一文看懂嵌入式/etc/init.d/目录下的所有启动文件

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一文看懂嵌入式/etc/init.d/目录下的所有启动文件

2023-11-23 00:37| 来源: 网络整理| 查看: 265

本目录下的所有文件

[root@EPC-M6G2C init.d]# ls S01logging* S30dbus* S50telnet* S90start_userapp.sh* S10udev* S40network* S70vsftpd* socketcand* S13portmap* S50dropbear* S80mount-opt* rcK* S20urandom* S50sshd* S81web.sh* rcS*

先看一下rcS文件，它是本目录在开机时最先启动的文件

file:rcS #!/bin/sh # Start all init scripts in /etc/init.d # executing them in numerical order. # for i in /etc/init.d/S??* ;do # Ignore dangling symlinks (if any). [ ! -f "$i" ] && continue #如果是目录或设备文件则遍历下一个 case "$i" in *.sh) #.sh结尾的脚本 # Source shell script for speed. ( trap - INT QUIT TSTP #重置陷阱为启动shell时的陷阱 set start #设置传入的参数 . $i #执行，携带start参数 ) ;; *) #其他脚本 # No sh extension, so fork subprocess. $i start #执行，携带start参数 ;; esac done

总结：检测大写S开头的所有脚本并执行它们。 trap 命令

rcK文件是设备关机或重启执行的文件，它和rcS差不多，只有传入的参数有微微差别

file:rcK #!/bin/sh # Stop all init scripts in /etc/init.d # executing them in reversed numerical order. # for i in $(ls -r /etc/init.d/S??*) ;do #$()相当于反引号，首先执行命令，-r倒序排列 # Ignore dangling symlinks (if any). [ ! -f "$i" ] && continue #如果不存在则遍历下一个 case "$i" in *.sh) # Source shell script for speed. ( trap - INT QUIT TSTP set stop . $i #执行，携带stop参数 ) ;; *) # No sh extension, so fork subprocess. $i stop #执行，携带stop参数 ;; esac done

总结：关机时还需要启动一遍启动脚本，只不过传入的参数是stop，需要处理一些后续工作才关机。

file:S01logging #!/bin/sh # # Start logging # start() { echo -n "Starting logging: " start-stop-daemon -b -S -q -m -p /var/run/syslogd.pid --exec /sbin/syslogd -- -n start-stop-daemon -b -S -q -m -p /var/run/klogd.pid --exec /sbin/klogd -- -n echo "OK" } stop() { echo -n "Stopping logging: " start-stop-daemon -K -q -p /var/run/syslogd.pid start-stop-daemon -K -q -p /var/run/klogd.pid echo "OK" } case "$1" in start) start ;; stop) stop ;; restart|reload) stop start ;; *) echo "Usage: $0 {start|stop|restart}" exit 1 esac exit $? #最后一次命令的执行状态码，0为正常。

file:S10udev #!/bin/sh # # udev This is a minimal non-LSB version of a UDEV startup script. It # was derived by stripping down the udev-058 LSB version for use # with buildroot on embedded hardware using Linux 2.6.34+ kernels. # # You may need to customize this for your system's resource limits # (including startup time!) and administration. For example, if # your early userspace has a custom initramfs or initrd you might # need /dev much earlier; or without hotpluggable busses (like USB, # PCMCIA, MMC/SD, and so on) your /dev might be static after boot. # # This script assumes your system boots right into the eventual root # filesystem, and that init runs this udev script before any programs # needing more device nodes than the bare-bones set -- /dev/console, # /dev/zero, /dev/null -- that's needed to boot and run this script. # # Check for missing binaries UDEV_BIN=/sbin/udevd test -x $UDEV_BIN || exit 5 #文件不可执行则退出，退出码：5 # Check for config file and read it UDEV_CONFIG=/etc/udev/udev.conf test -r $UDEV_CONFIG || exit 6 #文件不可读则退出，退出码：6 . $UDEV_CONFIG case "$1" in start) #设备开机时 printf "Populating ${udev_root:-/dev} using udev: " printf '\000\000\000\000' > /proc/sys/kernel/hotplug $UDEV_BIN -d || (echo "FAIL" && exit 1) #执行失败打印“FAIL”并退出 udevadm trigger --type=subsystems --action=add udevadm trigger --type=devices --action=add udevadm settle --timeout=30 || echo "udevadm settle failed" echo "done" ;; stop) #设备关机或重启 # Stop execution of events udevadm control --stop-exec-queue killall udevd ;; *) echo "Usage: $0 {start|stop}" exit 1 ;; esac exit 0

udevadm命令详解 udevadm trigger [options]　　接收内核发送来的设备事件。主要用于重放coldplug事件信息 –type=type 　　　　　　　触发一个特殊的设备。合法的类型：devices,subsystem,failed.默认是devices –action=action　　　　　　被触发的事件，默认是change

udevadm settle [options]　　查看udev事件队列，如果所有事件全部处理完就退出。 –timeout=seconds　　　　等待事件队列空的最大时间。默认是180秒。如果是0则立即退出。

udevadm control [options] 　控制udev守护进程(systemd-udevd)的内部状态。 -s, --stop-exec-queue 　　向 systemd-udevd 发送"禁止处理事件"信号，这样所有新发生的事件都将进入等候队列。

file:S13portmap #! /bin/sh [ -f /sbin/portmap ] || exit 0 #不存在此文件就退出 start() { echo -n "Starting portmap: " portmap mkdir -p /var/lock/subsys touch /var/lock/subsys/portmap #锁定此服务 echo "done" } stop() { echo -n "Stopping portmap: " echo killall portmap rm -rf /var/lock/subsys echo "done" } restart() { stop start rm -f /var/run/portmap.state } # See how we were called. case "$1" in start) start ;; stop) stop ;; restart|reload) restart ;; *) echo "Usage: $0 {start|stop|reload|restart}" exit 1 esac exit $?

参考：portmap的作用

file:S20urandom #! /bin/sh # # urandom This script saves the random seed between reboots. # It is called from the boot, halt and reboot scripts. # # Version: @(#)urandom 1.33 22-Jun-1998 [email protected] # [ -c /dev/urandom ] || exit 0 #不存在字符设备urandom就退出 #. /etc/default/rcS case "$1" in start|"") # check for read only file system if ! touch /etc/random-seed 2>/dev/null #如果无法创建random-seed文件 then echo "read-only file system detected...done" #检测到只读文件系统 exit #退出 fi if [ "$VERBOSE" != no ] then echo -n "Initializing random number generator... " fi # Load and then save 512 bytes, # which is the size of the entropy pool cat /etc/random-seed >/dev/urandom rm -f /etc/random-seed umask 077 #配置文件夹默认权限 dd if=/dev/urandom of=/etc/random-seed count=1 \ >/dev/null 2>&1 || echo "urandom start: failed." umask 022 [ "$VERBOSE" != no ] && echo "done." ;; stop) if ! touch /etc/random-seed 2>/dev/null then exit fi # Carry a random seed from shut-down to start-up; # see documentation in linux/drivers/char/random.c [ "$VERBOSE" != no ] && echo -n "Saving random seed... " umask 077 dd if=/dev/urandom of=/etc/random-seed count=1 \ >/dev/null 2>&1 || echo "urandom stop: failed." [ "$VERBOSE" != no ] && echo "done." ;; *) echo "Usage: urandom {start|stop}" >&2 exit 1 ;; esac

dd命令详解

file:S30dbus #!/bin/sh # # messagebus: The D-BUS systemwide message bus # # chkconfig: 345 97 03 # description: This is a daemon which broadcasts notifications of system events \ # and other messages. See http://www.freedesktop.org/software/dbus/ # # processname: dbus-daemon # pidfile: /var/run/messagebus.pid # # Sanity checks. [ -x /usr/bin/dbus-daemon ] || exit 0 #非可执行文件则退出 # Create needed directories. [ -d /var/run/dbus ] || mkdir -p /var/run/dbus #无此目录则创建, -p 循环创建，多层目录结构 [ -d /var/lock/subsys ] || mkdir -p /var/lock/subsys [ -d /tmp/dbus ] || mkdir -p /tmp/dbus RETVAL=0 start() { echo -n "Starting system message bus: " dbus-uuidgen --ensure dbus-daemon --system RETVAL=$? echo "done" [ $RETVAL -eq 0 ] && touch /var/lock/subsys/dbus-daemon #dbus-daemon命令执行正常,锁定 } stop() { echo -n "Stopping system message bus: " ## we don't want to kill all the per-user $processname, we want ## to use the pid file *only*; because we use the fake nonexistent ## program name "$servicename" that should be safe-ish killall dbus-daemon RETVAL=$? echo "done" if [ $RETVAL -eq 0 ]; then rm -f /var/lock/subsys/dbus-daemon rm -f /var/run/messagebus.pid fi } # See how we were called. case "$1" in start) start ;; stop) stop ;; status) status $processname RETVAL=$? ;; restart) stop start ;; condrestart) if [ -f /var/lock/subsys/$servicename ]; then stop start fi ;; reload) echo "Message bus can't reload its configuration, you have to restart it" RETVAL=$? ;; *) echo "Usage: $0 {start|stop|status|restart|condrestart|reload}" ;; esac exit $RETVAL

dbus-uuidgen 命令生成或读取一个全局唯一ID –ensure[=FILENAME] 如果未提供文件名，则默认为 localstatedir / lib / dbus / machine-id（localstatedir通常为/ var）。如果该文件存在，则将对其进行验证，如果包含错误的内容，则返回失败代码。如果该文件不存在，则将使用新的uuid创建该文件。成功时，不输出任何输出。

dbus-daemon — Message bus daemon 消息总线守护进程 –system 使用系统范围消息总线的标准配置文件。

file:S40network #!/bin/sh # # Start the network.... # # Debian ifupdown needs the /run/network lock directory mkdir -p /run/network case "$1" in start) echo "Starting network..." /sbin/ifup -a ;; stop) echo -n "Stopping network..." /sbin/ifdown -a ;; restart|reload) "$0" stop "$0" start ;; *) echo "Usage: $0 {start|stop|restart}" exit 1 esac exit $?

ifup eth0 #激活eth0 ifdown eth0 #禁用eth0 -a 自动配置(禁用)所有接口

file:S50dropbear #!/bin/sh # # Starts dropbear sshd. # # Allow a few customizations from a config file test -r /etc/default/dropbear && . /etc/default/dropbear #为可读文件则执行 start() { DROPBEAR_ARGS="$DROPBEAR_ARGS -R" # If /etc/dropbear is a symlink to /var/run/dropbear, and # - the filesystem is RO (i.e. we can not rm the symlink), # create the directory pointed to by the symlink. # - the filesystem is RW (i.e. we can rm the symlink), # replace the symlink with an actual directory if [ -L /etc/dropbear \ #是一个符号链接 -a "$(readlink /etc/dropbear)" = "/var/run/dropbear" ] #文件存在 then if rm -f /etc/dropbear >/dev/null 2>&1; then #错误输出重定向到标准输出,标准输出重定向到空文件(不打印任何东西) mkdir -p /etc/dropbear #成功删除则创建此目录 else echo "No persistent location to store SSH host keys. New keys will be" echo "generated at each boot. Are you sure this is what you want to do?" mkdir -p "$(readlink /etc/dropbear)" fi fi echo -n "Starting dropbear sshd: " umask 077 start-stop-daemon -S -q -p /var/run/dropbear.pid \ --exec /usr/sbin/dropbear -- $DROPBEAR_ARGS [ $? = 0 ] && echo "OK" || echo "FAIL" } stop() { echo -n "Stopping dropbear sshd: " start-stop-daemon -K -q -p /var/run/dropbear.pid [ $? = 0 ] && echo "OK" || echo "FAIL" } restart() { stop start } case "$1" in start) start ;; stop) stop ;; restart|reload) restart ;; *) echo "Usage: $0 {start|stop|restart}" exit 1 esac exit $?

file:S50sshd #!/bin/sh # # sshd Starts sshd. # # Make sure the ssh-keygen progam exists [ -f /usr/bin/ssh-keygen ] || exit 0 # Create any missing keys /usr/bin/ssh-keygen -A umask 077 start() { echo -n "Starting sshd: " /usr/sbin/sshd wr touch /var/lock/sshd echo "OK" } stop() { echo -n "Stopping sshd: " wr killall sshd wr rm -f /var/lock/sshd echo "OK" } restart() { stop start } case "$1" in start) start ;; stop) stop ;; restart|reload) restart ;; *) echo "Usage: $0 {start|stop|restart}" exit 1 esac exit $?

ssh-keygen -A 对于主机密钥不存在的每个密钥类型(rsa1、rsa、dsa、ecdsa和ed25519)，生成带有默认密钥文件路径、空口令、密钥类型的默认位和默认注释的主机密钥。系统管理脚本使用它来生成新的主机密钥。因此，如果您的系统还没有主机密钥，ssh-keygen -A将创建它们。参考：ssh-keygen 中文手册

file:S50telnet #!/bin/sh # # Start telnet.... # start() { echo -n "Starting telnetd: " start-stop-daemon -S -q -m -b -p /var/run/telnetd.pid \ -x /usr/sbin/telnetd -- -F [ $? = 0 ] && echo "OK" || echo "FAIL" } stop() { echo -n "Stopping telnetd: " start-stop-daemon -K -q -p /var/run/telnetd.pid \ -x /usr/sbin/telnetd [ $? = 0 ] && echo "OK" || echo "FAIL" } case "$1" in start) start ;; stop) stop ;; restart|reload) stop start ;; *) echo "Usage: $0 {start|stop|restart}" exit 1 esac exit $?

file:S70vsftpd #! /bin/sh set -e DESC="vsftpd" NAME=vsftpd DAEMON=/usr/sbin/$NAME case "$1" in start) echo -n "Starting $DESC: " start-stop-daemon -S -b -x $NAME echo "OK" ;; stop) echo -n "Stopping $DESC: " start-stop-daemon -K -x $NAME echo "OK" ;; restart|force-reload) echo "Restarting $DESC: " $0 stop sleep 1 $0 start echo "" ;; *) echo "Usage: $0 {start|stop|restart|force-reload}" >&2 exit 1 ;; esac exit 0

start-stop-daemon守护进程启停工具命令参数 -S | --start – 开启一个系统守护程序，并传递参数给它 -K | --stop 停止一个程序 -b | --background 后台运行 -x | --exec 程序启动/检查它是否正在运行

file:S80mount-opt #!/bin/sh # # mount /dev/mtdblock6 of nandflash in /opt directory # start() { echo -n "Start mount /opt: " ubiattach /dev/ubi_ctrl -m 6 -d 1 && mount -t ubifs ubi1_0 /opt #ubifs文件系统ubi1_0挂载到/opt目录下 if [ $? == 0 ]; then #上一条命令：挂载成功返回0 echo "Mount /opt ok" else echo "flash_erase /dev/mtd6" ubidetach -p /dev/mtd6 flash_erase /dev/mtd6 0 0 ubiformat /dev/mtd6 ubiattach /dev/ubi_ctrl -m 6 -d 1 ubimkvol /dev/ubi1 -N opt -m mount -t ubifs ubi1_0 /opt fi } stop() { echo -n "Unmount /opt: " umount /opt ubidetach -p /dev/mtd6 echo "Unmount /opt OK" } restart() { stop start } case "$1" in start) start ;; stop) stop ;; restart|reload) restart ;; *) echo "Usage: $0 {start|stop|restart}" exit 1 esac exit $?

ubi命令用法 ubiattach -m, --mtdn=此选项是必须的 MTD device number to attach (alternative method, e.g if the character device node does not exist) 。附加的MTD设备编号(替代方法,e.g 如果字符设备节点不存在) 注意：是从0开始的。 -d, --devn= the number to assign to the newly created UBI device (assigned automatically if this is not specified) 分配给新创建的UBI设备的号码(如果没有指定，则自动分配)

ubidetach -p, --dev-path= 要附加的MTD设备节点的路径。

ubiformat 格式化MTD设备，擦除Flash，保存擦除计数，写入UBI镜像到Flash。 flash_erase命令有类似的效果。

ubimkvol 从UBI设备上创建UBI卷。 -N, --name= 卷名。 -m, --maxavsize 将卷大小设置为最大可用大小。

file:S81web.sh #!/bin/sh /usr/local/webs/bin/webs & file:S90start_userapp.sh #!/bin/sh # set ip ifconfig eth0 192.168.1.131 #配置eth0接口网络 ifconfig eth1 192.168.2.136 # disable rtc clk_out pins default echo 0 > /sys/class/rtc/rtc0/device/clk_out_ctl #禁用RTC clk_out引脚 # if test function in sd card then exec if [ -f "/media/mmcblk0p1/function/functiontest.sh" ]; then #内存卡自定义程序 echo "Start functiontest.sh" cd /media/mmcblk0p1/function ./functiontest.sh & fi # you can add your app start_command here file:socketcand #! /bin/sh ### BEGIN INIT INFO # Provides: socketcand # Required-Start: $remote_fs # Required-Stop: $remote_fs # Default-Start: 2 3 4 5 # Default-Stop: # Short-Description: socketcand # Description: daemon that provides network access to local CAN busses ### END INIT INFO [ -f /etc/default/rcS ] && . /etc/default/rcS #一般文件(非目录或设备文件) PATH=/bin:/usr/bin:/sbin:/usr/sbin prefix=/usr exec_prefix=/usr DAEMON=${exec_prefix}/bin/socketcand DESC="SocketCAN daemon" NAME="socketcand" PIDFILE=/var/run/socketcand.pid test -x $DAEMON || exit 0 #/usr/bin/socketcand文件非可执行文件则退出 case "$1" in start) echo "Starting $DESC" "$NAME" start-stop-daemon --start --quiet --background --pidfile $PIDFILE --startas $DAEMON -m -- --daemon ;; stop) echo "Stopping $DESC" "$NAME" start-stop-daemon --stop --quiet --pidfile $PIDFILE --oknodo --startas $DAEMON rm -f $PIDFILE ;; restart) $0 stop sleep 1 $0 start ;; force-reload) if start-stop-daemon --stop --test --quiet --pidfile $PIDFILE --startas $DAEMON ; then $0 restart fi ;; *) echo "Usage: /etc/init.d/socketcand {start|stop|restart|force-reload}" exit 1 ;; esac exit 0

示例： Start the food daemon, unless one is already running (a process named food, running as user food, with pid in food.pid) 启动food守护进程，除非它已经在运行(一个名为food的进程，以用户food的身份运行，在foo.pid中使用pid):

start-stop-daemon --start --oknodo --user food --name food --pidfile /var/run/food.pid --startas /usr/sbin/food --chuid food -- --daemon

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一文看懂嵌入式/etc/init.d/目录下的所有启动文件

一文看懂嵌入式/etc/init.d/目录下的所有启动文件

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