1# 虚拟文件系统<a name="ZH-CN_TOPIC_0000001123796667"></a> 2 3- [基本概念](#section1253851143520) 4- [运行机制](#section14915913123510) 5- [开发指导](#section1759563620358) 6 - [接口说明](#section17865142133511) 7 - [开发流程](#section64113023616) 8 - [编程实例](#section236041883618) 9 10 11## 基本概念<a name="section1253851143520"></a> 12 13VFS（Virtual File System）是文件系统的虚拟层，它不是一个实际的文件系统，而是一个异构文件系统之上的软件粘合层，为用户提供统一的类Unix文件操作接口。由于不同类型的文件系统接口不统一，若系统中有多个文件系统类型，访问不同的文件系统就需要使用不同的非标准接口。而通过在系统中添加VFS层，提供统一的抽象接口，屏蔽了底层异构类型的文件系统的差异，使得访问文件系统的系统调用不用关心底层的存储介质和文件系统类型，提高开发效率。 14 15OpenHarmony内核中，VFS框架是通过在内存中的树结构来实现的，树的每个结点都是一个Vnode结构体，父子结点的关系以PathCache结构体保存。VFS最主要的两个功能是： 16 17- 查找节点。 18- 统一调用（标准）。 19 20## 运行机制<a name="section14915913123510"></a> 21 22当前，VFS层主要通过函数指针，实现对不同文件系统类型调用不同接口实现标准接口功能；通过Vnode与PathCache机制，提升路径搜索以及文件访问的性能；通过挂载点管理进行分区管理；通过FD管理进行进程间FD隔离等。下面将对这些机制进行简要说明。 23 241. 文件系统操作函数指针：VFS层通过函数指针的形式，将统一调用按照不同的文件系统类型，分发到不同文件系统中进行底层操作。各文件系统的各自实现一套Vnode操作、挂载点操作以及文件操作接口，并以函数指针结构体的形式存储于对应Vnode、挂载点、File结构体中，实现VFS层对下访问。 252. Vnode：Vnode是具体文件或目录在VFS层的抽象封装，它屏蔽了不同文件系统的差异，实现资源的统一管理。Vnode节点主要有以下几种类型： 26 27 - 挂载点：挂载具体文件系统，如/、/storage 28 - 设备节点：/dev目录下的节点，对应于一个设备，如/dev/mmcblk0 29 - 文件/目录节点：对应于具体文件系统中的文件/目录，如/bin/init 30 31 Vnode通过哈希以及LRU机制进行管理。当系统启动后，对文件或目录的访问会优先从哈希链表中查找Vnode缓存，若缓存没有命中，则并从对应文件系统中搜索目标文件或目录，创建并缓存对应的Vnode。当Vnode缓存数量达到上限时，将淘汰长时间未访问的Vnode，其中挂载点Vnode与设备节点Vnode不参与淘汰。当前系统中Vnode的规格默认为512，该规格可以通过LOSCFG\_MAX\_VNODE\_SIZE进行配置。Vnode数量过大，会造成较大的内存占用；Vnode数量过少，则会造成搜索性能下降。下图展示了Vnode的创建流程。 32 33 **图 1** Vnode创建流程<a name="fig1453197573"></a> 34  35 36 371. PathCache：PathCache是路径缓存，它通过哈希表存储，利用父节点Vnode的地址和子节点的文件名，可以从PathCache中快速查找到子节点对应的Vnode。下图展示了文件/目录的查找流程。 38 39 **图 2** 文件查找流程<a name="fig1881815597396"></a> 40  41 42 431. PageCache：PageCache是内核中文件的缓存。当前PageCache仅支持缓存二进制文件，在初次访问文件时通过mmap映射到内存中，下次再访问时，直接从PageCache中读取，可以提升对同一个文件的读写速度。另外基于PageCache可实现以文件为基底的进程间通信。 442. fd管理：Fd（File Descriptor）是描述一个打开的文件/目录的描述符。当前OpenHarmony内核中，fd总规格为896，分为三种类型： 45 46 - 普通文件描述符，系统总规格为512。 47 - Socket描述符，系统总规格为128。 48 - 消息队列描述符，系统总规格为256。 49 50 当前OpenHarmony内核中，对不同进程中的fd进行隔离，即进程只能访问本进程的fd，所有进程的fd映射到全局fd表中进行统一分配管理。进程的文件描述符最多有256个。 51 523. 挂载点管理：当前OpenHarmony内核中，对系统中所有挂载点通过链表进行统一管理。挂载点结构体中，记录了该挂载分区内的所有Vnode。当分区卸载时，会释放分区内的所有Vnode。 53 54## 开发指导<a name="section1759563620358"></a> 55 56### 接口说明<a name="section17865142133511"></a> 57 58当前文件系统支持的接口如下表所示，表格中的“×”代表对应文件系统不支持该接口。 59 60**表 1** 支持接口列表 61 62<a name="table17301515163415"></a> 63<table><thead align="left"><tr id="row1730115183416"><th class="cellrowborder" valign="top" width="22.547745225477453%" id="mcps1.2.9.1.1"><p id="p830131563412"><a name="p830131563412"></a><a name="p830131563412"></a>分类</p> 64</th> 65<th class="cellrowborder" valign="top" width="22.547745225477453%" id="mcps1.2.9.1.2"><p id="p43011512345"><a name="p43011512345"></a><a name="p43011512345"></a>接口<strong id="b197068338312"><a name="b197068338312"></a><a name="b197068338312"></a>名称</strong></p> 66</th> 67<th class="cellrowborder" valign="top" width="22.547745225477453%" id="mcps1.2.9.1.3"><p id="p1130101519342"><a name="p1130101519342"></a><a name="p1130101519342"></a>功能</p> 68</th> 69<th class="cellrowborder" valign="top" width="5.499450054994501%" id="mcps1.2.9.1.4"><p id="p107591639173415"><a name="p107591639173415"></a><a name="p107591639173415"></a>FAT</p> 70</th> 71<th class="cellrowborder" valign="top" width="5.949405059494051%" id="mcps1.2.9.1.5"><p id="p540384933412"><a name="p540384933412"></a><a name="p540384933412"></a>JFFS2</p> 72</th> 73<th class="cellrowborder" valign="top" width="6.419358064193579%" id="mcps1.2.9.1.6"><p id="p1912513588343"><a name="p1912513588343"></a><a name="p1912513588343"></a>NFS</p> 74</th> 75<th class="cellrowborder" valign="top" width="6.95930406959304%" id="mcps1.2.9.1.7"><p id="p1057755183515"><a name="p1057755183515"></a><a name="p1057755183515"></a>TMPFS</p> 76</th> 77<th class="cellrowborder" valign="top" width="7.529247075292471%" id="mcps1.2.9.1.8"><p id="p25201318183510"><a name="p25201318183510"></a><a name="p25201318183510"></a>PROCFS</p> 78</th> 79</tr> 80</thead> 81<tbody><tr id="row53018152343"><td class="cellrowborder" rowspan="16" valign="top" width="22.547745225477453%" headers="mcps1.2.9.1.1 "><p id="p151510381154"><a name="p151510381154"></a><a name="p151510381154"></a>文件操作</p> 82</td> 83<td class="cellrowborder" valign="top" width="22.547745225477453%" headers="mcps1.2.9.1.2 "><p id="p5302152348"><a name="p5302152348"></a><a name="p5302152348"></a>open</p> 84</td> 85<td class="cellrowborder" valign="top" width="22.547745225477453%" headers="mcps1.2.9.1.3 "><p id="p8301815103412"><a name="p8301815103412"></a><a name="p8301815103412"></a>打开文件</p> 86</td> 87<td class="cellrowborder" valign="top" width="5.499450054994501%" headers="mcps1.2.9.1.4 "><p id="p294710215329"><a name="p294710215329"></a><a name="p294710215329"></a>√</p> 88</td> 89<td class="cellrowborder" valign="top" width="5.949405059494051%" headers="mcps1.2.9.1.5 "><p id="p9261258325"><a name="p9261258325"></a><a name="p9261258325"></a>√</p> 90</td> 91<td class="cellrowborder" valign="top" width="6.419358064193579%" headers="mcps1.2.9.1.6 "><p id="p1531472803219"><a name="p1531472803219"></a><a name="p1531472803219"></a>√</p> 92</td> 93<td class="cellrowborder" valign="top" width="6.95930406959304%" headers="mcps1.2.9.1.7 "><p id="p1081010131337"><a name="p1081010131337"></a><a name="p1081010131337"></a>√</p> 94</td> 95<td class="cellrowborder" valign="top" width="7.529247075292471%" headers="mcps1.2.9.1.8 "><p id="p9730516133310"><a name="p9730516133310"></a><a name="p9730516133310"></a>√</p> 96</td> 97</tr> 98<tr id="row1231181593416"><td class="cellrowborder" valign="top" headers="mcps1.2.9.1.1 "><p id="p1631141515344"><a name="p1631141515344"></a><a name="p1631141515344"></a>read/pread/readv/preadv</p> 99</td> 100<td class="cellrowborder" valign="top" headers="mcps1.2.9.1.2 "><p id="p731115173413"><a name="p731115173413"></a><a name="p731115173413"></a>读取文件</p> 101</td> 102<td class="cellrowborder" valign="top" headers="mcps1.2.9.1.3 "><p id="p49398914559"><a name="p49398914559"></a><a name="p49398914559"></a>√</p> 103</td> 104<td class="cellrowborder" valign="top" headers="mcps1.2.9.1.4 "><p id="p17960592553"><a name="p17960592553"></a><a name="p17960592553"></a>√</p> 105</td> 106<td class="cellrowborder" valign="top" headers="mcps1.2.9.1.5 "><p id="p69811093556"><a name="p69811093556"></a><a name="p69811093556"></a>√</p> 107</td> 108<td class="cellrowborder" valign="top" headers="mcps1.2.9.1.6 "><p id="p1599119915554"><a name="p1599119915554"></a><a name="p1599119915554"></a>√</p> 109</td> 110<td class="cellrowborder" valign="top" headers="mcps1.2.9.1.7 "><p id="p121101016557"><a name="p121101016557"></a><a name="p121101016557"></a>√</p> 111</td> 112</tr> 113<tr id="row631215173419"><td class="cellrowborder" valign="top" headers="mcps1.2.9.1.1 "><p id="p1312013310440"><a name="p1312013310440"></a><a name="p1312013310440"></a>write/pwrite/writev/pwritev</p> 114</td> 115<td class="cellrowborder" valign="top" headers="mcps1.2.9.1.2 "><p id="p1631201513418"><a name="p1631201513418"></a><a name="p1631201513418"></a>写入文件</p> 116</td> 117<td class="cellrowborder" valign="top" headers="mcps1.2.9.1.3 "><p id="p1210121018551"><a name="p1210121018551"></a><a name="p1210121018551"></a>√</p> 118</td> 119<td class="cellrowborder" valign="top" headers="mcps1.2.9.1.4 "><p id="p1120710185512"><a name="p1120710185512"></a><a name="p1120710185512"></a>√</p> 120</td> 121<td class="cellrowborder" valign="top" headers="mcps1.2.9.1.5 "><p id="p1529510185513"><a name="p1529510185513"></a><a name="p1529510185513"></a>√</p> 122</td> 123<td class="cellrowborder" valign="top" headers="mcps1.2.9.1.6 "><p id="p133911014559"><a name="p133911014559"></a><a name="p133911014559"></a>√</p> 124</td> 125<td class="cellrowborder" valign="top" headers="mcps1.2.9.1.7 "><p id="p94881019559"><a name="p94881019559"></a><a name="p94881019559"></a>√</p> 126</td> 127</tr> 128<tr id="row13820154164814"><td class="cellrowborder" valign="top" headers="mcps1.2.9.1.1 "><p id="p1982084154815"><a name="p1982084154815"></a><a name="p1982084154815"></a>lseek</p> 129</td> 130<td class="cellrowborder" valign="top" headers="mcps1.2.9.1.2 "><p id="p18201148481"><a name="p18201148481"></a><a name="p18201148481"></a>设置文件偏移</p> 131</td> 132<td class="cellrowborder" valign="top" headers="mcps1.2.9.1.3 "><p id="p1477251395513"><a name="p1477251395513"></a><a name="p1477251395513"></a>√</p> 133</td> 134<td class="cellrowborder" valign="top" headers="mcps1.2.9.1.4 "><p id="p979119136551"><a name="p979119136551"></a><a name="p979119136551"></a>√</p> 135</td> 136<td class="cellrowborder" valign="top" headers="mcps1.2.9.1.5 "><p id="p138102013175517"><a name="p138102013175517"></a><a name="p138102013175517"></a>√</p> 137</td> 138<td class="cellrowborder" valign="top" headers="mcps1.2.9.1.6 "><p id="p482041319556"><a name="p482041319556"></a><a name="p482041319556"></a>√</p> 139</td> 140<td class="cellrowborder" valign="top" headers="mcps1.2.9.1.7 "><p id="p4667132210334"><a name="p4667132210334"></a><a name="p4667132210334"></a>×</p> 141</td> 142</tr> 143<tr id="row18311215103413"><td class="cellrowborder" valign="top" headers="mcps1.2.9.1.1 "><p id="p29893124420"><a name="p29893124420"></a><a name="p29893124420"></a>close</p> 144</td> 145<td class="cellrowborder" valign="top" headers="mcps1.2.9.1.2 "><p id="p16317151345"><a name="p16317151345"></a><a name="p16317151345"></a>关闭文件</p> 146</td> 147<td class="cellrowborder" valign="top" headers="mcps1.2.9.1.3 "><p id="p1830101311552"><a name="p1830101311552"></a><a name="p1830101311552"></a>√</p> 148</td> 149<td class="cellrowborder" valign="top" headers="mcps1.2.9.1.4 "><p id="p083916133557"><a name="p083916133557"></a><a name="p083916133557"></a>√</p> 150</td> 151<td class="cellrowborder" valign="top" headers="mcps1.2.9.1.5 "><p id="p7848141318556"><a name="p7848141318556"></a><a name="p7848141318556"></a>√</p> 152</td> 153<td class="cellrowborder" valign="top" headers="mcps1.2.9.1.6 "><p id="p98581213135515"><a name="p98581213135515"></a><a name="p98581213135515"></a>√</p> 154</td> 155<td class="cellrowborder" valign="top" headers="mcps1.2.9.1.7 "><p id="p1422632414334"><a name="p1422632414334"></a><a name="p1422632414334"></a>√</p> 156</td> 157</tr> 158<tr id="row1775494216429"><td class="cellrowborder" valign="top" headers="mcps1.2.9.1.1 "><p id="p2755144216427"><a name="p2755144216427"></a><a name="p2755144216427"></a>unlink</p> 159</td> 160<td class="cellrowborder" valign="top" headers="mcps1.2.9.1.2 "><p id="p1475534213424"><a name="p1475534213424"></a><a name="p1475534213424"></a>删除文件</p> 161</td> 162<td class="cellrowborder" valign="top" headers="mcps1.2.9.1.3 "><p id="p11868171355516"><a name="p11868171355516"></a><a name="p11868171355516"></a>√</p> 163</td> 164<td class="cellrowborder" valign="top" headers="mcps1.2.9.1.4 "><p id="p78771813175517"><a name="p78771813175517"></a><a name="p78771813175517"></a>√</p> 165</td> 166<td class="cellrowborder" valign="top" headers="mcps1.2.9.1.5 "><p id="p488641355510"><a name="p488641355510"></a><a name="p488641355510"></a>√</p> 167</td> 168<td class="cellrowborder" valign="top" headers="mcps1.2.9.1.6 "><p id="p12895121315517"><a name="p12895121315517"></a><a name="p12895121315517"></a>√</p> 169</td> 170<td class="cellrowborder" valign="top" headers="mcps1.2.9.1.7 "><p id="p51901414341"><a name="p51901414341"></a><a name="p51901414341"></a>×</p> 171</td> 172</tr> 173<tr id="row730533465319"><td class="cellrowborder" valign="top" headers="mcps1.2.9.1.1 "><p id="p134325815218"><a name="p134325815218"></a><a name="p134325815218"></a>fstat</p> 174</td> 175<td class="cellrowborder" valign="top" headers="mcps1.2.9.1.2 "><p id="p03438583528"><a name="p03438583528"></a><a name="p03438583528"></a>查询文件信息</p> 176</td> 177<td class="cellrowborder" valign="top" headers="mcps1.2.9.1.3 "><p id="p190418132555"><a name="p190418132555"></a><a name="p190418132555"></a>√</p> 178</td> 179<td class="cellrowborder" valign="top" headers="mcps1.2.9.1.4 "><p id="p109131713145518"><a name="p109131713145518"></a><a name="p109131713145518"></a>√</p> 180</td> 181<td class="cellrowborder" valign="top" headers="mcps1.2.9.1.5 "><p id="p20922161345511"><a name="p20922161345511"></a><a name="p20922161345511"></a>√</p> 182</td> 183<td class="cellrowborder" valign="top" headers="mcps1.2.9.1.6 "><p id="p129311134558"><a name="p129311134558"></a><a name="p129311134558"></a>√</p> 184</td> 185<td class="cellrowborder" valign="top" headers="mcps1.2.9.1.7 "><p id="p1634395895213"><a name="p1634395895213"></a><a name="p1634395895213"></a>√</p> 186</td> 187</tr> 188<tr id="row12854143815611"><td class="cellrowborder" valign="top" headers="mcps1.2.9.1.1 "><p id="p12854123817564"><a name="p12854123817564"></a><a name="p12854123817564"></a>fallocate</p> 189</td> 190<td class="cellrowborder" valign="top" headers="mcps1.2.9.1.2 "><p id="p158541938165619"><a name="p158541938165619"></a><a name="p158541938165619"></a>预分配大小</p> 191</td> 192<td class="cellrowborder" valign="top" headers="mcps1.2.9.1.3 "><p id="p2092312119324"><a name="p2092312119324"></a><a name="p2092312119324"></a>√</p> 193</td> 194<td class="cellrowborder" valign="top" headers="mcps1.2.9.1.4 "><p id="p58541638155611"><a name="p58541638155611"></a><a name="p58541638155611"></a>×</p> 195</td> 196<td class="cellrowborder" valign="top" headers="mcps1.2.9.1.5 "><p id="p485410387565"><a name="p485410387565"></a><a name="p485410387565"></a>×</p> 197</td> 198<td class="cellrowborder" valign="top" headers="mcps1.2.9.1.6 "><p id="p9250515446"><a name="p9250515446"></a><a name="p9250515446"></a>×</p> 199</td> 200<td class="cellrowborder" valign="top" headers="mcps1.2.9.1.7 "><p id="p12178113643319"><a name="p12178113643319"></a><a name="p12178113643319"></a>×</p> 201</td> 202</tr> 203<tr id="row231161563416"><td class="cellrowborder" valign="top" headers="mcps1.2.9.1.1 "><p id="p15311154341"><a name="p15311154341"></a><a name="p15311154341"></a>truncate</p> 204</td> 205<td class="cellrowborder" valign="top" headers="mcps1.2.9.1.2 "><p id="p73111513417"><a name="p73111513417"></a><a name="p73111513417"></a>文件截断</p> 206</td> 207<td class="cellrowborder" valign="top" headers="mcps1.2.9.1.3 "><p id="p4553163085512"><a name="p4553163085512"></a><a name="p4553163085512"></a>√</p> 208</td> 209<td class="cellrowborder" valign="top" headers="mcps1.2.9.1.4 "><p id="p155722303558"><a name="p155722303558"></a><a name="p155722303558"></a>√</p> 210</td> 211<td class="cellrowborder" valign="top" headers="mcps1.2.9.1.5 "><p id="p01250585343"><a name="p01250585343"></a><a name="p01250585343"></a>×</p> 212</td> 213<td class="cellrowborder" valign="top" headers="mcps1.2.9.1.6 "><p id="p815106143319"><a name="p815106143319"></a><a name="p815106143319"></a>√</p> 214</td> 215<td class="cellrowborder" valign="top" headers="mcps1.2.9.1.7 "><p id="p20697173810337"><a name="p20697173810337"></a><a name="p20697173810337"></a>×</p> 216</td> 217</tr> 218<tr id="row931815133419"><td class="cellrowborder" valign="top" headers="mcps1.2.9.1.1 "><p id="p63151593415"><a name="p63151593415"></a><a name="p63151593415"></a>link</p> 219</td> 220<td class="cellrowborder" valign="top" headers="mcps1.2.9.1.2 "><p id="p1631101523414"><a name="p1631101523414"></a><a name="p1631101523414"></a>创建硬链接</p> 221</td> 222<td class="cellrowborder" valign="top" headers="mcps1.2.9.1.3 "><p id="p18718522143115"><a name="p18718522143115"></a><a name="p18718522143115"></a>×</p> 223</td> 224<td class="cellrowborder" valign="top" headers="mcps1.2.9.1.4 "><p id="p1147101520321"><a name="p1147101520321"></a><a name="p1147101520321"></a>√</p> 225</td> 226<td class="cellrowborder" valign="top" headers="mcps1.2.9.1.5 "><p id="p17125185815342"><a name="p17125185815342"></a><a name="p17125185815342"></a>×</p> 227</td> 228<td class="cellrowborder" valign="top" headers="mcps1.2.9.1.6 "><p id="p1985892113312"><a name="p1985892113312"></a><a name="p1985892113312"></a>×</p> 229</td> 230<td class="cellrowborder" valign="top" headers="mcps1.2.9.1.7 "><p id="p17342840113315"><a name="p17342840113315"></a><a name="p17342840113315"></a>×</p> 231</td> 232</tr> 233<tr id="row131151523420"><td class="cellrowborder" valign="top" headers="mcps1.2.9.1.1 "><p id="p113251513342"><a name="p113251513342"></a><a name="p113251513342"></a>symlink</p> 234</td> 235<td class="cellrowborder" valign="top" headers="mcps1.2.9.1.2 "><p id="p1832215133420"><a name="p1832215133420"></a><a name="p1832215133420"></a>创建软链接</p> 236</td> 237<td class="cellrowborder" valign="top" headers="mcps1.2.9.1.3 "><p id="p5780143585510"><a name="p5780143585510"></a><a name="p5780143585510"></a>√</p> 238</td> 239<td class="cellrowborder" valign="top" headers="mcps1.2.9.1.4 "><p id="p1879183525516"><a name="p1879183525516"></a><a name="p1879183525516"></a>√</p> 240</td> 241<td class="cellrowborder" valign="top" headers="mcps1.2.9.1.5 "><p id="p412505873415"><a name="p412505873415"></a><a name="p412505873415"></a>×</p> 242</td> 243<td class="cellrowborder" valign="top" headers="mcps1.2.9.1.6 "><p id="p13207802451"><a name="p13207802451"></a><a name="p13207802451"></a>×</p> 244</td> 245<td class="cellrowborder" valign="top" headers="mcps1.2.9.1.7 "><p id="p1947920415337"><a name="p1947920415337"></a><a name="p1947920415337"></a>×</p> 246</td> 247</tr> 248<tr id="row382917545412"><td class="cellrowborder" valign="top" headers="mcps1.2.9.1.1 "><p id="p158308546414"><a name="p158308546414"></a><a name="p158308546414"></a>readlink</p> 249</td> 250<td class="cellrowborder" valign="top" headers="mcps1.2.9.1.2 "><p id="p58301454144111"><a name="p58301454144111"></a><a name="p58301454144111"></a>读取软链接</p> 251</td> 252<td class="cellrowborder" valign="top" headers="mcps1.2.9.1.3 "><p id="p14802935155512"><a name="p14802935155512"></a><a name="p14802935155512"></a>√</p> 253</td> 254<td class="cellrowborder" valign="top" headers="mcps1.2.9.1.4 "><p id="p8812193535516"><a name="p8812193535516"></a><a name="p8812193535516"></a>√</p> 255</td> 256<td class="cellrowborder" valign="top" headers="mcps1.2.9.1.5 "><p id="p68301754134120"><a name="p68301754134120"></a><a name="p68301754134120"></a>×</p> 257</td> 258<td class="cellrowborder" valign="top" headers="mcps1.2.9.1.6 "><p id="p132078004517"><a name="p132078004517"></a><a name="p132078004517"></a>×</p> 259</td> 260<td class="cellrowborder" valign="top" headers="mcps1.2.9.1.7 "><p id="p147954143315"><a name="p147954143315"></a><a name="p147954143315"></a>×</p> 261</td> 262</tr> 263<tr id="row1511111910388"><td class="cellrowborder" valign="top" headers="mcps1.2.9.1.1 "><p id="p143496410465"><a name="p143496410465"></a><a name="p143496410465"></a>dup</p> 264</td> 265<td class="cellrowborder" valign="top" headers="mcps1.2.9.1.2 "><p id="p17349942461"><a name="p17349942461"></a><a name="p17349942461"></a>复制文件句柄</p> 266</td> 267<td class="cellrowborder" valign="top" headers="mcps1.2.9.1.3 "><p id="p1299875075513"><a name="p1299875075513"></a><a name="p1299875075513"></a>√</p> 268</td> 269<td class="cellrowborder" valign="top" headers="mcps1.2.9.1.4 "><p id="p5183517557"><a name="p5183517557"></a><a name="p5183517557"></a>√</p> 270</td> 271<td class="cellrowborder" valign="top" headers="mcps1.2.9.1.5 "><p id="p133845110558"><a name="p133845110558"></a><a name="p133845110558"></a>√</p> 272</td> 273<td class="cellrowborder" valign="top" headers="mcps1.2.9.1.6 "><p id="p15488511558"><a name="p15488511558"></a><a name="p15488511558"></a>√</p> 274</td> 275<td class="cellrowborder" valign="top" headers="mcps1.2.9.1.7 "><p id="p15817510554"><a name="p15817510554"></a><a name="p15817510554"></a>√</p> 276</td> 277</tr> 278<tr id="row512919173399"><td class="cellrowborder" valign="top" headers="mcps1.2.9.1.1 "><p id="p350604555614"><a name="p350604555614"></a><a name="p350604555614"></a>fsync</p> 279</td> 280<td class="cellrowborder" valign="top" headers="mcps1.2.9.1.2 "><p id="p12506184516569"><a name="p12506184516569"></a><a name="p12506184516569"></a>文件内容刷入设备</p> 281</td> 282<td class="cellrowborder" valign="top" headers="mcps1.2.9.1.3 "><p id="p13875181213213"><a name="p13875181213213"></a><a name="p13875181213213"></a>√</p> 283</td> 284<td class="cellrowborder" valign="top" headers="mcps1.2.9.1.4 "><p id="p0506145165613"><a name="p0506145165613"></a><a name="p0506145165613"></a>×</p> 285</td> 286<td class="cellrowborder" valign="top" headers="mcps1.2.9.1.5 "><p id="p6506124555620"><a name="p6506124555620"></a><a name="p6506124555620"></a>×</p> 287</td> 288<td class="cellrowborder" valign="top" headers="mcps1.2.9.1.6 "><p id="p1925165204418"><a name="p1925165204418"></a><a name="p1925165204418"></a>×</p> 289</td> 290<td class="cellrowborder" valign="top" headers="mcps1.2.9.1.7 "><p id="p1795065310333"><a name="p1795065310333"></a><a name="p1795065310333"></a>×</p> 291</td> 292</tr> 293<tr id="row11374165313411"><td class="cellrowborder" valign="top" headers="mcps1.2.9.1.1 "><p id="p3724551105613"><a name="p3724551105613"></a><a name="p3724551105613"></a>ioctl</p> 294</td> 295<td class="cellrowborder" valign="top" headers="mcps1.2.9.1.2 "><p id="p8724165112564"><a name="p8724165112564"></a><a name="p8724165112564"></a>设备控制</p> 296</td> 297<td class="cellrowborder" valign="top" headers="mcps1.2.9.1.3 "><p id="p8724251165616"><a name="p8724251165616"></a><a name="p8724251165616"></a>×</p> 298</td> 299<td class="cellrowborder" valign="top" headers="mcps1.2.9.1.4 "><p id="p2725185119569"><a name="p2725185119569"></a><a name="p2725185119569"></a>×</p> 300</td> 301<td class="cellrowborder" valign="top" headers="mcps1.2.9.1.5 "><p id="p6725125118565"><a name="p6725125118565"></a><a name="p6725125118565"></a>×</p> 302</td> 303<td class="cellrowborder" valign="top" headers="mcps1.2.9.1.6 "><p id="p172511584419"><a name="p172511584419"></a><a name="p172511584419"></a>√</p> 304</td> 305<td class="cellrowborder" valign="top" headers="mcps1.2.9.1.7 "><p id="p795045363314"><a name="p795045363314"></a><a name="p795045363314"></a>×</p> 306</td> 307</tr> 308<tr id="row1566230193619"><td class="cellrowborder" valign="top" headers="mcps1.2.9.1.1 "><p id="p8804322192315"><a name="p8804322192315"></a><a name="p8804322192315"></a>fcntl</p> 309</td> 310<td class="cellrowborder" valign="top" headers="mcps1.2.9.1.2 "><p id="p2891723102316"><a name="p2891723102316"></a><a name="p2891723102316"></a>文件控制操作</p> 311</td> 312<td class="cellrowborder" valign="top" headers="mcps1.2.9.1.3 "><p id="p16968175595517"><a name="p16968175595517"></a><a name="p16968175595517"></a>√</p> 313</td> 314<td class="cellrowborder" valign="top" headers="mcps1.2.9.1.4 "><p id="p69788557556"><a name="p69788557556"></a><a name="p69788557556"></a>√</p> 315</td> 316<td class="cellrowborder" valign="top" headers="mcps1.2.9.1.5 "><p id="p4987135555516"><a name="p4987135555516"></a><a name="p4987135555516"></a>√</p> 317</td> 318<td class="cellrowborder" valign="top" headers="mcps1.2.9.1.6 "><p id="p1599755565514"><a name="p1599755565514"></a><a name="p1599755565514"></a>√</p> 319</td> 320<td class="cellrowborder" valign="top" headers="mcps1.2.9.1.7 "><p id="p551453173620"><a name="p551453173620"></a><a name="p551453173620"></a>√</p> 321</td> 322</tr> 323<tr id="row98781157114116"><td class="cellrowborder" rowspan="17" valign="top" width="22.547745225477453%" headers="mcps1.2.9.1.1 "><p id="p10322754163618"><a name="p10322754163618"></a><a name="p10322754163618"></a>目录操作</p> 324</td> 325<td class="cellrowborder" valign="top" width="22.547745225477453%" headers="mcps1.2.9.1.2 "><p id="p98795579417"><a name="p98795579417"></a><a name="p98795579417"></a>mkdir</p> 326</td> 327<td class="cellrowborder" valign="top" width="22.547745225477453%" headers="mcps1.2.9.1.3 "><p id="p12879757144119"><a name="p12879757144119"></a><a name="p12879757144119"></a>创建目录</p> 328</td> 329<td class="cellrowborder" valign="top" width="5.499450054994501%" headers="mcps1.2.9.1.4 "><p id="p1361756205516"><a name="p1361756205516"></a><a name="p1361756205516"></a>√</p> 330</td> 331<td class="cellrowborder" valign="top" width="5.949405059494051%" headers="mcps1.2.9.1.5 "><p id="p717956115512"><a name="p717956115512"></a><a name="p717956115512"></a>√</p> 332</td> 333<td class="cellrowborder" valign="top" width="6.419358064193579%" headers="mcps1.2.9.1.6 "><p id="p32813566552"><a name="p32813566552"></a><a name="p32813566552"></a>√</p> 334</td> 335<td class="cellrowborder" valign="top" width="6.95930406959304%" headers="mcps1.2.9.1.7 "><p id="p537115611555"><a name="p537115611555"></a><a name="p537115611555"></a>√</p> 336</td> 337<td class="cellrowborder" valign="top" width="7.529247075292471%" headers="mcps1.2.9.1.8 "><p id="p9879165719415"><a name="p9879165719415"></a><a name="p9879165719415"></a>×</p> 338</td> 339</tr> 340<tr id="row362155116544"><td class="cellrowborder" valign="top" headers="mcps1.2.9.1.1 "><p id="p166210511546"><a name="p166210511546"></a><a name="p166210511546"></a>opendir</p> 341</td> 342<td class="cellrowborder" valign="top" headers="mcps1.2.9.1.2 "><p id="p11621651135417"><a name="p11621651135417"></a><a name="p11621651135417"></a>打开目录</p> 343</td> 344<td class="cellrowborder" valign="top" headers="mcps1.2.9.1.3 "><p id="p1863161175612"><a name="p1863161175612"></a><a name="p1863161175612"></a>√</p> 345</td> 346<td class="cellrowborder" valign="top" headers="mcps1.2.9.1.4 "><p id="p16655191105612"><a name="p16655191105612"></a><a name="p16655191105612"></a>√</p> 347</td> 348<td class="cellrowborder" valign="top" headers="mcps1.2.9.1.5 "><p id="p267518118566"><a name="p267518118566"></a><a name="p267518118566"></a>√</p> 349</td> 350<td class="cellrowborder" valign="top" headers="mcps1.2.9.1.6 "><p id="p18686011561"><a name="p18686011561"></a><a name="p18686011561"></a>√</p> 351</td> 352<td class="cellrowborder" valign="top" headers="mcps1.2.9.1.7 "><p id="p369611105616"><a name="p369611105616"></a><a name="p369611105616"></a>√</p> 353</td> 354</tr> 355<tr id="row183271724212"><td class="cellrowborder" valign="top" headers="mcps1.2.9.1.1 "><p id="p23313179429"><a name="p23313179429"></a><a name="p23313179429"></a>readdir</p> 356</td> 357<td class="cellrowborder" valign="top" headers="mcps1.2.9.1.2 "><p id="p1433617124218"><a name="p1433617124218"></a><a name="p1433617124218"></a>读取目录</p> 358</td> 359<td class="cellrowborder" valign="top" headers="mcps1.2.9.1.3 "><p id="p1470631135613"><a name="p1470631135613"></a><a name="p1470631135613"></a>√</p> 360</td> 361<td class="cellrowborder" valign="top" headers="mcps1.2.9.1.4 "><p id="p0715810565"><a name="p0715810565"></a><a name="p0715810565"></a>√</p> 362</td> 363<td class="cellrowborder" valign="top" headers="mcps1.2.9.1.5 "><p id="p67251414566"><a name="p67251414566"></a><a name="p67251414566"></a>√</p> 364</td> 365<td class="cellrowborder" valign="top" headers="mcps1.2.9.1.6 "><p id="p14734511565"><a name="p14734511565"></a><a name="p14734511565"></a>√</p> 366</td> 367<td class="cellrowborder" valign="top" headers="mcps1.2.9.1.7 "><p id="p1474419165617"><a name="p1474419165617"></a><a name="p1474419165617"></a>√</p> 368</td> 369</tr> 370<tr id="row11310111512553"><td class="cellrowborder" valign="top" headers="mcps1.2.9.1.1 "><p id="p183101215155514"><a name="p183101215155514"></a><a name="p183101215155514"></a>closedir</p> 371</td> 372<td class="cellrowborder" valign="top" headers="mcps1.2.9.1.2 "><p id="p2031018155555"><a name="p2031018155555"></a><a name="p2031018155555"></a>关闭目录</p> 373</td> 374<td class="cellrowborder" valign="top" headers="mcps1.2.9.1.3 "><p id="p177544125617"><a name="p177544125617"></a><a name="p177544125617"></a>√</p> 375</td> 376<td class="cellrowborder" valign="top" headers="mcps1.2.9.1.4 "><p id="p576311175619"><a name="p576311175619"></a><a name="p576311175619"></a>√</p> 377</td> 378<td class="cellrowborder" valign="top" headers="mcps1.2.9.1.5 "><p id="p18772171115612"><a name="p18772171115612"></a><a name="p18772171115612"></a>√</p> 379</td> 380<td class="cellrowborder" valign="top" headers="mcps1.2.9.1.6 "><p id="p1978310112562"><a name="p1978310112562"></a><a name="p1978310112562"></a>√</p> 381</td> 382<td class="cellrowborder" valign="top" headers="mcps1.2.9.1.7 "><p id="p27921517569"><a name="p27921517569"></a><a name="p27921517569"></a>√</p> 383</td> 384</tr> 385<tr id="row1774355219252"><td class="cellrowborder" valign="top" headers="mcps1.2.9.1.1 "><p id="p1074365218251"><a name="p1074365218251"></a><a name="p1074365218251"></a>telldir</p> 386</td> 387<td class="cellrowborder" valign="top" headers="mcps1.2.9.1.2 "><p id="p5743125232520"><a name="p5743125232520"></a><a name="p5743125232520"></a>获取目录偏移</p> 388</td> 389<td class="cellrowborder" valign="top" headers="mcps1.2.9.1.3 "><p id="p1880251135614"><a name="p1880251135614"></a><a name="p1880251135614"></a>√</p> 390</td> 391<td class="cellrowborder" valign="top" headers="mcps1.2.9.1.4 "><p id="p681110105618"><a name="p681110105618"></a><a name="p681110105618"></a>√</p> 392</td> 393<td class="cellrowborder" valign="top" headers="mcps1.2.9.1.5 "><p id="p1682112135612"><a name="p1682112135612"></a><a name="p1682112135612"></a>√</p> 394</td> 395<td class="cellrowborder" valign="top" headers="mcps1.2.9.1.6 "><p id="p1583019165610"><a name="p1583019165610"></a><a name="p1583019165610"></a>√</p> 396</td> 397<td class="cellrowborder" valign="top" headers="mcps1.2.9.1.7 "><p id="p148397175618"><a name="p148397175618"></a><a name="p148397175618"></a>√</p> 398</td> 399</tr> 400<tr id="row463867132610"><td class="cellrowborder" valign="top" headers="mcps1.2.9.1.1 "><p id="p463919772612"><a name="p463919772612"></a><a name="p463919772612"></a>seekdir</p> 401</td> 402<td class="cellrowborder" valign="top" headers="mcps1.2.9.1.2 "><p id="p163917702620"><a name="p163917702620"></a><a name="p163917702620"></a>设置目录偏移</p> 403</td> 404<td class="cellrowborder" valign="top" headers="mcps1.2.9.1.3 "><p id="p08494113563"><a name="p08494113563"></a><a name="p08494113563"></a>√</p> 405</td> 406<td class="cellrowborder" valign="top" headers="mcps1.2.9.1.4 "><p id="p19858121175618"><a name="p19858121175618"></a><a name="p19858121175618"></a>√</p> 407</td> 408<td class="cellrowborder" valign="top" headers="mcps1.2.9.1.5 "><p id="p16867131175616"><a name="p16867131175616"></a><a name="p16867131175616"></a>√</p> 409</td> 410<td class="cellrowborder" valign="top" headers="mcps1.2.9.1.6 "><p id="p487621145618"><a name="p487621145618"></a><a name="p487621145618"></a>√</p> 411</td> 412<td class="cellrowborder" valign="top" headers="mcps1.2.9.1.7 "><p id="p1088611118566"><a name="p1088611118566"></a><a name="p1088611118566"></a>√</p> 413</td> 414</tr> 415<tr id="row1361903616456"><td class="cellrowborder" valign="top" headers="mcps1.2.9.1.1 "><p id="p186191936144513"><a name="p186191936144513"></a><a name="p186191936144513"></a>rewinddir</p> 416</td> 417<td class="cellrowborder" valign="top" headers="mcps1.2.9.1.2 "><p id="p186198365451"><a name="p186198365451"></a><a name="p186198365451"></a>重置目录偏移</p> 418</td> 419<td class="cellrowborder" valign="top" headers="mcps1.2.9.1.3 "><p id="p82717515564"><a name="p82717515564"></a><a name="p82717515564"></a>√</p> 420</td> 421<td class="cellrowborder" valign="top" headers="mcps1.2.9.1.4 "><p id="p1128175145610"><a name="p1128175145610"></a><a name="p1128175145610"></a>√</p> 422</td> 423<td class="cellrowborder" valign="top" headers="mcps1.2.9.1.5 "><p id="p729113545616"><a name="p729113545616"></a><a name="p729113545616"></a>√</p> 424</td> 425<td class="cellrowborder" valign="top" headers="mcps1.2.9.1.6 "><p id="p163003585620"><a name="p163003585620"></a><a name="p163003585620"></a>√</p> 426</td> 427<td class="cellrowborder" valign="top" headers="mcps1.2.9.1.7 "><p id="p10950175314334"><a name="p10950175314334"></a><a name="p10950175314334"></a>×</p> 428</td> 429</tr> 430<tr id="row1145016117201"><td class="cellrowborder" valign="top" headers="mcps1.2.9.1.1 "><p id="p9545171282019"><a name="p9545171282019"></a><a name="p9545171282019"></a>scandir</p> 431</td> 432<td class="cellrowborder" valign="top" headers="mcps1.2.9.1.2 "><p id="p9451131102012"><a name="p9451131102012"></a><a name="p9451131102012"></a>读取目录数据</p> 433</td> 434<td class="cellrowborder" valign="top" headers="mcps1.2.9.1.3 "><p id="p230917512566"><a name="p230917512566"></a><a name="p230917512566"></a>√</p> 435</td> 436<td class="cellrowborder" valign="top" headers="mcps1.2.9.1.4 "><p id="p1831815155615"><a name="p1831815155615"></a><a name="p1831815155615"></a>√</p> 437</td> 438<td class="cellrowborder" valign="top" headers="mcps1.2.9.1.5 "><p id="p53275555611"><a name="p53275555611"></a><a name="p53275555611"></a>√</p> 439</td> 440<td class="cellrowborder" valign="top" headers="mcps1.2.9.1.6 "><p id="p1033611512565"><a name="p1033611512565"></a><a name="p1033611512565"></a>√</p> 441</td> 442<td class="cellrowborder" valign="top" headers="mcps1.2.9.1.7 "><p id="p345131118206"><a name="p345131118206"></a><a name="p345131118206"></a>√</p> 443</td> 444</tr> 445<tr id="row623472084218"><td class="cellrowborder" valign="top" headers="mcps1.2.9.1.1 "><p id="p92341220134219"><a name="p92341220134219"></a><a name="p92341220134219"></a>rmdir</p> 446</td> 447<td class="cellrowborder" valign="top" headers="mcps1.2.9.1.2 "><p id="p1234220144217"><a name="p1234220144217"></a><a name="p1234220144217"></a>删除目录</p> 448</td> 449<td class="cellrowborder" valign="top" headers="mcps1.2.9.1.3 "><p id="p1034615175618"><a name="p1034615175618"></a><a name="p1034615175618"></a>√</p> 450</td> 451<td class="cellrowborder" valign="top" headers="mcps1.2.9.1.4 "><p id="p123567595611"><a name="p123567595611"></a><a name="p123567595611"></a>√</p> 452</td> 453<td class="cellrowborder" valign="top" headers="mcps1.2.9.1.5 "><p id="p63654555619"><a name="p63654555619"></a><a name="p63654555619"></a>√</p> 454</td> 455<td class="cellrowborder" valign="top" headers="mcps1.2.9.1.6 "><p id="p1737485135619"><a name="p1737485135619"></a><a name="p1737485135619"></a>√</p> 456</td> 457<td class="cellrowborder" valign="top" headers="mcps1.2.9.1.7 "><p id="p179508533337"><a name="p179508533337"></a><a name="p179508533337"></a>×</p> 458</td> 459</tr> 460<tr id="row1991017101176"><td class="cellrowborder" valign="top" headers="mcps1.2.9.1.1 "><p id="p09101210171712"><a name="p09101210171712"></a><a name="p09101210171712"></a>chdir</p> 461</td> 462<td class="cellrowborder" valign="top" headers="mcps1.2.9.1.2 "><p id="p1091014106172"><a name="p1091014106172"></a><a name="p1091014106172"></a>切换当前路径</p> 463</td> 464<td class="cellrowborder" valign="top" headers="mcps1.2.9.1.3 "><p id="p1338219545610"><a name="p1338219545610"></a><a name="p1338219545610"></a>√</p> 465</td> 466<td class="cellrowborder" valign="top" headers="mcps1.2.9.1.4 "><p id="p173911585618"><a name="p173911585618"></a><a name="p173911585618"></a>√</p> 467</td> 468<td class="cellrowborder" valign="top" headers="mcps1.2.9.1.5 "><p id="p13400053567"><a name="p13400053567"></a><a name="p13400053567"></a>√</p> 469</td> 470<td class="cellrowborder" valign="top" headers="mcps1.2.9.1.6 "><p id="p2040916516565"><a name="p2040916516565"></a><a name="p2040916516565"></a>√</p> 471</td> 472<td class="cellrowborder" valign="top" headers="mcps1.2.9.1.7 "><p id="p497687155612"><a name="p497687155612"></a><a name="p497687155612"></a>√</p> 473</td> 474</tr> 475<tr id="row735414923319"><td class="cellrowborder" valign="top" headers="mcps1.2.9.1.1 "><p id="p19181108339"><a name="p19181108339"></a><a name="p19181108339"></a>getcwd</p> 476</td> 477<td class="cellrowborder" valign="top" headers="mcps1.2.9.1.2 "><p id="p19354129143316"><a name="p19354129143316"></a><a name="p19354129143316"></a>获取当前路径</p> 478</td> 479<td class="cellrowborder" valign="top" headers="mcps1.2.9.1.3 "><p id="p5419165105610"><a name="p5419165105610"></a><a name="p5419165105610"></a>√</p> 480</td> 481<td class="cellrowborder" valign="top" headers="mcps1.2.9.1.4 "><p id="p64281059561"><a name="p64281059561"></a><a name="p64281059561"></a>√</p> 482</td> 483<td class="cellrowborder" valign="top" headers="mcps1.2.9.1.5 "><p id="p174375585616"><a name="p174375585616"></a><a name="p174375585616"></a>√</p> 484</td> 485<td class="cellrowborder" valign="top" headers="mcps1.2.9.1.6 "><p id="p5446452567"><a name="p5446452567"></a><a name="p5446452567"></a>√</p> 486</td> 487<td class="cellrowborder" valign="top" headers="mcps1.2.9.1.7 "><p id="p5986171564"><a name="p5986171564"></a><a name="p5986171564"></a>√</p> 488</td> 489</tr> 490<tr id="row080771185710"><td class="cellrowborder" valign="top" headers="mcps1.2.9.1.1 "><p id="p19826155733610"><a name="p19826155733610"></a><a name="p19826155733610"></a>realpath</p> 491</td> 492<td class="cellrowborder" valign="top" headers="mcps1.2.9.1.2 "><p id="p766310254365"><a name="p766310254365"></a><a name="p766310254365"></a>相对/绝对路径转换</p> 493</td> 494<td class="cellrowborder" valign="top" headers="mcps1.2.9.1.3 "><p id="p04551758568"><a name="p04551758568"></a><a name="p04551758568"></a>√</p> 495</td> 496<td class="cellrowborder" valign="top" headers="mcps1.2.9.1.4 "><p id="p124644516565"><a name="p124644516565"></a><a name="p124644516565"></a>√</p> 497</td> 498<td class="cellrowborder" valign="top" headers="mcps1.2.9.1.5 "><p id="p204731052562"><a name="p204731052562"></a><a name="p204731052562"></a>√</p> 499</td> 500<td class="cellrowborder" valign="top" headers="mcps1.2.9.1.6 "><p id="p34822575610"><a name="p34822575610"></a><a name="p34822575610"></a>√</p> 501</td> 502<td class="cellrowborder" valign="top" headers="mcps1.2.9.1.7 "><p id="p2996107145611"><a name="p2996107145611"></a><a name="p2996107145611"></a>√</p> 503</td> 504</tr> 505<tr id="row194318220214"><td class="cellrowborder" valign="top" headers="mcps1.2.9.1.1 "><p id="p153666165451"><a name="p153666165451"></a><a name="p153666165451"></a>rename</p> 506</td> 507<td class="cellrowborder" valign="top" headers="mcps1.2.9.1.2 "><p id="p1136671615455"><a name="p1136671615455"></a><a name="p1136671615455"></a>文件/目录重命名</p> 508</td> 509<td class="cellrowborder" valign="top" headers="mcps1.2.9.1.3 "><p id="p349119515619"><a name="p349119515619"></a><a name="p349119515619"></a>√</p> 510</td> 511<td class="cellrowborder" valign="top" headers="mcps1.2.9.1.4 "><p id="p95004515561"><a name="p95004515561"></a><a name="p95004515561"></a>√</p> 512</td> 513<td class="cellrowborder" valign="top" headers="mcps1.2.9.1.5 "><p id="p6509253569"><a name="p6509253569"></a><a name="p6509253569"></a>√</p> 514</td> 515<td class="cellrowborder" valign="top" headers="mcps1.2.9.1.6 "><p id="p155199525619"><a name="p155199525619"></a><a name="p155199525619"></a>√</p> 516</td> 517<td class="cellrowborder" valign="top" headers="mcps1.2.9.1.7 "><p id="p3342940193313"><a name="p3342940193313"></a><a name="p3342940193313"></a>×</p> 518</td> 519</tr> 520<tr id="row944217272374"><td class="cellrowborder" valign="top" headers="mcps1.2.9.1.1 "><p id="p1044272714376"><a name="p1044272714376"></a><a name="p1044272714376"></a>chmod</p> 521</td> 522<td class="cellrowborder" valign="top" headers="mcps1.2.9.1.2 "><p id="p1044214273374"><a name="p1044214273374"></a><a name="p1044214273374"></a>修改文件/目录属性</p> 523</td> 524<td class="cellrowborder" valign="top" headers="mcps1.2.9.1.3 "><p id="p43281412135617"><a name="p43281412135617"></a><a name="p43281412135617"></a>√</p> 525</td> 526<td class="cellrowborder" valign="top" headers="mcps1.2.9.1.4 "><p id="p1234641219566"><a name="p1234641219566"></a><a name="p1234641219566"></a>√</p> 527</td> 528<td class="cellrowborder" valign="top" headers="mcps1.2.9.1.5 "><p id="p17442927123717"><a name="p17442927123717"></a><a name="p17442927123717"></a>×</p> 529</td> 530<td class="cellrowborder" valign="top" headers="mcps1.2.9.1.6 "><p id="p1644262714375"><a name="p1644262714375"></a><a name="p1644262714375"></a>×</p> 531</td> 532<td class="cellrowborder" valign="top" headers="mcps1.2.9.1.7 "><p id="p1844218271376"><a name="p1844218271376"></a><a name="p1844218271376"></a>×</p> 533</td> 534</tr> 535<tr id="row74691154211"><td class="cellrowborder" valign="top" headers="mcps1.2.9.1.1 "><p id="p1747111124210"><a name="p1747111124210"></a><a name="p1747111124210"></a>chown</p> 536</td> 537<td class="cellrowborder" valign="top" headers="mcps1.2.9.1.2 "><p id="p0471911114215"><a name="p0471911114215"></a><a name="p0471911114215"></a>修改文件/目录所有者</p> 538</td> 539<td class="cellrowborder" valign="top" headers="mcps1.2.9.1.3 "><p id="p836713125561"><a name="p836713125561"></a><a name="p836713125561"></a>√</p> 540</td> 541<td class="cellrowborder" valign="top" headers="mcps1.2.9.1.4 "><p id="p12377171265616"><a name="p12377171265616"></a><a name="p12377171265616"></a>√</p> 542</td> 543<td class="cellrowborder" valign="top" headers="mcps1.2.9.1.5 "><p id="p122061697438"><a name="p122061697438"></a><a name="p122061697438"></a>×</p> 544</td> 545<td class="cellrowborder" valign="top" headers="mcps1.2.9.1.6 "><p id="p2206159114316"><a name="p2206159114316"></a><a name="p2206159114316"></a>×</p> 546</td> 547<td class="cellrowborder" valign="top" headers="mcps1.2.9.1.7 "><p id="p920609134316"><a name="p920609134316"></a><a name="p920609134316"></a>×</p> 548</td> 549</tr> 550<tr id="row1036123420529"><td class="cellrowborder" valign="top" headers="mcps1.2.9.1.1 "><p id="p730583495314"><a name="p730583495314"></a><a name="p730583495314"></a>stat/lstat</p> 551</td> 552<td class="cellrowborder" valign="top" headers="mcps1.2.9.1.2 "><p id="p1630513410532"><a name="p1630513410532"></a><a name="p1630513410532"></a>查询文件/目录信息</p> 553</td> 554<td class="cellrowborder" valign="top" headers="mcps1.2.9.1.3 "><p id="p338719123568"><a name="p338719123568"></a><a name="p338719123568"></a>√</p> 555</td> 556<td class="cellrowborder" valign="top" headers="mcps1.2.9.1.4 "><p id="p113961712125612"><a name="p113961712125612"></a><a name="p113961712125612"></a>√</p> 557</td> 558<td class="cellrowborder" valign="top" headers="mcps1.2.9.1.5 "><p id="p19388161745612"><a name="p19388161745612"></a><a name="p19388161745612"></a>√</p> 559</td> 560<td class="cellrowborder" valign="top" headers="mcps1.2.9.1.6 "><p id="p163981517185615"><a name="p163981517185615"></a><a name="p163981517185615"></a>√</p> 561</td> 562<td class="cellrowborder" valign="top" headers="mcps1.2.9.1.7 "><p id="p16287141955616"><a name="p16287141955616"></a><a name="p16287141955616"></a>√</p> 563</td> 564</tr> 565<tr id="row16466943145113"><td class="cellrowborder" valign="top" headers="mcps1.2.9.1.1 "><p id="p4871175874615"><a name="p4871175874615"></a><a name="p4871175874615"></a>access</p> 566</td> 567<td class="cellrowborder" valign="top" headers="mcps1.2.9.1.2 "><p id="p187125818465"><a name="p187125818465"></a><a name="p187125818465"></a>查询文件/目录访问权限</p> 568</td> 569<td class="cellrowborder" valign="top" headers="mcps1.2.9.1.3 "><p id="p240531211562"><a name="p240531211562"></a><a name="p240531211562"></a>√</p> 570</td> 571<td class="cellrowborder" valign="top" headers="mcps1.2.9.1.4 "><p id="p141515129564"><a name="p141515129564"></a><a name="p141515129564"></a>√</p> 572</td> 573<td class="cellrowborder" valign="top" headers="mcps1.2.9.1.5 "><p id="p1640821725613"><a name="p1640821725613"></a><a name="p1640821725613"></a>√</p> 574</td> 575<td class="cellrowborder" valign="top" headers="mcps1.2.9.1.6 "><p id="p114181417125618"><a name="p114181417125618"></a><a name="p114181417125618"></a>√</p> 576</td> 577<td class="cellrowborder" valign="top" headers="mcps1.2.9.1.7 "><p id="p1829741985617"><a name="p1829741985617"></a><a name="p1829741985617"></a>√</p> 578</td> 579</tr> 580<tr id="row780042214211"><td class="cellrowborder" rowspan="5" valign="top" width="22.547745225477453%" headers="mcps1.2.9.1.1 "><p id="p206804542364"><a name="p206804542364"></a><a name="p206804542364"></a>分区操作</p> 581</td> 582<td class="cellrowborder" valign="top" width="22.547745225477453%" headers="mcps1.2.9.1.2 "><p id="p1380192264218"><a name="p1380192264218"></a><a name="p1380192264218"></a>mount</p> 583</td> 584<td class="cellrowborder" valign="top" width="22.547745225477453%" headers="mcps1.2.9.1.3 "><p id="p38011522104210"><a name="p38011522104210"></a><a name="p38011522104210"></a>挂载分区</p> 585</td> 586<td class="cellrowborder" valign="top" width="5.499450054994501%" headers="mcps1.2.9.1.4 "><p id="p10424191245618"><a name="p10424191245618"></a><a name="p10424191245618"></a>√</p> 587</td> 588<td class="cellrowborder" valign="top" width="5.949405059494051%" headers="mcps1.2.9.1.5 "><p id="p24341126561"><a name="p24341126561"></a><a name="p24341126561"></a>√</p> 589</td> 590<td class="cellrowborder" valign="top" width="6.419358064193579%" headers="mcps1.2.9.1.6 "><p id="p3428151785614"><a name="p3428151785614"></a><a name="p3428151785614"></a>√</p> 591</td> 592<td class="cellrowborder" valign="top" width="6.95930406959304%" headers="mcps1.2.9.1.7 "><p id="p12437111785613"><a name="p12437111785613"></a><a name="p12437111785613"></a>√</p> 593</td> 594<td class="cellrowborder" valign="top" width="7.529247075292471%" headers="mcps1.2.9.1.8 "><p id="p4307161913563"><a name="p4307161913563"></a><a name="p4307161913563"></a>√</p> 595</td> 596</tr> 597<tr id="row4684182822512"><td class="cellrowborder" valign="top" headers="mcps1.2.9.1.1 "><p id="p1468412813252"><a name="p1468412813252"></a><a name="p1468412813252"></a>umount</p> 598</td> 599<td class="cellrowborder" valign="top" headers="mcps1.2.9.1.2 "><p id="p26846284258"><a name="p26846284258"></a><a name="p26846284258"></a>卸载分区</p> 600</td> 601<td class="cellrowborder" valign="top" headers="mcps1.2.9.1.3 "><p id="p044321275614"><a name="p044321275614"></a><a name="p044321275614"></a>√</p> 602</td> 603<td class="cellrowborder" valign="top" headers="mcps1.2.9.1.4 "><p id="p84531312125615"><a name="p84531312125615"></a><a name="p84531312125615"></a>√</p> 604</td> 605<td class="cellrowborder" valign="top" headers="mcps1.2.9.1.5 "><p id="p244720173564"><a name="p244720173564"></a><a name="p244720173564"></a>√</p> 606</td> 607<td class="cellrowborder" valign="top" headers="mcps1.2.9.1.6 "><p id="p104571517155619"><a name="p104571517155619"></a><a name="p104571517155619"></a>√</p> 608</td> 609<td class="cellrowborder" valign="top" headers="mcps1.2.9.1.7 "><p id="p173412575334"><a name="p173412575334"></a><a name="p173412575334"></a>×</p> 610</td> 611</tr> 612<tr id="row5177163172511"><td class="cellrowborder" valign="top" headers="mcps1.2.9.1.1 "><p id="p617843117252"><a name="p617843117252"></a><a name="p617843117252"></a>statfs</p> 613</td> 614<td class="cellrowborder" valign="top" headers="mcps1.2.9.1.2 "><p id="p181781531192519"><a name="p181781531192519"></a><a name="p181781531192519"></a>查询挂载分区信息</p> 615</td> 616<td class="cellrowborder" valign="top" headers="mcps1.2.9.1.3 "><p id="p144623124566"><a name="p144623124566"></a><a name="p144623124566"></a>√</p> 617</td> 618<td class="cellrowborder" valign="top" headers="mcps1.2.9.1.4 "><p id="p1747251235611"><a name="p1747251235611"></a><a name="p1747251235611"></a>√</p> 619</td> 620<td class="cellrowborder" valign="top" headers="mcps1.2.9.1.5 "><p id="p446813179565"><a name="p446813179565"></a><a name="p446813179565"></a>√</p> 621</td> 622<td class="cellrowborder" valign="top" headers="mcps1.2.9.1.6 "><p id="p147781716561"><a name="p147781716561"></a><a name="p147781716561"></a>√</p> 623</td> 624<td class="cellrowborder" valign="top" headers="mcps1.2.9.1.7 "><p id="p4178133182515"><a name="p4178133182515"></a><a name="p4178133182515"></a>√</p> 625</td> 626</tr> 627<tr id="row1769881513348"><td class="cellrowborder" valign="top" headers="mcps1.2.9.1.1 "><p id="p156992015143419"><a name="p156992015143419"></a><a name="p156992015143419"></a>format</p> 628</td> 629<td class="cellrowborder" valign="top" headers="mcps1.2.9.1.2 "><p id="p16935183513394"><a name="p16935183513394"></a><a name="p16935183513394"></a>格式化分区</p> 630</td> 631<td class="cellrowborder" valign="top" headers="mcps1.2.9.1.3 "><p id="p19289615195611"><a name="p19289615195611"></a><a name="p19289615195611"></a>√</p> 632</td> 633<td class="cellrowborder" valign="top" headers="mcps1.2.9.1.4 "><p id="p14186550113916"><a name="p14186550113916"></a><a name="p14186550113916"></a>×</p> 634</td> 635<td class="cellrowborder" valign="top" headers="mcps1.2.9.1.5 "><p id="p382435053911"><a name="p382435053911"></a><a name="p382435053911"></a>×</p> 636</td> 637<td class="cellrowborder" valign="top" headers="mcps1.2.9.1.6 "><p id="p1246615123918"><a name="p1246615123918"></a><a name="p1246615123918"></a>×</p> 638</td> 639<td class="cellrowborder" valign="top" headers="mcps1.2.9.1.7 "><p id="p13818525391"><a name="p13818525391"></a><a name="p13818525391"></a>×</p> 640</td> 641</tr> 642<tr id="row4270132114219"><td class="cellrowborder" valign="top" headers="mcps1.2.9.1.1 "><p id="p958455012219"><a name="p958455012219"></a><a name="p958455012219"></a>sync</p> 643</td> 644<td class="cellrowborder" valign="top" headers="mcps1.2.9.1.2 "><p id="p125840501224"><a name="p125840501224"></a><a name="p125840501224"></a>分区内容刷入设备</p> 645</td> 646<td class="cellrowborder" valign="top" headers="mcps1.2.9.1.3 "><p id="p8300115125612"><a name="p8300115125612"></a><a name="p8300115125612"></a>√</p> 647</td> 648<td class="cellrowborder" valign="top" headers="mcps1.2.9.1.4 "><p id="p25044812404"><a name="p25044812404"></a><a name="p25044812404"></a>×</p> 649</td> 650<td class="cellrowborder" valign="top" headers="mcps1.2.9.1.5 "><p id="p17501248184019"><a name="p17501248184019"></a><a name="p17501248184019"></a>×</p> 651</td> 652<td class="cellrowborder" valign="top" headers="mcps1.2.9.1.6 "><p id="p1850154824012"><a name="p1850154824012"></a><a name="p1850154824012"></a>×</p> 653</td> 654<td class="cellrowborder" valign="top" headers="mcps1.2.9.1.7 "><p id="p18505483404"><a name="p18505483404"></a><a name="p18505483404"></a>×</p> 655</td> 656</tr> 657</tbody> 658</table> 659 660### 开发流程<a name="section64113023616"></a> 661 662文件系统的主要开发流程包括挂载/卸载分区，以及系列目录/文件操作。 663 664### 编程实例<a name="section236041883618"></a> 665 666代码实现如下： 667 668``` 669#include <stdio.h> 670#include <string.h> 671#include "sys/stat.h" 672#include "fcntl.h" 673#include "unistd.h" 674 675#define LOS_OK 0 676#define LOS_NOK -1 677 678int main(void) 679{ 680 int ret; 681 int fd = -1; 682 ssize_t len; 683 off_t off; 684 char mntName[20] = "/storage"; 685 char devName[20] = "/dev/mmcblk0p0"; 686 char dirName[20] = "/storage/test"; 687 char fileName[20] = "/storage/test/file.txt"; 688 char writeBuf[20] = "Hello OpenHarmony!"; 689 char readBuf[20] = {0}; 690 691 /* 创建目录“/storage” */ 692 ret = mkdir(mntName, 0777); 693 if (ret != LOS_OK) { 694 printf("mkdir failed.\n"); 695 return LOS_NOK; 696 } 697 698 /* 挂载设备“/dev/mmcblk0p0”到“/storage” */ 699 ret = mount(devName, mntName, "vfat", 0, 0); 700 if (ret != LOS_OK) { 701 printf("mount failed.\n"); 702 return LOS_NOK; 703 } 704 705 /* 创建目录“/storage/test” */ 706 ret = mkdir(dirName, 0777); 707 if (ret != LOS_OK) { 708 printf("mkdir failed.\n"); 709 return LOS_NOK; 710 } 711 712 /* 创建可读写文件“/storage/test/file.txt” */ 713 fd = open(fileName, O_RDWR | O_CREAT, 0777); 714 if (fd < 0) { 715 printf("open file failed.\n"); 716 return LOS_NOK; 717 } 718 719 /* 将writeBuf中的内容写入文件 */ 720 len = write(fd, writeBuf, strlen(writeBuf)); 721 if (len != strlen(writeBuf)) { 722 printf("write file failed.\n"); 723 return LOS_NOK; 724 } 725 726 /* 将文件内容刷入存储设备中 */ 727 ret = fsync(fd); 728 if (ret != LOS_OK) { 729 printf("fsync failed.\n"); 730 return LOS_NOK; 731 } 732 733 /* 将读写指针偏移至文件头 */ 734 off = lseek(fd, 0, SEEK_SET); 735 if (off != 0) { 736 printf("lseek failed.\n"); 737 return LOS_NOK; 738 } 739 740 /* 将文件内容读出至readBuf中，读取长度为readBuf大小 */ 741 len = read(fd, readBuf, sizeof(readBuf)); 742 if (len != strlen(readBuf)) { 743 printf("read file failed.\n"); 744 return LOS_NOK; 745 } 746 printf("%s\n", readBuf); 747 748 /* 关闭文件 */ 749 ret = close(fd); 750 if (ret != LOS_OK) { 751 printf("close failed.\n"); 752 return LOS_NOK; 753 } 754 755 /* 删除文件“/storage/test/file.txt” */ 756 ret = unlink(fileName); 757 if (ret != LOS_OK) { 758 printf("unlink failed.\n"); 759 return LOS_NOK; 760 } 761 762 /* 删除目录“/storage/test” */ 763 ret = rmdir(dirName); 764 if (ret != LOS_OK) { 765 printf("rmdir failed.\n"); 766 return LOS_NOK; 767 } 768 769 /* 卸载分区“/storage” */ 770 ret = umount(mntName); 771 if (ret != LOS_OK) { 772 printf("umount failed.\n"); 773 return LOS_NOK; 774 } 775 776 /* 删除目录“/storage” */ 777 ret = rmdir(mntName); 778 if (ret != LOS_OK) { 779 printf("rmdir failed.\n"); 780 return LOS_NOK; 781 } 782 783 return LOS_OK; 784} 785``` 786 787**结果验证** 788 789编译运行得到的结果为： 790 791``` 792Hello OpenHarmony! 793``` 794 795