网站限定域名,四川建设机械网站,湛江专业舞台制作,网站开发框架具体是什么android的启动脚本(init.rc)文件的语法#xff0c;参考资料#xff1a;Android 初始化语言(Android Init Language)Android初始化脚本语言包含四种类型的语句#xff1a;动作(Actions)指令(Commands)服务(Services)选项(Options)该语言的语法包括下列约定#xff1a;所有类…android的启动脚本(init.rc)文件的语法参考资料Android 初始化语言(Android Init Language)Android初始化脚本语言包含四种类型的语句动作(Actions)指令(Commands)服务(Services)选项(Options)该语言的语法包括下列约定所有类型的语句都是基于行(line-oriented)的一个语句包含若干个tokenstoken之间通过空格字符分隔.如果一个token中需要包含空格字符则需要通过C语言风格的反斜线(\)来转义或者使用双引号把整个token引起来。反斜线还可以出现在一行的末尾表示下一行的内容仍然属于当前语句。以#开始的行是注释行。动作(Actions)和服务(Services)语句隐含表示一个新的段落(section)的开始。所有的指令(commands)和选项(options)归属于上方最近的一个段落。在第一个段落之前的指令(commands)和选项(options)是无效的。动作(Actions)和服务(Services)拥有唯一性的名字。如果出现重名那么后出现的定义将被作为错误忽略掉。动作(Actions)动作(Actions)是一个有名字的指令(commands)序列。每个动作(Actions)都定义一个触发条件(trigger)用于指示什么时候执行这个动作。当与动作的触发器匹配的事件发生时该动作将被添加到一个即将被执行的队列的队尾(除非它已经在队列中)。队列中的每一个动作被依次取出执行动作中的每一个指令也将依次执行。初始化程序(Init)在执行一个动作的各项指令的期间还需要处理其它操作(比如设备创建/销毁属性设置进程重启)。一个动作定义的形式如下on服务(Services)服务是初始化程序需要启动的一些程序初始化程序还有可能会在这些程序退出之后重启它们。Services take 一个服务定义的形式如下service [ ]*...选项(Options)选项将影响控制初始化程序运行服务的时机和方法。可能的选项如下表。选项说明disabledThis service will not automaticallystart with its class. It must be explicitly started by name.socket[ [ ]]Create a unix domain socket named /dev/socket/and pass its fd to the launched process. Validvalues include dgram and stream. userand group default to 0.userChange to username before execingthis service. Currently defaults to root.group []*Change to groupname before execingthis service. Additional groupnames beyond the first, which isrequired, are used to set additional groups of the process (with setgroups()).Currently defaults to root.capability [ ]Set linux capability before execingthis serviceoneshotDo not restart the service when itexits.classSpecify a class name for the service.All services in a named class must start and stop together. A serviceis considered of class default if one is not specified via the classoption.触发器(Triggers)触发器是一个字符串用于匹配特定的事件这些事件将触发触发器所属动作(Actions)的执行。触发器说明bootThis is the first trigger that occurswhen init starts (after /init.conf is loaded).Triggers of this form occur when theproperty is set to the specific value .device-added-device-removed-Triggers of these forms occur when adevice node is added or removed.service-exited-Triggers of this form occur when thespecified service exits.指令(Commands)CommandDescriptionexec []*Fork and execute a program ().This will block until the program completes execution. Try to avoidexec. Unlike the builtin commands, it runs the risk ofgetting init stuck.exportSet the environment variableequal to in the global environment (whichwill be inherited by all processes started after this command isexecuted).ifupBring the network interfaceonline.importParse an init config file, extendingthe current configuration.hostnameSet the host name.class_startStart all services of the specifiedclass if they are not already running.class_stopStop all services of the specifiedclass if they are currently running.domainnameSet the domain name.insmodInstall the module at .mkdirMake a directory at .mount [ ]*Attempt to mount the named device atthe directory . Thismay be of the form mtdname to specify a mtd block device by name.setkey- currenlty undefined -setpropSet system propertyto .setrlimitSet the rlimit for a resource.startStart a service running if it is notalready running.stopStop a service from running if it iscurrently running.symlinkCreate a symbolic link atwith the value .write [ ]*Open the file atand write one or more strings to it with write(2).属性(Properties)初始化程序(Init)可以根据需要修改一些系统的属性。属性说明init.actionEqual to the name of the actioncurrently being executed or if none.init.commandEqual to the command being executed or if none.init.svc.State of a named service (stopped,running, or restarting).init.rc文件示例on bootexport PATH /sbin:/system/sbin:/system/binexport LD_LIBRARY_PATH /system/libmkdir /devmkdir /procmkdir /sysmount tmpfs tmpfs /devmkdir /dev/ptsmkdir /dev/socketmount devpts devpts /dev/ptsmount proc proc /procmount sysfs sysfs /syswrite /proc/cpu/alignment 4ifup lohostname localhostdomainname localhostmount yaffs2 mtdsystem /systemmount yaffs2 mtduserdata /dataimport /system/etc/init.confclass_start defaultservice adbd /sbin/adbduser adbgroup adbservice usbd /system/bin/usbd -ruser usbdgroup usbdsocket usbd 666service zygote /system/bin/app_process -Xzygote /system/bin --zygotesocket zygote 666service runtime /system/bin/runtimeuser systemgroup systemon device-added-/dev/compassstart akmdon device-removed-/dev/compassstop akmdservice akmd /sbin/akmddisableduser akmdgroup akmd
