal. <option>syslog</option>
372                                 connects standard output to the
373                                 <citerefentry><refentrytitle>syslog</refentrytitle><manvolnum>3</manvolnum></citerefentry>
374                                 system logger. <option>kmsg</option>
375                                 connects it with the kernel log buffer
376                                 which is accessible via
377                                 <citerefentry><refentrytitle>dmesg</refentrytitle><manvolnum>1</manvolnum></citerefentry>. <option>socket</option>
378                                 connects standard output to a socket
379                                 from socket activation, semantics are
380                                 similar to the respective option of
381                                 <varname>StandardInput=</varname>.
382                                 This setting defaults to
383                                 <option>inherit</option>.</para></listitem>
384                         </varlistentry>
385                         <varlistentry>
386                                 <term><varname>StandardError=</varname></term>
387                                 <listitem><para>Controls where file
388                                 descriptor 2 (STDERR) of the executed
389                                 processes is connected to. The
390                                 available options are identical to
391                                 those of
392                                 <varname>StandardOutput=</varname>,
393                                 with one exception: if set to
394                                 <option>inherit</option> the file
395                                 descriptor used for standard output is
396                                 duplicated for standard error. This
397                                 setting defaults to
398                                 <option>inherit</option>.</para></listitem>
399                         </varlistentry>
400                         <varlistentry>
401                                 <term><varname>TTYPath=</varname></term>
402                                 <listitem><para>Sets the terminal
403                                 device node to use if standard input,
404                                 output or stderr are connected to a
405                                 TTY (see above). Defaults to
406                                 <filename>/dev/console</filename>.</para></listitem>
407                         </varlistentry>
408                         <varlistentry>
409                                 <term><varname>SyslogIdentifer=</varname></term>
410                                 <listitem><para>Sets the process name
411                                 to prefix log lines sent to syslog or
412                                 the kernel log buffer with. If not set
413                                 defaults to the process name of the
414                                 executed process. This option is only
415                                 useful when
416                                 <varname>StandardOutput=</varname> or
417                                 <varname>StandardError=</varname> are
418                                 set to <option>syslog</option> or
419                                 <option>kmsg</option>.</para></listitem>
420                         </varlistentry>
421                         <varlistentry>
422                                 <term><varname>SyslogFacility=</varname></term>
423                                 <listitem><para>Sets the syslog
424                                 facility to use when logging to
425                                 syslog. One of <option>kern</option>,
426                                 <option>user</option>,
427                                 <option>mail</option>,
428                                 <option>daemon</option>,
429                                 <option>auth</option>,
430                                 <option>syslog</option>,
431                                 <option>lpr</option>,
432                                 <option>news</option>,
433                                 <option>uucp</option>,
434                                 <option>cron</option>,
435                                 <option>authpriv</option>,
436                                 <option>ftp</option>,
437                                 <option>local0</option>,
438                                 <option>local1</option>,
439                                 <option>local2</option>,
440                                 <option>local3</option>,
441                                 <option>local4</option>,
442                                 <option>local5</option>,
443                                 <option>local6</option> or
444                                 <option>local7</option>. See
445                                 <citerefentry><refentrytitle>syslog</refentrytitle><manvolnum>3</manvolnum></citerefentry>
446                                 for details. This option is only
447                                 useful when
448                                 <varname>StandardOutput=</varname> or
449                                 <varname>StandardError=</varname> are
450                                 set to <option>syslog</option>.
451                                 Defaults to
452                                 <option>daemon</option>.</para></listitem>
453                         </varlistentry>
454                         <varlistentry>
455                                 <term><varname>SyslogLevel=</varname></term>
456                                 <listitem><para>Default syslog level
457                                 to use when logging to syslog or the
458                                 kernel log buffer. One of
459                                 <option>emerg</option>,
460                                 <option>alert</option>,
461                                 <option>crit</option>,
462                                 <option>err</option>,
463                                 <option>warning</option>,
464                                 <option>notice</option>,
465                                 <option>info</option>,
466                                 <option>debug</option>. See
467                                 <citerefentry><refentrytitle>syslog</refentrytitle><manvolnum>3</manvolnum></citerefentry>
468                                 for details. This option is only
469                                 useful when
470                                 <varname>StandardOutput=</varname> or
471                                 <varname>StandardError=</varname> are
472                                 set to <option>syslog</option> or
473                                 <option>kmsg</option>. Note that
474                                 individual lines output by the daemon
475                                 might be prefixed with a different log
476                                 level which can be used to override
477                                 the default log level specified
478                                 here. The interpretation of these
479                                 prefixes may be disabled with
480                                 <varname>SyslogLevelPrefix=</varname>,
481                                 see below. For details see
482                                 <citerefentry><refentrytitle>sd-daemon</refentrytitle><manvolnum>7</manvolnum></citerefentry>.
483
484                                 Defaults to
485                                 <option>info</option>.</para></listitem>
486                         </varlistentry>
487
488                         <varlistentry>
489                                 <term><varname>SyslogLevelPrefix=</varname></term>
490                                 <listitem><para>Takes a boolean
491                                 argument. If true and
492                                 <varname>StandardOutput=</varname> or
493                                 <varname>StandardError=</varname> are
494                                 set to <option>syslog</option> or
495                                 <option>kmsg</option> log lines
496                                 written by the executed process that
497                                 are prefixed with a log level will be
498                                 passed on to syslog with this log
499                                 level set but the prefix removed. If
500                                 set to false, the interpretation of
501                                 these prefixes is disabled and the
502                                 logged lines are passed on as-is. For
503                                 details about this prefixing see
504                                 <citerefentry><refentrytitle>sd-daemon</refentrytitle><manvolnum>7</manvolnum></citerefentry>.
505                                 Defaults to true.</para></listitem>
506                         </varlistentry>
507
508                         <varlistentry>
509                                 <term><varname>TimerSlackNSec=</varname></term>
510                                 <listitem><para>Sets the timer slack
511                                 in nanoseconds for the executed
512                                 processes. The timer slack controls the
513                                 accuracy of wake-ups triggered by
514                                 timers. See
515                                 <citerefentry><refentrytitle>prctl</refentrytitle><manvolnum>2</manvolnum></citerefentry>
516                                 for more information. Note that in
517                                 contrast to most other time span
518                                 definitions this parameter takes an
519                                 integer value in nano-seconds and does
520                                 not understand any other
521                                 units.</para></listitem>
522                         </varlistentry>
523
524                         <varlistentry>
525                                 <term><varname>LimitCPU=</varname></term>
526                                 <term><varname>LimitFSIZE=</varname></term>
527                                 <term><varname>LimitDATA=</varname></term>
528                                 <term><varname>LimitSTACK=</varname></term>
529                                 <term><varname>LimitCORE=</varname></term>
530                                 <term><varname>LimitRSS=</varname></term>
531                                 <term><varname>LimitNOFILE=</varname></term>
532                                 <term><varname>LimitAS=</varname></term>
533                                 <term><varname>LimitNPROC=</varname></term>
534                                 <term><varname>LimitMEMLOCK=</varname></term>
535                                 <term><varname>LimitLOCKS=</varname></term>
536                                 <term><varname>LimitSIGPENDING=</varname></term>
537                                 <term><varname>LimitMSGQUEUE=</varname></term>
538                                 <term><varname>LimitNICE=</varname></term>
539                                 <term><varname>LimitRTPRIO=</varname></term>
540                                 <term><varname>LimitRTTIME=</varname></term>
541                                 <listitem><para>These settings control
542                                 various resource limits for executed
543                                 processes. See
544                                 <citerefentry><refentrytitle>setrlimit</refentrytitle><manvolnum>2</manvolnum></citerefentry>
545                                 for details.</para></listitem>
546                         </varlistentry>
547
548                         <varlistentry>
549                                 <term><varname>PAMName=</varname></term>
550                                 <listitem><para>Sets the PAM service
551                                 name to set up a session as. If set
552                                 the executed process will be
553                                 registered as a PAM session under the
554                                 specified service name. This is only
555                                 useful in conjunction with the
556                                 <varname>User=</varname> setting. If
557                                 not set no PAM session will be opened
558                                 for the executed processes. See
559                                 <citerefentry><refentrytitle>pam</refentrytitle><manvolnum>8</manvolnum></citerefentry>
560                                 for details.</para></listitem>
561                         </varlistentry>
562
563                         <varlistentry>
564                                 <term><varname>TCPWrapName=</varname></term>
565                                 <listitem><para>If this is a
566                                 socket-activated service this sets the
567                                 tcpwrap service name to check the
568                                 permission for the current connection
569                                 with. This is only useful in
570                                 conjunction with socket-activated
571                                 services, and stream sockets (TCP) in
572                                 particular. It has no effect on other
573                                 socket types (e.g. datagram/UDP) and on processes
574                                 unrelated to socket-based
575                                 activation. If the tcpwrap
576                                 verification fails daemon start-up
577                                 will fail and the connection is
578                                 terminated. See
579                                 <citerefentry><refentrytitle>tcpd</refentrytitle><manvolnum>8</manvolnum></citerefentry>
580                                 for details.</para></listitem>
581                         </varlistentry>
582
583                         <varlistentry>
584                                 <term><varname>Capabilities=</varname></term>
585                                 <listitem><para>Controls the
586                                 <citerefentry><refentrytitle>capabilities</refentrytitle><manvolnum>7</manvolnum></citerefentry>
587                                 set for the executed process. Take a
588                                 capability string as described in
589                                 <citerefentry><refentrytitle>cap_from_text</refentrytitle><manvolnum>3</manvolnum></citerefentry>.
590                                 Note that this capability set is
591                                 usually influenced by the capabilities
592                                 attached to the executed
593                                 file.</para></listitem>
594                         </varlistentry>
595
596                         <varlistentry>
597                                 <term><varname>SecureBits=</varname></term>
598                                 <listitem><para>Controls the secure
599                                 bits set for the executed process. See
600                                 <citerefentry><refentrytitle>capabilities</refentrytitle><manvolnum>7</manvolnum></citerefentry>
601                                 for details. Takes a list of strings:
602                                 <option>keep-caps</option>,
603                                 <option>keep-caps-locked</option>,
604                                 <option>no-setuid-fixup</option>,
605                                 <option>no-setuid-fixup-locked</option>,
606                                 <option>no-setuid-noroot</option> and/or
607                                 <option>no-setuid-noroot-locked</option>.
608                                 </para></listitem>
609                         </varlistentry>
610
611                         <varlistentry>
612                                 <term><varname>CapabilityBoundingSetDrop=</varname></term>
613
614                                 <listitem><para>Controls the
615                                 capability bounding set drop set for
616                                 the executed process. See
617                                 <citerefentry><refentrytitle>capabilities</refentrytitle><manvolnum>7</manvolnum></citerefentry>
618                                 for details. Takes a list of
619                                 capability names as read by
620                                 <citerefentry><refentrytitle>cap_from_name</refentrytitle><manvolnum>3</manvolnum></citerefentry>.
621                                 </para></listitem>
622                         </varlistentry>
623
624                         <varlistentry>
625                                 <term><varname>ControlGroup=</varname></term>
626
627                                 <listitem><para>Controls the control
628                                 groups the executed processes shall be
629                                 made members of. Takes a
630                                 space-separated list of cgroup
631                                 identifiers. A cgroup identifier has a
632                                 format like
633                                 <filename>cpu:/foo/bar</filename>,
634                                 where "cpu" identifies the kernel
635                                 control group controller used, and
636                                 <filename>/foo/bar</filename> is the
637                                 control group path. The controller name
638                                 and ":" may be omitted in which case
639                                 the named systemd control group
640                                 hierarchy is implied. Alternatively,
641                                 the path and ":" may be omitted, in
642                                 which case the default control group
643                                 path for this unit is implied. This
644                                 option may be used to place executed
645                                 processes in arbitrary groups in
646                                 arbitrary hierachies -- which can be
647                                 configured externally with additional execution limits. By default
648                                 systemd will place all executed
649                                 processes in separate per-unit control
650                                 groups (named after the unit) in the
651                                 systemd named hierarchy. Since every
652                                 process can be in one group per
653                                 hierarchy only overriding the control group
654                                 path in the named systemd hierarchy
655                                 will disable automatic placement in
656                                 the default group. For details about control
657                                 groups see <ulink
658                                 url="http://www.kernel.org/doc/Documentation/cgroups/cgroups.txt">cgroups.txt</ulink>.</para></listitem>
659                         </varlistentry>
660
661                         <varlistentry>
662                                 <term><varname>ReadWriteDirectories=</varname></term>
663                                 <term><varname>ReadOnlyDirectories=</varname></term>
664                                 <term><varname>InaccessibleDirectories=</varname></term>
665
666                                 <listitem><para>Sets up a new
667                                 file-system name space for executed
668                                 processes. These options may be used
669                                 to limit access a process might have
670                                 to the main file-system
671                                 hierarchy. Each setting takes a
672                                 space-separated list of absolute
673                                 directory paths. Directories listed in
674                                 <varname>ReadWriteDirectories=</varname>
675                                 are accessible from within the
676                                 namespace with the same access rights
677                                 as from outside. Directories listed in
678                                 <varname>ReadOnlyDirectories=</varname>
679                                 are accessible for reading only,
680                                 writing will be refused even if the
681                                 usual file access controls would
682                                 permit this. Directories listed in
683                                 <varname>InaccessibleDirectories=</varname>
684                                 will be made inaccesible for processes
685                                 inside the namespace. Note that
686                                 restricting access with these options
687                                 does not extend to submounts of a
688                                 directory. You must list submounts
689                                 separately in these settings to
690                                 ensure the same limited access. These
691                                 options may be specified more than
692                                 once in which case all directories
693                                 listed will have limited access from
694                                 within the
695                                 namespace.</para></listitem>
696                         </varlistentry>
697
698                         <varlistentry>
699                                 <term><varname>PrivateTmp=</varname></term>
700
701                                 <listitem><para>Takes a boolean
702                                 argument. If true sets up a new
703                                 namespace for the executed processes
704                                 and mounts a private
705                                 <filename>/tmp</filename> directory
706                                 inside it, that is not shared by
707                                 processes outside of the
708                                 namespace. This is useful to secure
709                                 access to temporary files of the
710                                 process, but makes sharing between
711                                 processes via
712                                 <filename>/tmp</filename>
713                                 impossible. Defaults to false.</para></listitem>
714                         </varlistentry>
715
716                         <varlistentry>
717                                 <term><varname>MountFlags=</varname></term>
718
719                                 <listitem><para>Takes a mount
720                                 propagation flag:
721                                 <option>shared</option>,
722                                 <option>slave</option> or
723                                 <option>private</option>, which
724                                 control whether namespaces set up with
725                                 <varname>ReadWriteDirectories=</varname>,
726                                 <varname>ReadOnlyDirectories=</varname>
727                                 and
728                                 <varname>InaccessibleDirectories=</varname>
729                                 receive or propagate new mounts
730                                 from/to the main namespace. See
731                                 <citerefentry><refentrytitle>mount</refentrytitle><manvolnum>1</manvolnum></citerefentry>
732                                 for details. Defaults to
733                                 <option>shared</option>, i.e. the new
734                                 namespace will both receive new mount
735                                 points from the main namespace as well
736                                 as propagate new mounts to
737                                 it.</para></listitem>
738                         </varlistentry>
739
740                         <varlistentry>
741                                 <term><varname>UtmpIdentifier=</varname></term>
742
743                                 <listitem><para>Takes a a four
744                                 character identifier string for an
745                                 utmp/wtmp entry for this service. This
746                                 should only be set for services such
747                                 as <command>getty</command>
748                                 implementations where utmp/wtmp
749                                 entries must be created and cleared
750                                 before and after execution. If the
751                                 configured string is longer than four
752                                 characters it is truncated and the
753                                 terminal four characters are
754                                 used. This setting interprets %I style
755                                 string replacements. This setting is
756                                 unset by default, i.e. no utmp/wtmp
757                                 entries are created or cleaned up for
758                                 this service.</para></listitem>
759                         </varlistentry>
760
761                 </variablelist>
762         </refsect1>
763
764         <refsect1>
765                   <title>See Also</title>
766                   <para>
767                           <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
768                           <citerefentry><refentrytitle>systemctl</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
769                           <citerefentry><refentrytitle>systemd.unit</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
770                           <citerefentry><refentrytitle>systemd.service</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
771                           <citerefentry><refentrytitle>systemd.socket</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
772                           <citerefentry><refentrytitle>systemd.swap</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
773                           <citerefentry><refentrytitle>systemd.mount</refentrytitle><manvolnum>5</manvolnum></citerefentry>
774                   </para>
775         </refsect1>
776
777 </refentry>