#!/bin/sh
#
# rc This file is responsible for starting/stopping
# services when the runlevel changes.
#
# Optimization feature:
# A startup script is _not_ run when the service was
# running in the previous runlevel and it wasn't stopped
# in the runlevel transition (most Debian services don't
# have K?? links in rc{,,,,} )
#
# Author: Miquel van Smoorenburg <miquels@cistron.nl>
# Bruce Perens <Bruce@Pixar.com>
#
# Version: @(#)rc 2.78 -Nov- miquels@cistron.nl
# # 一. 参考文档:
# . inittab脚本启动解析
# http://blog.chinaunix.net/uid-17188120-id-4073497.html
# . Customizing the SDK Splash Screen
# http://processors.wiki.ti.com/index.php/Customizing_the_SDK_Splash_Screen
# . psplash进度条旋转成功
# http://www.xuebuyuan.com/1511619.html
#
# -- 深圳 南山平山村 曾剑锋 ##
##
## /etc/default/rcS
##
## Default settings for the scripts in /etc/rcS.d/
##
## For information about these variables see the rcS() manual page.
##
## This file belongs to the "initscripts" package.
#
## delete files in /tmp during boot older than x days.
## '' means always, - or 'infinite' disables the feature
#TMPTIME=
#
## spawn sulogin during boot, continue normal boot if not used in seconds
#SULOGIN=no
#
## do not allow users to log in until the boot has completed
#DELAYLOGIN=no
#
## assume that the BIOS clock is set to UTC time (recommended)
#UTC=yes
#
## be more verbose during the boot process
#VERBOSE=no
#
## automatically repair filesystems with inconsistencies during boot
#FSCKFIX=no
. /etc/default/rcS
export VERBOSE # 在rcS中设置的一些环境变量
# PATH=/sbin:/bin:/usr/sbin:/usr/bin
# runlevel=S
# prevlevel=N
# umask
# export PATH runlevel prevlevel
#
# exec /etc/init.d/rc S # 这个函数名可以认为是重置进度条进度
startup_progress() {
# 当前进度大小=上一次的进度+上每次的进度的变化值
step=$(($step + $step_change))
if [ "$num_steps" != "" ]; then
# 这里相当于重新计算当前step占进度条的百分比
progress=$((($step * $progress_size / $num_steps) + $first_step))
else
# 直接就是100%了
progress=$progress_size
fi
#echo "PROGRESS is $progress $runlevel $first_step + ($step of $num_steps) $step_change $progress_size"
#if type psplash-write >/dev/null 2>&1; then
# TMPDIR=/mnt/.psplash psplash-write "PROGRESS $progress" || true
#fi
# 将上面的progress的值写入fifo中去,echo的值是固定的。
if [ -e /mnt/.psplash/psplash_fifo ]; then
echo "PROGRESS $progress" > /mnt/.psplash/psplash_fifo
fi
} #
# Start script or program.
#
# 启动脚本函数
startup() {
# Handle verbosity
# VERBOSE=no, 不显示这一部分内容
[ "$VERBOSE" = very ] && echo "INIT: Running $@..." case "$1" in
*.sh)
# Source shell script for speed.
# 这里相当于直接执行脚本,丢弃了参数
(
trap - INT QUIT TSTP
scriptname=$
shift
. $scriptname
)
;;
*)
# 执行参数里命令
"$@"
;;
esac
startup_progress
} # Ignore CTRL-C only in this shell, so we can interrupt subprocesses.
# 这里就是捕捉INT QUIT TSTP三个信号,执行“:”,实际就是忽略这三个信号,防止脚本执行时使用ctrl-C 就退出脚本
trap ":" INT QUIT TSTP # Set onlcr to avoid staircase effect.
# 设置onlcr避免楼梯的效果。
stty onlcr >& # Now find out what the current and what the previous runlevel are. runlevel=$RUNLEVEL
#echo "danny add"
echo $
sleep
# Get first argument. Set new runlevel to this argument.
# 由于传进来的参数的$=S,所以这里可以断定的是runlevel是S
[ "$1" != "" ] && runlevel=$
if [ "$runlevel" = "" ]
then
echo "Usage: $0 <runlevel>" >&
exit
fi
# 目前没有看到由有关PREVLEVEL相关的内容,这里previous是N
previous=$PREVLEVEL
[ "$previous" = "" ] && previous=N export runlevel previous # Is there an rc directory for this new runlevel?
if [ -d /etc/rc$runlevel.d ]
then
# Find out where in the progress bar the initramfs got to.
PROGRESS_STATE=
#if [ -f /dev/.initramfs/progress_state ]; then
# . /dev/.initramfs/progress_state
#fi # Split the remaining portion of the progress bar into thirds
# 感觉这里可以认为是:已经出了一部分的脚本了,这部分内容也应该算进去
# 所以给出一部分进度条的空间出来,这样,进度条就不像是从0开始,至少
# 当我们看到图像的时候,psplash这个进程已经跑起来了。
progress_size=$((( - $PROGRESS_STATE) / )) # 这里的runlevel是S
case "$runlevel" in
|)
# Count down from - to and use the entire bar
first_step=-
progress_size=
step_change=
;;
S)
# Begin where the initramfs left off and use /
# of the remaining space
first_step=$PROGRESS_STATE
progress_size=$(($progress_size * )) # 剩下2/
step_change=
;;
*)
# Begin where rcS left off and use the final / of
# the space (by leaving progress_size unchanged)
first_step=$(($progress_size * + $PROGRESS_STATE))
step_change=
;;
esac num_steps=
for s in /etc/rc$runlevel.d/[SK]*; do
case "${s##/etc/rc$runlevel.d/S??}" in
gdm|xdm|kdm|reboot|halt)
break
;;
esac
num_steps=$(($num_steps + ))
done
step= # First, run the KILL scripts.
# 先结束掉需要结束的进程
if [ $previous != N ]
then
for i in /etc/rc$runlevel.d/K[-][-]*
do
# Check if the script is there.
[ ! -f $i ] && continue # Stop the service.
startup $i stop
done
fi # Now run the START scripts for this runlevel.
for i in /etc/rc$runlevel.d/S*
do
[ ! -f $i ] && continue # 这里的previous=N,可以不用关心
if [ $previous != N ] && [ $previous != S ]
then
#
# Find start script in previous runlevel and
# stop script in this runlevel.
#
suffix=${i#/etc/rc$runlevel.d/S[-][-]}
stop=/etc/rc$runlevel.d/K[-][-]$suffix
previous_start=/etc/rc$previous.d/S[-][-]$suffix
#
# If there is a start script in the previous level
# and _no_ stop script in this level, we don't
# have to re-start the service.
#
[ -f $previous_start ] && [ ! -f $stop ] && continue
fi
case "$runlevel" in
|)
startup $i stop
;;
*)
startup $i start
;;
esac
done
fi #Uncomment to cause psplash to exit manually, otherwise it exits when it sees a VC switch
if [ "x$runlevel" != "xS" ] && [ ! -x /etc/init.d/xserver-nodm ]; then
. /etc/init.d/qt.sh
# if type psplash-write >/dev/null >&; then
# TMPDIR=/mnt/.psplash psplash-write "QUIT" || true
# umount /mnt/.psplash
# fi
fi

OK335xS psplash 进度条工作原理 hacking的更多相关文章

  1. ajax ----进度条的原理

    一.进度条的原理 新知识点:Html5中FormData,xmlHttpRequest中的upload属性,progress事件监控 xmlHttpRequest中的upload属性,实现: < ...

  2. HTML5-svg圆形饼状图进度条实现原理

    <svg width="440" height="440" viewbox="0 0 440 440"> <circle ...

  3. php实现进度条原理

    PHP实现进度条的原理: 模版替换,在页面设置一个标识,轮子自己的页面,不发请求给服务器,由服务器端获得进度,然后替换该页面标识,达到进度条效果. 页面代码: 1 2 3 4 5 6 7 8 9 10 ...

  4. PHP上传实现进度条

    Web上传文件的三种解决方案

  5. ASP.NET技巧:教你制做Web实时进度条

    网上已经有很多Web进度条的例子,但是很多都是估算时间,不能正真反应任务的真实进度.我自己结合多线程和ShowModalDialog制做了 一个实时进度条,原理很简单:使用线程开始长时间的任务,定义一 ...

  6. 详解Bootstrap进度条组件

    在网页中,进度条的效果并不少见,如:平分系统.加载状态等,进度条组件使用了css3的transition和animation属性来完成一些特效,这些特效在IE9及IE9以下版本.Firefox的老版本 ...

  7. iOS 开发技巧-制作环形进度条

    有几篇博客写到了怎么实现环形进度条,大多是使用Core Graph来实现,实现比较麻烦且效率略低,只是一个小小的进度条而已,我们当然是用最简单而且效率高的方式来实现. 先看一下这篇博客,博客地址:ht ...

  8. iOS一分钟学会环形进度条

    有几篇博客写到了怎么实现环形进度条,大多是使用Core Graph来实现,实现比较麻烦且效率略低,只是一个小小的进度条而已,我们当然是用最简单而且效率高的方式来实现.先看一下这篇博客,博客地址:htt ...

  9. 制作进度条(UISlider)

    怎样判断是否应当使用进度条 用进度条的主要目的是为了用一根管子的充满程度来直观地表示某种数值的百分比,进度条分为可拖动和不可拖动两种. 可拖动进度条和不可拖动进度条的原理几乎是一模一样,唯一的区别是可 ...

随机推荐

  1. Codeforces Round #343 (Div. 2) C. Famil Door and Brackets

    题目链接: http://codeforces.com/contest/629/problem/C 题意: 长度为n的括号,已经知道的部分的长度为m,现在其前面和后面补充‘(',或')',使得其长度为 ...

  2. 阿里云ubuntu12.04下安装使用mongodb

    阿里云ubuntu12.04下安装mongodb   apt-get install mongodb 阿里云ubuntu12.04下卸载mongodb,同时删除配置文件     apt-get pur ...

  3. BitNami一键安装Redmine(转)

    1. 简介 对于一个新手,如果严格按照官方文档来安装redmine,我想会“疯”掉的.有没有一种简便的方法.有滴,那就是BitNami. BitNami提供redmine的一键安装程序,简单.易用.方 ...

  4. json 基础

    json格式 JSON格式:http://www.json.org/ python和JSON的关系请参考:http://docs.python.org/library/json.html JSON建构 ...

  5. c# Invoke和BeginInvoke 区别

    原文:http://www.cnblogs.com/mashang/archive/2009/08/01/1536730.html Control.Invoke 方法 (Delegate) :在拥有此 ...

  6. POJ 2253 Frogger(floyd)

    http://poj.org/problem?id=2253 题意 : 题目是说,有这样一只青蛙Freddy,他在一块石头上,他呢注意到青蛙Fiona在另一块石头上,想去拜访,但是两块石头太远了,所以 ...

  7. AutoEventWireup解释

    这一事件聚合了当前页是否自动关联某些特殊事件. 首先,从浏览器页面出发的事件不能立刻在本地得到处理,而是POST至服务器上,因此,asp.net建立了委托(代理)机制.在建立一个事件的同事,建立相应的 ...

  8. [topcoder]HappyLetterDiv2

    http://community.topcoder.com/stat?c=problem_statement&pm=13245 就是有字符串,里面的字符可以随意两两消除,如果不等的话,那么最后 ...

  9. MyBatis,动态传入表名,字段名的解决办法

    转载:http://luoyu-ds.iteye.com/blog/1517607 今天做项目,遇到的问题就是需求修改数据表的记录,而且字段名都不是固定的,也就是说是需要通过参数传入的, 本来这也不是 ...

  10. SQL Server Profiler监控SQL Server性能

    全面掌握SQL Server Profiler 1.       原理与相关概念介绍 SQL Server Profiler,大家已经非常熟悉.常常在性能优化中使用,本文档详细介绍SQL Server ...