1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
|
<?xml version='1.0'?> <!--*-nxml-*-->
<!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.5//EN"
"http://www.oasis-open.org/docbook/xml/4.5/docbookx.dtd">
<!-- SPDX-License-Identifier: LGPL-2.1-or-later -->
<refentry id="sd_device_get_syspath"
xmlns:xi="http://www.w3.org/2001/XInclude">
<refentryinfo>
<title>sd_device_get_syspath</title>
<productname>systemd</productname>
</refentryinfo>
<refmeta>
<refentrytitle>sd_device_get_syspath</refentrytitle>
<manvolnum>3</manvolnum>
</refmeta>
<refnamediv>
<refname>sd_device_get_syspath</refname>
<refname>sd_device_get_devpath</refname>
<refname>sd_device_get_sysname</refname>
<refname>sd_device_get_sysnum</refname>
<refname>sd_device_get_subsystem</refname>
<refname>sd_device_get_driver_subsystem</refname>
<refname>sd_device_get_devtype</refname>
<refname>sd_device_get_devname</refname>
<refname>sd_device_get_devnum</refname>
<refname>sd_device_get_ifindex</refname>
<refname>sd_device_get_driver</refname>
<refname>sd_device_get_diskseq</refname>
<refname>sd_device_get_device_id</refname>
<refpurpose>Returns various fields of device objects</refpurpose>
</refnamediv>
<refsynopsisdiv>
<funcsynopsis>
<funcsynopsisinfo>#include <systemd/sd-device.h></funcsynopsisinfo>
<funcprototype>
<funcdef>int <function>sd_device_get_syspath</function></funcdef>
<paramdef>sd_device *<parameter>device</parameter></paramdef>
<paramdef>const char **<parameter>ret</parameter></paramdef>
</funcprototype>
<funcprototype>
<funcdef>int <function>sd_device_get_devpath</function></funcdef>
<paramdef>sd_device *<parameter>device</parameter></paramdef>
<paramdef>const char **<parameter>ret</parameter></paramdef>
</funcprototype>
<funcprototype>
<funcdef>int <function>sd_device_get_sysname</function></funcdef>
<paramdef>sd_device *<parameter>device</parameter></paramdef>
<paramdef>const char **<parameter>ret</parameter></paramdef>
</funcprototype>
<funcprototype>
<funcdef>int <function>sd_device_get_sysnum</function></funcdef>
<paramdef>sd_device *<parameter>device</parameter></paramdef>
<paramdef>const char **<parameter>ret</parameter></paramdef>
</funcprototype>
<funcprototype>
<funcdef>int <function>sd_device_get_subsystem</function></funcdef>
<paramdef>sd_device *<parameter>device</parameter></paramdef>
<paramdef>const char **<parameter>ret</parameter></paramdef>
</funcprototype>
<funcprototype>
<funcdef>int <function>sd_device_get_driver_subsystem</function></funcdef>
<paramdef>sd_device *<parameter>device</parameter></paramdef>
<paramdef>const char **<parameter>ret</parameter></paramdef>
</funcprototype>
<funcprototype>
<funcdef>int <function>sd_device_get_devtype</function></funcdef>
<paramdef>sd_device *<parameter>device</parameter></paramdef>
<paramdef>const char **<parameter>ret</parameter></paramdef>
</funcprototype>
<funcprototype>
<funcdef>int <function>sd_device_get_devname</function></funcdef>
<paramdef>sd_device *<parameter>device</parameter></paramdef>
<paramdef>const char **<parameter>ret</parameter></paramdef>
</funcprototype>
<funcprototype>
<funcdef>int <function>sd_device_get_devnum</function></funcdef>
<paramdef>sd_device *<parameter>device</parameter></paramdef>
<paramdef>dev_t *<parameter>ret</parameter></paramdef>
</funcprototype>
<funcprototype>
<funcdef>int <function>sd_device_get_ifindex</function></funcdef>
<paramdef>sd_device *<parameter>device</parameter></paramdef>
<paramdef>int *<parameter>ret</parameter></paramdef>
</funcprototype>
<funcprototype>
<funcdef>int <function>sd_device_get_driver</function></funcdef>
<paramdef>sd_device *<parameter>device</parameter></paramdef>
<paramdef>const char **<parameter>ret</parameter></paramdef>
</funcprototype>
<funcprototype>
<funcdef>int <function>sd_device_get_diskseq</function></funcdef>
<paramdef>sd_device *<parameter>device</parameter></paramdef>
<paramdef>uint64_t *<parameter>ret</parameter></paramdef>
</funcprototype>
<funcprototype>
<funcdef>int <function>sd_device_get_device_id</function></funcdef>
<paramdef>sd_device *<parameter>device</parameter></paramdef>
<paramdef>const char **<parameter>ret</parameter></paramdef>
</funcprototype>
</funcsynopsis>
</refsynopsisdiv>
<refsect1>
<title>Description</title>
<para><function>sd_device_get_syspath()</function> returns the sysfs path of the specified device record,
including the <filename>/sys</filename> prefix. Example: <filename>/sys/devices/virtual/tty/tty7</filename></para>
<para><function>sd_device_get_devpath()</function> returns the sysfs path of the specified device record,
excluding the <filename>/sys</filename> prefix. Example: <filename>/devices/virtual/tty/tty7</filename></para>
<para><function>sd_device_get_sysname()</function> returns the sysfs name of the specified device record,
i.e. the last component of the sysfs path. Example: <literal>tty7</literal> for the device
<filename>/sys/devices/virtual/tty/tty7</filename></para>
<para><function>sd_device_get_sysnum()</function> returns the sysfs device number of the specified device
record, i.e. the numeric suffix of the last component of the sysfs path. Example: <literal>7</literal>
for the device <filename>/sys/devices/virtual/tty/tty7</filename></para>
<para><function>sd_device_get_subsystem()</function> returns the kernel subsystem of the specified device
record. This is a short string fitting into a filename, and thus does not contain a slash and cannot be
empty. Example: <literal>tty</literal>, <literal>block</literal> or <literal>net</literal>.</para>
<para><function>sd_device_get_driver_subsystem()</function> returns the connected bus type of the devices
loaded by the specified driver device record. For example, when <literal>iwlwifi</literal> driver device
is specified, which is used by the wireless network interfaces connected to PCI bus, this function returns
<literal>pci</literal>. This function only succeeds when <function>sd_device_get_subsystem()</function>
returns <literal>drivers</literal>. Example: <literal>pci</literal>, <literal>i2c</literal>, or
<literal>hid</literal>.</para>
<para><function>sd_device_get_devtype()</function> returns the device type of the specified device
record, if the subsystem manages multiple types of devices. Example: for devices of the
<literal>block</literal> subsystem this can be <literal>disk</literal> or <literal>partition</literal>
</para>
<para><function>sd_device_get_devname()</function> returns the device node path of the specified device
record if the device has a device node. Example: for <filename>/sys/devices/virtual/tty/tty7</filename>
the string <filename>/dev/tty7</filename> is typically returned.</para>
<para><function>sd_device_get_devnum()</function> returns the device node major/minor
(i.e. <type>dev_t</type>) of the specified device record if the device has a device node (i.e. the one
returned by <function>sd_device_get_devname()</function>). For devices belonging to the
<literal>block</literal> subsystem this refers to a block device node, in all other cases to a character
device node. Example: for the <filename>/sys/devices/virtual/tty/tty7</filename> device this typically
returns the device number with major/minor <literal>4:7</literal>.</para>
<para><function>sd_device_get_ifindex()</function> returns the network interface index of the specified
device record, if the device encapsulates a network interface device, i.e. belongs to the
<literal>net</literal> subsystem. Example: the <literal>lo</literal> interface typically has interface
index 1.</para>
<para><function>sd_device_get_driver()</function> returns the kernel driver name attached to the
device. Note that the driver field is set on the devices consumed by the driver, not on the device
created by it. Example: a PCI device <filename>/sys/bus/pci/devices/0000:00:1f.6</filename> might be
attached to a driver <literal>e1000e</literal>.</para>
<para><function>sd_device_get_diskseq()</function> returns the kernel disk sequence number of the block
device. This number monotonically increases whenever a backing medium of a block device changes without
the device name changing, and is relevant for block devices encapsulating devices with changing media
(e.g. floppy or CD-ROM), or loopback block devices. Only defined for block devices, i.e. those of
subsystem <literal>block</literal>.</para>
<para><function>sd_device_get_device_id()</function> returns the short string that identifies the device
record. When the device ID obtained by the function for a specified device record is passed to
<function>sd_device_new_from_device_id()</function>, a new instance of the same device record will be
gained. When a block or character device is specified, which has corresponding device node, this returns
<literal>b</literal> or <literal>c</literal>, respectively, followed by the device node major and minor
numbers separated with a colon. Example: <literal>b259:1</literal> or <literal>c10:121</literal>. When a
network interface device is specified, this returns <literal>n</literal> followed by the interface index,
which can be obtained by <function>sd_device_get_ifindex()</function>. Example: <literal>n1</literal>.
When a device in the <literal>driver</literal> subsystem is specified, this returns
<literal>+drivers:</literal> followed by its driver subsystem and sysfs name separated with a colon.
Example: <literal>+drivers:pci:iwlwifi</literal> for a driver device record whose driver subsystem is
<literal>pci</literal> and sysfs name is <literal>iwlwifi</literal>,
When an other type of device is specified, this function returns <literal>+</literal> followed by its
subsystem and sysfs name separated with a colon. Example: <literal>+acpi:ACPI0003:00</literal>,
<literal>+input:input16</literal>, or <literal>+pci:0000:00:1f.6</literal>.</para>
</refsect1>
<refsect1>
<title>Return Value</title>
<para>On success, these calls return 0 or a positive integer. On failure, they return a negative
errno-style error code.</para>
<refsect2>
<title>Errors</title>
<para>Returned errors may indicate the following problems:</para>
<variablelist>
<varlistentry>
<term><constant>-EINVAL</constant></term>
<listitem><para>A specified parameter is invalid.</para>
<xi:include href="version-info.xml" xpointer="v251"/></listitem>
</varlistentry>
<varlistentry>
<term><constant>-ENOENT</constant></term>
<listitem><para>The requested field is not present in the device record.</para>
<xi:include href="version-info.xml" xpointer="v251"/></listitem>
</varlistentry>
</variablelist>
</refsect2>
</refsect1>
<xi:include href="libsystemd-pkgconfig.xml" />
<refsect1>
<title>History</title>
<para><function>sd_device_get_syspath()</function>,
<function>sd_device_get_devpath()</function>,
<function>sd_device_get_sysname()</function>,
<function>sd_device_get_sysnum()</function>,
<function>sd_device_get_subsystem()</function>,
<function>sd_device_get_devtype()</function>,
<function>sd_device_get_devname()</function>,
<function>sd_device_get_devnum()</function>,
<function>sd_device_get_ifindex()</function>,
<function>sd_device_get_driver()</function>, and
<function>sd_device_get_diskseq()</function> were added in version 251.</para>
<para><function>sd_device_get_driver_subsystem()</function> and
<function>sd_device_get_device_id()</function> were added in version 257.</para>
</refsect1>
<refsect1>
<title>See Also</title>
<para>
<citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>
</para>
</refsect1>
</refentry>
|
