1# syspara Module<a name="EN-US_TOPIC_0000001063362360"></a> 2 3## Introduction<a name="section381564832813"></a> 4 5This module provides an easy-to-use key-value pair access interface for system services to configure service functions based on their own system parameters. The following figure shows the basic primitives used to access and operate system parameters. 6 7**Figure 1** Operation primitives for system parameters<a name="fig1976004014480"></a> 8 9 10**Table 1** Description of operation primitives 11 12<a name="table899071145116"></a> 13<table><thead align="left"><tr id="row699014115513"><th class="cellrowborder" valign="top" width="15.97%" id="mcps1.2.3.1.1"><p id="p9990111195119"><a name="p9990111195119"></a><a name="p9990111195119"></a>Primitive</p> 14</th> 15<th class="cellrowborder" valign="top" width="84.03%" id="mcps1.2.3.1.2"><p id="p5990614518"><a name="p5990614518"></a><a name="p5990614518"></a>Description</p> 16</th> 17</tr> 18</thead> 19<tbody><tr id="row1699011113511"><td class="cellrowborder" valign="top" width="15.97%" headers="mcps1.2.3.1.1 "><p id="p099071175116"><a name="p099071175116"></a><a name="p099071175116"></a>get</p> 20</td> 21<td class="cellrowborder" valign="top" width="84.03%" headers="mcps1.2.3.1.2 "><p id="p199021165116"><a name="p199021165116"></a><a name="p199021165116"></a>Obtains the value of a system parameter.</p> 22</td> 23</tr> 24<tr id="row1299019117513"><td class="cellrowborder" valign="top" width="15.97%" headers="mcps1.2.3.1.1 "><p id="p159901918510"><a name="p159901918510"></a><a name="p159901918510"></a>set</p> 25</td> 26<td class="cellrowborder" valign="top" width="84.03%" headers="mcps1.2.3.1.2 "><p id="p1990181115112"><a name="p1990181115112"></a><a name="p1990181115112"></a>Sets the value of a system parameter.</p> 27</td> 28</tr> 29<tr id="row19901812519"><td class="cellrowborder" valign="top" width="15.97%" headers="mcps1.2.3.1.1 "><p id="p1999014105117"><a name="p1999014105117"></a><a name="p1999014105117"></a>wait</p> 30</td> 31<td class="cellrowborder" valign="top" width="84.03%" headers="mcps1.2.3.1.2 "><p id="p399010135114"><a name="p399010135114"></a><a name="p399010135114"></a>Waits for value change of a system parameter synchronously.</p> 32</td> 33</tr> 34<tr id="row1990161115119"><td class="cellrowborder" valign="top" width="15.97%" headers="mcps1.2.3.1.1 "><p id="p16990515518"><a name="p16990515518"></a><a name="p16990515518"></a>watch</p> 35</td> 36<td class="cellrowborder" valign="top" width="84.03%" headers="mcps1.2.3.1.2 "><p id="p49914114514"><a name="p49914114514"></a><a name="p49914114514"></a>Observes value change of a system parameter asynchronously.</p> 37</td> 38</tr> 39</tbody> 40</table> 41 42A system parameter name consists of multiple segments in dotted notation. Each segment consists of letters, digits, and underscores \(\_\). The total length cannot exceed 96 bytes. System parameter names are categorized into the following two types. 43 44**Table 2** Naming of system parameters 45 46<a name="table112542320396"></a> 47<table><thead align="left"><tr id="row14254173103914"><th class="cellrowborder" valign="top" width="16.18%" id="mcps1.2.5.1.1"><p id="p14949687392"><a name="p14949687392"></a><a name="p14949687392"></a>Type</p> 48</th> 49<th class="cellrowborder" valign="top" width="22.03%" id="mcps1.2.5.1.2"><p id="p694920810396"><a name="p694920810396"></a><a name="p694920810396"></a>Name</p> 50</th> 51<th class="cellrowborder" valign="top" width="21.16%" id="mcps1.2.5.1.3"><p id="p294910814394"><a name="p294910814394"></a><a name="p294910814394"></a>Example</p> 52</th> 53<th class="cellrowborder" valign="top" width="40.63%" id="mcps1.2.5.1.4"><p id="p139499833914"><a name="p139499833914"></a><a name="p139499833914"></a>Description</p> 54</th> 55</tr> 56</thead> 57<tbody><tr id="row925413163910"><td class="cellrowborder" valign="top" width="16.18%" headers="mcps1.2.5.1.1 "><p id="p1594948123911"><a name="p1594948123911"></a><a name="p1594948123911"></a>Parameter name</p> 58</td> 59<td class="cellrowborder" valign="top" width="22.03%" headers="mcps1.2.5.1.2 "><p id="p29497883916"><a name="p29497883916"></a><a name="p29497883916"></a>Parameter Name</p> 60</td> 61<td class="cellrowborder" valign="top" width="21.16%" headers="mcps1.2.5.1.3 "><p id="p0949128173919"><a name="p0949128173919"></a><a name="p0949128173919"></a>const.product.<strong id="b149490833912"><a name="b149490833912"></a><a name="b149490833912"></a>name</strong></p> 62</td> 63<td class="cellrowborder" valign="top" width="40.63%" headers="mcps1.2.5.1.4 "><p id="p179491489392"><a name="p179491489392"></a><a name="p179491489392"></a>Complete system parameter name. It does not end with a period (.).</p> 64</td> 65</tr> 66<tr id="row92543373919"><td class="cellrowborder" valign="top" width="16.18%" headers="mcps1.2.5.1.1 "><p id="p159496813399"><a name="p159496813399"></a><a name="p159496813399"></a>Parameter directory</p> 67</td> 68<td class="cellrowborder" valign="top" width="22.03%" headers="mcps1.2.5.1.2 "><p id="p12950118133918"><a name="p12950118133918"></a><a name="p12950118133918"></a>Parameter Directory</p> 69</td> 70<td class="cellrowborder" valign="top" width="21.16%" headers="mcps1.2.5.1.3 "><p id="p49501863913"><a name="p49501863913"></a><a name="p49501863913"></a>const.product<strong id="b4950189395"><a name="b4950189395"></a><a name="b4950189395"></a>.</strong></p> 71</td> 72<td class="cellrowborder" valign="top" width="40.63%" headers="mcps1.2.5.1.4 "><p id="p49502843912"><a name="p49502843912"></a><a name="p49502843912"></a>Name of the directory storing system parameters with the same prefix. It ends with a period (.).</p> 73</td> 74</tr> 75</tbody> 76</table> 77 78System parameters are categorized into three types. 79 80**Table 3** System parameter types 81 82<a name="table115286426391"></a> 83<table><thead align="left"><tr id="row1852954263910"><th class="cellrowborder" valign="top" width="16.6016601660166%" id="mcps1.2.4.1.1"><p id="p240948143911"><a name="p240948143911"></a><a name="p240948143911"></a>Type</p> 84</th> 85<th class="cellrowborder" valign="top" width="21.242124212421242%" id="mcps1.2.4.1.2"><p id="p8403483399"><a name="p8403483399"></a><a name="p8403483399"></a>Prefix</p> 86</th> 87<th class="cellrowborder" valign="top" width="62.15621562156216%" id="mcps1.2.4.1.3"><p id="p1540748153916"><a name="p1540748153916"></a><a name="p1540748153916"></a>Description</p> 88</th> 89</tr> 90</thead> 91<tbody><tr id="row145291642143915"><td class="cellrowborder" valign="top" width="16.6016601660166%" headers="mcps1.2.4.1.1 "><p id="p040134815392"><a name="p040134815392"></a><a name="p040134815392"></a>Constant</p> 92</td> 93<td class="cellrowborder" valign="top" width="21.242124212421242%" headers="mcps1.2.4.1.2 "><p id="p114014814391"><a name="p114014814391"></a><a name="p114014814391"></a><strong id="b16400482395"><a name="b16400482395"></a><a name="b16400482395"></a>const.</strong></p> 94</td> 95<td class="cellrowborder" valign="top" width="62.15621562156216%" headers="mcps1.2.4.1.3 "><p id="p04018486398"><a name="p04018486398"></a><a name="p04018486398"></a>Constant parameter, which will not be changed once a value is assigned. The value can contain a maximum of 4,096 bytes (including the terminator).</p> 96</td> 97</tr> 98<tr id="row452954223914"><td class="cellrowborder" valign="top" width="16.6016601660166%" headers="mcps1.2.4.1.1 "><p id="p174064843918"><a name="p174064843918"></a><a name="p174064843918"></a>Writable</p> 99</td> 100<td class="cellrowborder" valign="top" width="21.242124212421242%" headers="mcps1.2.4.1.2 "><p id="p040114873910"><a name="p040114873910"></a><a name="p040114873910"></a>Others</p> 101</td> 102<td class="cellrowborder" valign="top" width="62.15621562156216%" headers="mcps1.2.4.1.3 "><p id="p17401548203919"><a name="p17401548203919"></a><a name="p17401548203919"></a>Writable parameter, which will be lost after system restart. The value can contain a maximum of 96 bytes (including the terminator).</p> 103</td> 104</tr> 105<tr id="row125292042103912"><td class="cellrowborder" valign="top" width="16.6016601660166%" headers="mcps1.2.4.1.1 "><p id="p240154813918"><a name="p240154813918"></a><a name="p240154813918"></a>Persistent</p> 106</td> 107<td class="cellrowborder" valign="top" width="21.242124212421242%" headers="mcps1.2.4.1.2 "><p id="p1340124812396"><a name="p1340124812396"></a><a name="p1340124812396"></a><strong id="b74094893920"><a name="b74094893920"></a><a name="b74094893920"></a>persist.</strong></p> 108</td> 109<td class="cellrowborder" valign="top" width="62.15621562156216%" headers="mcps1.2.4.1.3 "><p id="p124011485394"><a name="p124011485394"></a><a name="p124011485394"></a>Writable and persistent parameter, which will not be lost after system restart. The value can contain a maximum of 96 bytes (including the terminator).</p> 110</td> 111</tr> 112</tbody> 113</table> 114 115The naming format of system parameters is as follows: \[**const**|**persist**\].**$sub\_system**.**$desc**. 116 117**$sub\_system** is the name of the subsystem or module. 118 119**$desc** indicates the description of a system parameter. The description can contain multiple segments in dotted notation. 120 121## System Parameter Definition Rules<a name="section431671411293"></a> 122 123Each subsystem defines the system parameters of its own modules, including the system parameter name, default value, and access permission information. 124 125### System Parameter Value Definition File<a name="section885018321291"></a> 126 127The system parameter value definition file ends with the **.para** extension. An example of the file format is as follows: 128 129``` 130# This is comment 131const.product.name=OHOS-PRODUCT 132const.os.version.api=26 133const.telephony.enable=false|true 134 135const.test.withblank=My Value 136``` 137 138Note: System parameter values do not support comments and line breaks. 139 140``` 141# Not supported 142const.test.withcomment=MyValue # This should be ommitted 143# Not supported 144const.test.multiline="This is a multiline parameter. 145Line2 value. 146Last line." 147``` 148 149You must use a complete system parameter command when assigning a value for a system parameter. The following table describes the value assignment modes. 150 151**Table 4** Value assignment modes 152 153<a name="table52741681265"></a> 154<table><thead align="left"><tr id="row127520817617"><th class="cellrowborder" valign="top" width="12.221222122212222%" id="mcps1.2.4.1.1"><p id="p34581418615"><a name="p34581418615"></a><a name="p34581418615"></a>Type</p> 155</th> 156<th class="cellrowborder" valign="top" width="34.41344134413441%" id="mcps1.2.4.1.2"><p id="p134517146610"><a name="p134517146610"></a><a name="p134517146610"></a>Example</p> 157</th> 158<th class="cellrowborder" valign="top" width="53.36533653365336%" id="mcps1.2.4.1.3"><p id="p15451614166"><a name="p15451614166"></a><a name="p15451614166"></a>Description</p> 159</th> 160</tr> 161</thead> 162<tbody><tr id="row1527514815619"><td class="cellrowborder" valign="top" width="12.221222122212222%" headers="mcps1.2.4.1.1 "><p id="p045181414616"><a name="p045181414616"></a><a name="p045181414616"></a>String</p> 163</td> 164<td class="cellrowborder" valign="top" width="34.41344134413441%" headers="mcps1.2.4.1.2 "><p id="p1745111415617"><a name="p1745111415617"></a><a name="p1745111415617"></a>const.product.name=OHOS-PRODUCT</p> 165</td> 166<td class="cellrowborder" valign="top" width="53.36533653365336%" headers="mcps1.2.4.1.3 "><p id="p154513142069"><a name="p154513142069"></a><a name="p154513142069"></a>Multi-line character strings and comments are not supported.</p> 167</td> 168</tr> 169<tr id="row627519814617"><td class="cellrowborder" valign="top" width="12.221222122212222%" headers="mcps1.2.4.1.1 "><p id="p5457144620"><a name="p5457144620"></a><a name="p5457144620"></a>Number</p> 170</td> 171<td class="cellrowborder" valign="top" width="34.41344134413441%" headers="mcps1.2.4.1.2 "><p id="p94519149617"><a name="p94519149617"></a><a name="p94519149617"></a>const.os.version.api=26</p> 172</td> 173<td class="cellrowborder" valign="top" width="53.36533653365336%" headers="mcps1.2.4.1.3 "><p id="p1453146614"><a name="p1453146614"></a><a name="p1453146614"></a>Numbers do not need to be enclosed in quotation marks.</p> 174</td> 175</tr> 176<tr id="row92751882069"><td class="cellrowborder" valign="top" width="12.221222122212222%" headers="mcps1.2.4.1.1 "><p id="p17457141864"><a name="p17457141864"></a><a name="p17457141864"></a>Boolean</p> 177</td> 178<td class="cellrowborder" valign="top" width="34.41344134413441%" headers="mcps1.2.4.1.2 "><p id="p945131413611"><a name="p945131413611"></a><a name="p945131413611"></a>const.telephony.enable=false</p> 179</td> 180<td class="cellrowborder" valign="top" width="53.36533653365336%" headers="mcps1.2.4.1.3 "><p id="p164551415610"><a name="p164551415610"></a><a name="p164551415610"></a>A Boolean value can be <strong id="b8188102315415"><a name="b8188102315415"></a><a name="b8188102315415"></a>0</strong>, <strong id="b64910241414"><a name="b64910241414"></a><a name="b64910241414"></a>1</strong>, <strong id="b116922684114"><a name="b116922684114"></a><a name="b116922684114"></a>false</strong>, or <strong id="b13402102744114"><a name="b13402102744114"></a><a name="b13402102744114"></a>true</strong>.</p> 181</td> 182</tr> 183</tbody> 184</table> 185 186### System Parameter DAC Definition File<a name="section1333155762915"></a> 187 188Currently, access permissions of system parameters are managed in Discretionary Access Control \(DAC\) mode. The access permission definition file ends with the **.para.dac** extension. The following is an example: 189 190``` 191const.product.="root:root:660" 192``` 193 194As shown above, we can use **parameter directory** to define the same access permission for system parameters with the same prefix. The DAC information is divided into three segments, user, group, and UGO rule information, which are separated using a semicolon \(:\). 195 196The following figure shows the structure of the UGO rule information. 197 198**Figure 2** Rule information<a name="fig929815371095"></a> 199 200 201### Installation of the System Parameter Definition File<a name="section43801513193014"></a> 202 203The **.para** and **.para.dac** files are installed in the **/etc/param/** directory. An example of the GN script is as follows: 204 205``` 206ohos_prebuilt_etc("ohos.para") { 207 source = "//base/startup/init_lite/services/etc/ohos.para" 208 part_name = "init" 209 module_install_dir = "etc/param" 210} 211 212ohos_prebuilt_etc("ohos.para.dac") { 213 source = "//base/startup/init_lite/services/etc/ohos.para.dac" 214 part_name = "init" 215 module_install_dir = "etc/param" 216} 217``` 218 219### Loading Sequence of the System Parameter Value Definition File<a name="section89971332173017"></a> 220 221The following table provides the sequence of loading system parameter value definition files. 222 223**Table 5** Sequence of loading system parameter value definition files 224 225<a name="table1799911716110"></a> 226<table><thead align="left"><tr id="row19993720112"><th class="cellrowborder" valign="top" width="16.661666166616662%" id="mcps1.2.4.1.1"><p id="p934241851112"><a name="p934241851112"></a><a name="p934241851112"></a>Type</p> 227</th> 228<th class="cellrowborder" valign="top" width="30.183018301830185%" id="mcps1.2.4.1.2"><p id="p6342018191114"><a name="p6342018191114"></a><a name="p6342018191114"></a>Directory</p> 229</th> 230<th class="cellrowborder" valign="top" width="53.15531553155315%" id="mcps1.2.4.1.3"><p id="p193421518141113"><a name="p193421518141113"></a><a name="p193421518141113"></a>Description</p> 231</th> 232</tr> 233</thead> 234<tbody><tr id="row1299987141116"><td class="cellrowborder" valign="top" width="16.661666166616662%" headers="mcps1.2.4.1.1 "><p id="p4342171816117"><a name="p4342171816117"></a><a name="p4342171816117"></a>Kernel parameters</p> 235</td> 236<td class="cellrowborder" valign="top" width="30.183018301830185%" headers="mcps1.2.4.1.2 "><p id="p19342141817113"><a name="p19342141817113"></a><a name="p19342141817113"></a>/proc/cmdline</p> 237</td> 238<td class="cellrowborder" valign="top" width="53.15531553155315%" headers="mcps1.2.4.1.3 "><p id="p7342151818115"><a name="p7342151818115"></a><a name="p7342151818115"></a>In kernel parameters, <strong id="b93436589497"><a name="b93436589497"></a><a name="b93436589497"></a>ohospara.xxx=valXXX</strong> is converted to <strong id="b5967204145020"><a name="b5967204145020"></a><a name="b5967204145020"></a>ohos.boot.xxx=valXXX</strong>.</p> 239</td> 240</tr> 241<tr id="row1899910718117"><td class="cellrowborder" valign="top" width="16.661666166616662%" headers="mcps1.2.4.1.1 "><p id="p23421818131112"><a name="p23421818131112"></a><a name="p23421818131112"></a>OS constants</p> 242</td> 243<td class="cellrowborder" valign="top" width="30.183018301830185%" headers="mcps1.2.4.1.2 "><p id="p20342161881115"><a name="p20342161881115"></a><a name="p20342161881115"></a>/system/etc/param/ohos_const/*.para</p> 244</td> 245<td class="cellrowborder" valign="top" width="53.15531553155315%" headers="mcps1.2.4.1.3 "><p id="p163421186115"><a name="p163421186115"></a><a name="p163421186115"></a>The definition file containing OS constants is preferentially loaded.</p> 246</td> 247</tr> 248<tr id="row1098101119"><td class="cellrowborder" valign="top" width="16.661666166616662%" headers="mcps1.2.4.1.1 "><p id="p14342171815115"><a name="p14342171815115"></a><a name="p14342171815115"></a>System parameters in the <strong id="b19874122065519"><a name="b19874122065519"></a><a name="b19874122065519"></a>vendor</strong> directory</p> 249</td> 250<td class="cellrowborder" valign="top" width="30.183018301830185%" headers="mcps1.2.4.1.2 "><p id="p33425183117"><a name="p33425183117"></a><a name="p33425183117"></a>/vendor/etc/param/*.para</p> 251</td> 252<td class="cellrowborder" valign="top" width="53.15531553155315%" headers="mcps1.2.4.1.3 "><p id="p9342171861112"><a name="p9342171861112"></a><a name="p9342171861112"></a>The definition file containing system parameters in the <strong id="b974219911015"><a name="b974219911015"></a><a name="b974219911015"></a>vendor</strong> directory is loaded with the secondary priority. It can overwrite the definition file containing system parameters in the <strong id="b1544125011115"><a name="b1544125011115"></a><a name="b1544125011115"></a>system</strong> directory.</p> 253</td> 254</tr> 255<tr id="row1301784115"><td class="cellrowborder" valign="top" width="16.661666166616662%" headers="mcps1.2.4.1.1 "><p id="p234241851115"><a name="p234241851115"></a><a name="p234241851115"></a>System parameters in the <strong id="b0483162515513"><a name="b0483162515513"></a><a name="b0483162515513"></a>system</strong> directory</p> 256</td> 257<td class="cellrowborder" valign="top" width="30.183018301830185%" headers="mcps1.2.4.1.2 "><p id="p123421618161111"><a name="p123421618161111"></a><a name="p123421618161111"></a>/system/etc/param/*.para</p> 258</td> 259<td class="cellrowborder" valign="top" width="53.15531553155315%" headers="mcps1.2.4.1.3 "><p id="p134351881120"><a name="p134351881120"></a><a name="p134351881120"></a>The definition file containing system parameters in the <strong id="b1769018221223"><a name="b1769018221223"></a><a name="b1769018221223"></a>system</strong> directory is last loaded. If a system parameter value already exists in the file, it will be ignored.</p> 260</td> 261</tr> 262</tbody> 263</table> 264 265## Usage of Shell Commands<a name="section2039119283111"></a> 266 267The following table describes the shell commands used to set system parameters. 268 269**Table 6** Description of shell commands 270 271<a name="table59129731519"></a> 272<table><thead align="left"><tr id="row209121710156"><th class="cellrowborder" valign="top" width="20.5%" id="mcps1.2.3.1.1"><p id="p119421012181520"><a name="p119421012181520"></a><a name="p119421012181520"></a>Command</p> 273</th> 274<th class="cellrowborder" valign="top" width="79.5%" id="mcps1.2.3.1.2"><p id="p394210128157"><a name="p394210128157"></a><a name="p394210128157"></a>Description</p> 275</th> 276</tr> 277</thead> 278<tbody><tr id="row169122781510"><td class="cellrowborder" valign="top" width="20.5%" headers="mcps1.2.3.1.1 "><p id="p6942112161517"><a name="p6942112161517"></a><a name="p6942112161517"></a>param get [<strong id="b1942161281515"><a name="b1942161281515"></a><a name="b1942161281515"></a>key</strong>]</p> 279</td> 280<td class="cellrowborder" valign="top" width="79.5%" headers="mcps1.2.3.1.2 "><p id="p594291216151"><a name="p594291216151"></a><a name="p594291216151"></a>Obtains the system parameter value of the specified key. If no key name is specified, all system parameter values will be returned.</p> 281</td> 282</tr> 283<tr id="row17912472157"><td class="cellrowborder" valign="top" width="20.5%" headers="mcps1.2.3.1.1 "><p id="p3942191271519"><a name="p3942191271519"></a><a name="p3942191271519"></a>param set <strong id="b7942171219153"><a name="b7942171219153"></a><a name="b7942171219153"></a>key value</strong></p> 284</td> 285<td class="cellrowborder" valign="top" width="79.5%" headers="mcps1.2.3.1.2 "><p id="p1494271218159"><a name="p1494271218159"></a><a name="p1494271218159"></a>Sets the specified value for the specified key.</p> 286</td> 287</tr> 288<tr id="row0912572155"><td class="cellrowborder" valign="top" width="20.5%" headers="mcps1.2.3.1.1 "><p id="p194221231518"><a name="p194221231518"></a><a name="p194221231518"></a>param wait <strong id="b16942141213156"><a name="b16942141213156"></a><a name="b16942141213156"></a>key</strong> <strong id="b10943312161515"><a name="b10943312161515"></a><a name="b10943312161515"></a>value</strong></p> 289</td> 290<td class="cellrowborder" valign="top" width="79.5%" headers="mcps1.2.3.1.2 "><p id="p6943912161512"><a name="p6943912161512"></a><a name="p6943912161512"></a>Waits for the system parameter value of the specified key to match the specified value. Fuzzy match is supported. For example, <strong id="b79411030762"><a name="b79411030762"></a><a name="b79411030762"></a>*</strong> indicates any value, and <strong id="b162794371964"><a name="b162794371964"></a><a name="b162794371964"></a>val*</strong> indicates matching of only the first three val characters.</p> 291</td> 292</tr> 293<tr id="row1091287141516"><td class="cellrowborder" valign="top" width="20.5%" headers="mcps1.2.3.1.1 "><p id="p3943712191519"><a name="p3943712191519"></a><a name="p3943712191519"></a>param dump</p> 294</td> 295<td class="cellrowborder" valign="top" width="79.5%" headers="mcps1.2.3.1.2 "><p id="p89431212201516"><a name="p89431212201516"></a><a name="p89431212201516"></a>Displays the statistics of system parameters.</p> 296</td> 297</tr> 298</tbody> 299</table> 300 301## Available APIs<a name="section0137175692616"></a> 302 303**Table 7** APIs for the syspara module 304 305<a name="table1731550155318"></a> 306<table><thead align="left"><tr id="row4419501537"><th class="cellrowborder" valign="top" width="57.29%" id="mcps1.2.3.1.1"><p id="p54150165315"><a name="p54150165315"></a><a name="p54150165315"></a>API</p> 307</th> 308<th class="cellrowborder" valign="top" width="42.71%" id="mcps1.2.3.1.2"><p id="p941150145313"><a name="p941150145313"></a><a name="p941150145313"></a>Description</p> 309</th> 310</tr> 311</thead> 312<tbody><tr id="row34145016535"><td class="cellrowborder" valign="top" width="57.29%" headers="mcps1.2.3.1.1 "><p id="p15146174185515"><a name="p15146174185515"></a><a name="p15146174185515"></a>int GetParameter(const char* key, const char* def, char* value, unsigned int len)</p> 313</td> 314<td class="cellrowborder" valign="top" width="42.71%" headers="mcps1.2.3.1.2 "><p id="p13562171015712"><a name="p13562171015712"></a><a name="p13562171015712"></a>Obtains a system parameter.</p> 315</td> 316</tr> 317<tr id="row57882012954"><td class="cellrowborder" valign="top" width="57.29%" headers="mcps1.2.3.1.1 "><p id="p77897122517"><a name="p77897122517"></a><a name="p77897122517"></a>int SetParameter(const char* key, const char* value)</p> 318</td> 319<td class="cellrowborder" valign="top" width="42.71%" headers="mcps1.2.3.1.2 "><p id="p8150164120555"><a name="p8150164120555"></a><a name="p8150164120555"></a>Sets or updates a system parameter.</p> 320</td> 321</tr> 322<tr id="row1746172917474"><td class="cellrowborder" valign="top" width="57.29%" headers="mcps1.2.3.1.1 "><p id="p1315210414552"><a name="p1315210414552"></a><a name="p1315210414552"></a>const char* GetDeviceType(void)</p> 323</td> 324<td class="cellrowborder" valign="top" width="42.71%" headers="mcps1.2.3.1.2 "><p id="p12366194110514"><a name="p12366194110514"></a><a name="p12366194110514"></a>Obtains the device type.</p> 325</td> 326</tr> 327<tr id="row10992232154714"><td class="cellrowborder" valign="top" width="57.29%" headers="mcps1.2.3.1.1 "><p id="p19154174135517"><a name="p19154174135517"></a><a name="p19154174135517"></a>const char* GetManufacture(void)</p> 328</td> 329<td class="cellrowborder" valign="top" width="42.71%" headers="mcps1.2.3.1.2 "><p id="p191521415555"><a name="p191521415555"></a><a name="p191521415555"></a>Obtains the device manufacturer.</p> 330</td> 331</tr> 332<tr id="row137112185917"><td class="cellrowborder" valign="top" width="57.29%" headers="mcps1.2.3.1.1 "><p id="p16371201145918"><a name="p16371201145918"></a><a name="p16371201145918"></a>const char* GetBrand(void)</p> 333</td> 334<td class="cellrowborder" valign="top" width="42.71%" headers="mcps1.2.3.1.2 "><p id="p2371719599"><a name="p2371719599"></a><a name="p2371719599"></a>Obtains the device brand.</p> 335</td> 336</tr> 337<tr id="row981535875818"><td class="cellrowborder" valign="top" width="57.29%" headers="mcps1.2.3.1.1 "><p id="p18151586589"><a name="p18151586589"></a><a name="p18151586589"></a>const char* GetMarketName(void)</p> 338</td> 339<td class="cellrowborder" valign="top" width="42.71%" headers="mcps1.2.3.1.2 "><p id="p1081545865810"><a name="p1081545865810"></a><a name="p1081545865810"></a>Obtains the device marketing name.</p> 340</td> 341</tr> 342<tr id="row45019563583"><td class="cellrowborder" valign="top" width="57.29%" headers="mcps1.2.3.1.1 "><p id="p3501195617581"><a name="p3501195617581"></a><a name="p3501195617581"></a>const char* GetProductSeries(void)</p> 343</td> 344<td class="cellrowborder" valign="top" width="42.71%" headers="mcps1.2.3.1.2 "><p id="p65011156165811"><a name="p65011156165811"></a><a name="p65011156165811"></a>Obtains the device series name.</p> 345</td> 346</tr> 347<tr id="row732525410585"><td class="cellrowborder" valign="top" width="57.29%" headers="mcps1.2.3.1.1 "><p id="p10325125465819"><a name="p10325125465819"></a><a name="p10325125465819"></a>const char* GetProductModel(void)</p> 348</td> 349<td class="cellrowborder" valign="top" width="42.71%" headers="mcps1.2.3.1.2 "><p id="p332565412582"><a name="p332565412582"></a><a name="p332565412582"></a>Obtains the device authentication model.</p> 350</td> 351</tr> 352<tr id="row5746145116588"><td class="cellrowborder" valign="top" width="57.29%" headers="mcps1.2.3.1.1 "><p id="p20746145145812"><a name="p20746145145812"></a><a name="p20746145145812"></a>const char* GetSoftwareModel(void)</p> 353</td> 354<td class="cellrowborder" valign="top" width="42.71%" headers="mcps1.2.3.1.2 "><p id="p14746175165810"><a name="p14746175165810"></a><a name="p14746175165810"></a>Obtains the device software model.</p> 355</td> 356</tr> 357<tr id="row536404914589"><td class="cellrowborder" valign="top" width="57.29%" headers="mcps1.2.3.1.1 "><p id="p1364749135819"><a name="p1364749135819"></a><a name="p1364749135819"></a>const char* GetHardwareModel(void)</p> 358</td> 359<td class="cellrowborder" valign="top" width="42.71%" headers="mcps1.2.3.1.2 "><p id="p1536424935819"><a name="p1536424935819"></a><a name="p1536424935819"></a>Obtains the device hardware model.</p> 360</td> 361</tr> 362<tr id="row453414616584"><td class="cellrowborder" valign="top" width="57.29%" headers="mcps1.2.3.1.1 "><p id="p15534164685817"><a name="p15534164685817"></a><a name="p15534164685817"></a>const char* GetHardwareProfile(void)</p> 363</td> 364<td class="cellrowborder" valign="top" width="42.71%" headers="mcps1.2.3.1.2 "><p id="p15534154619588"><a name="p15534154619588"></a><a name="p15534154619588"></a>Obtains the device hardware profile.</p> 365</td> 366</tr> 367<tr id="row3279655002"><td class="cellrowborder" valign="top" width="57.29%" headers="mcps1.2.3.1.1 "><p id="p112791755204"><a name="p112791755204"></a><a name="p112791755204"></a>const char* GetSerial(void)</p> 368</td> 369<td class="cellrowborder" valign="top" width="42.71%" headers="mcps1.2.3.1.2 "><p id="p1827910551901"><a name="p1827910551901"></a><a name="p1827910551901"></a>Obtains the device serial number (SN).</p> 370</td> 371</tr> 372<tr id="row101032053602"><td class="cellrowborder" valign="top" width="57.29%" headers="mcps1.2.3.1.1 "><p id="p810395319016"><a name="p810395319016"></a><a name="p810395319016"></a>const char* GetOSFullName(void)</p> 373</td> 374<td class="cellrowborder" valign="top" width="42.71%" headers="mcps1.2.3.1.2 "><p id="p181037531301"><a name="p181037531301"></a><a name="p181037531301"></a>Obtains the operating system name.</p> 375</td> 376</tr> 377<tr id="row081175112010"><td class="cellrowborder" valign="top" width="57.29%" headers="mcps1.2.3.1.1 "><p id="p13821151707"><a name="p13821151707"></a><a name="p13821151707"></a>const char* GetDisplayVersion(void)</p> 378</td> 379<td class="cellrowborder" valign="top" width="42.71%" headers="mcps1.2.3.1.2 "><p id="p582251708"><a name="p582251708"></a><a name="p582251708"></a>Obtains the software version visible to users.</p> 380</td> 381</tr> 382<tr id="row19112249108"><td class="cellrowborder" valign="top" width="57.29%" headers="mcps1.2.3.1.1 "><p id="p1411224911016"><a name="p1411224911016"></a><a name="p1411224911016"></a>const char* GetBootloaderVersion(void)</p> 383</td> 384<td class="cellrowborder" valign="top" width="42.71%" headers="mcps1.2.3.1.2 "><p id="p11122497014"><a name="p11122497014"></a><a name="p11122497014"></a>Obtains the bootloader version of this device.</p> 385</td> 386</tr> 387<tr id="row138384461706"><td class="cellrowborder" valign="top" width="57.29%" headers="mcps1.2.3.1.1 "><p id="p20839194620019"><a name="p20839194620019"></a><a name="p20839194620019"></a>const char* GetSecurityPatchTag(void)</p> 388</td> 389<td class="cellrowborder" valign="top" width="42.71%" headers="mcps1.2.3.1.2 "><p id="p118393469018"><a name="p118393469018"></a><a name="p118393469018"></a>Obtains the security patch tag.</p> 390</td> 391</tr> 392<tr id="row58521914120"><td class="cellrowborder" valign="top" width="57.29%" headers="mcps1.2.3.1.1 "><p id="p48527149215"><a name="p48527149215"></a><a name="p48527149215"></a>const char* GetAbiList(void)</p> 393</td> 394<td class="cellrowborder" valign="top" width="42.71%" headers="mcps1.2.3.1.2 "><p id="p8852114628"><a name="p8852114628"></a><a name="p8852114628"></a>Obtains the list of application binary interfaces (ABIs) supported on this device.</p> 395</td> 396</tr> 397<tr id="row394071216210"><td class="cellrowborder" valign="top" width="57.29%" headers="mcps1.2.3.1.1 "><p id="p6140142115818"><a name="p6140142115818"></a><a name="p6140142115818"></a>int GetSdkApiVersion(void)</p> 398</td> 399<td class="cellrowborder" valign="top" width="42.71%" headers="mcps1.2.3.1.2 "><p id="p18940171215214"><a name="p18940171215214"></a><a name="p18940171215214"></a>Obtains the SDK API version that matches the current system software.</p> 400</td> 401</tr> 402<tr id="row138205101425"><td class="cellrowborder" valign="top" width="57.29%" headers="mcps1.2.3.1.1 "><p id="p19239130582"><a name="p19239130582"></a><a name="p19239130582"></a>int GetFirstApiVersion(void)</p> 403</td> 404<td class="cellrowborder" valign="top" width="42.71%" headers="mcps1.2.3.1.2 "><p id="p3820810521"><a name="p3820810521"></a><a name="p3820810521"></a>Obtains the first SDK API version of the system software.</p> 405</td> 406</tr> 407<tr id="row156198627"><td class="cellrowborder" valign="top" width="57.29%" headers="mcps1.2.3.1.1 "><p id="p75622084212"><a name="p75622084212"></a><a name="p75622084212"></a>const char* GetIncrementalVersion(void)</p> 408</td> 409<td class="cellrowborder" valign="top" width="42.71%" headers="mcps1.2.3.1.2 "><p id="p95621087211"><a name="p95621087211"></a><a name="p95621087211"></a>Obtains the incremental version.</p> 410</td> 411</tr> 412<tr id="row138721511320"><td class="cellrowborder" valign="top" width="57.29%" headers="mcps1.2.3.1.1 "><p id="p28715156318"><a name="p28715156318"></a><a name="p28715156318"></a>const char* GetVersionId(void)</p> 413</td> 414<td class="cellrowborder" valign="top" width="42.71%" headers="mcps1.2.3.1.2 "><p id="p148761512312"><a name="p148761512312"></a><a name="p148761512312"></a>Obtains the version ID.</p> 415</td> 416</tr> 417<tr id="row18749712234"><td class="cellrowborder" valign="top" width="57.29%" headers="mcps1.2.3.1.1 "><p id="p10749912738"><a name="p10749912738"></a><a name="p10749912738"></a>const char* GetBuildType(void)</p> 418</td> 419<td class="cellrowborder" valign="top" width="42.71%" headers="mcps1.2.3.1.2 "><p id="p67491212437"><a name="p67491212437"></a><a name="p67491212437"></a>Obtains the build type.</p> 420</td> 421</tr> 422<tr id="row178451710639"><td class="cellrowborder" valign="top" width="57.29%" headers="mcps1.2.3.1.1 "><p id="p58461810136"><a name="p58461810136"></a><a name="p58461810136"></a>const char* GetBuildUser(void)</p> 423</td> 424<td class="cellrowborder" valign="top" width="42.71%" headers="mcps1.2.3.1.2 "><p id="p178466109315"><a name="p178466109315"></a><a name="p178466109315"></a>Obtains the build account user name.</p> 425</td> 426</tr> 427<tr id="row126721685315"><td class="cellrowborder" valign="top" width="57.29%" headers="mcps1.2.3.1.1 "><p id="p9673781832"><a name="p9673781832"></a><a name="p9673781832"></a>const char* GetBuildHost(void)</p> 428</td> 429<td class="cellrowborder" valign="top" width="42.71%" headers="mcps1.2.3.1.2 "><p id="p12673089315"><a name="p12673089315"></a><a name="p12673089315"></a>Obtains the build host name.</p> 430</td> 431</tr> 432<tr id="row146494315815"><td class="cellrowborder" valign="top" width="57.29%" headers="mcps1.2.3.1.1 "><p id="p565184335811"><a name="p565184335811"></a><a name="p565184335811"></a>const char* GetBuildTime(void)</p> 433</td> 434<td class="cellrowborder" valign="top" width="42.71%" headers="mcps1.2.3.1.2 "><p id="p1466114365814"><a name="p1466114365814"></a><a name="p1466114365814"></a>Obtains the build time.</p> 435</td> 436</tr> 437<tr id="row933265824817"><td class="cellrowborder" valign="top" width="57.29%" headers="mcps1.2.3.1.1 "><p id="p18200134111553"><a name="p18200134111553"></a><a name="p18200134111553"></a>const char* GetBuildRootHash(void)</p> 438</td> 439<td class="cellrowborder" valign="top" width="42.71%" headers="mcps1.2.3.1.2 "><p id="p7945171118466"><a name="p7945171118466"></a><a name="p7945171118466"></a>Obtains the buildroot hash value of this version.</p> 440</td> 441</tr> 442<tr id="row9489179195318"><td class="cellrowborder" valign="top" width="57.29%" headers="mcps1.2.3.1.1 "><p id="p8489119105313"><a name="p8489119105313"></a><a name="p8489119105313"></a>const char* GetOsReleaseType(void)</p> 443</td> 444<td class="cellrowborder" valign="top" width="42.71%" headers="mcps1.2.3.1.2 "><p id="p1510173425513"><a name="p1510173425513"></a><a name="p1510173425513"></a>Obtains the system release type.</p> 445</td> 446</tr> 447<tr id="row39251243533"><td class="cellrowborder" valign="top" width="57.29%" headers="mcps1.2.3.1.1 "><p id="p119261643535"><a name="p119261643535"></a><a name="p119261643535"></a>int GetDevUdid(char *udid, int size)</p> 448</td> 449<td class="cellrowborder" valign="top" width="42.71%" headers="mcps1.2.3.1.2 "><p id="p1292654125319"><a name="p1292654125319"></a><a name="p1292654125319"></a>Obtains the device identifier (UDID).</p> 450</td> 451</tr> 452</tbody> 453</table> 454 455## How to Use<a name="section118404913233"></a> 456 457The following is an example of using syspara. 458 459``` 460// set && get 461char key1[] = "rw.sys.version"; 462char value1[] = "10.1.0"; 463int ret = SetParameter(key1, value1); 464char valueGet1[128] = {0}; 465ret = GetParameter(key1, "version=10.1.0", valueGet1, 128); 466 467// get sysparm 468char* value1 = GetDeviceType(); 469printf("Product type =%s\n", value1); 470free(value1); 471char* value2 = GetManufacture(); 472printf("Manufacture =%s\n", value2); 473free(value2); 474char* value3 = GetBrand(); 475printf("GetBrand =%s\n", value3); 476free(value3); 477char* value4 = GetMarketName(); 478printf("MarketName =%s\n", value4); 479free(value4); 480char* value5 = GetProductSeries(); 481printf("ProductSeries =%s\n", value5); 482free(value5); 483char* value6 = GetProductModel(); 484printf("ProductModel =%s\n", value6); 485free(value6); 486char* value7 = GetSoftwareModel(); 487printf("SoftwareModel =%s\n", value7); 488free(value7); 489char* value8 = GetHardwareModel(); 490printf("HardwareModel =%s\n", value8); 491free(value8); 492char* value9 = GetHardwareProfile(); 493printf("Software profile =%s\n", value9); 494free(value9); 495char* value10 = GetSerial(); 496printf("Serial =%s\n", value10); 497free(value10); 498char* value11 = GetOSFullName(); 499printf("OS name =%s\n", value11); 500free(value11); 501char* value12 = GetDisplayVersion(); 502printf("Display version =%s\n", value12); 503free(value12); 504char* value13 = GetBootloaderVersion(); 505printf("bootloader version =%s\n", value13); 506free(value13); 507char* value14 = GetSecurityPatchTag(); 508printf("secure patch level =%s\n", value14); 509free(value14); 510char* value15 = GetAbiList(); 511printf("abi list =%s\n", value15); 512free(value15); 513int value16 = GetFirstApiVersion(); 514printf("first api level =%d\n", value16); 515free(value16); 516char* value17 = GetIncrementalVersion(); 517printf("Incremental version = %s\n", value17); 518free(value17); 519char* value18 = GetVersionId(); 520printf("formal id =%s\n", value18); 521free(value18); 522char* value19 = GetBuildType(); 523printf("build type =%s\n", value19); 524free(value19); 525char* value20 = GetBuildUser(); 526printf("build user =%s\n", value20); 527free(value20); 528char* value21 = GetBuildHost(); 529printf("Build host = %s\n", value21); 530free(value21); 531char* value22 = GetBuildTime(); 532printf("build time =%s\n", value22); 533free(value22); 534char* value23 = GetBuildRootHash(); 535printf("build root later..., %s\n", value23); 536free(value23); 537char* value24 = GetOsReleaseType(); 538printf("OS release type =%s\n", value24); 539free(value24); 540char* value25 = GetOsReleaseType(); 541printf("OS release type =%s\n", value25); 542free(value25); 543char value26[65] = {0}; 544GetDevUdid(value26, 65); 545printf("device udid =%s\n", value26); 546free(value26); 547``` 548 549
