Modern Operating Systems 笔记 - Processes

操作系统 进程 Unix Windows fork kill sed

pseudoparallelism

The illusion of parallelism while CPU is switching from process to process quickly.

The Process Model

process is an instance of an executing program, is the activity of a program.

If a program is running twice, it counts as two processes.

Process Creation

Processes are created when

  1. System init
  2. Process creation system call by a running process
  3. A user request to create a new process.
  4. Init of a batch job.

Modern Operating Systems 笔记 - Introduction

Unix Windows 操作系统

What is OS

  1. extendes machines : providing programmers(and programs) a clean abstract set of resources instead of the messy hardware
  2. resource manager : managing hardware resources

History of OS

The first digital computer was designed by Charles Babbage. Ada Lovelace was the first programmer(hired by Babbage).

1st Generation Vacuum Tubes

  • The first functioning digital computer, by John Atanasoff and Clifford Berry, Iowa State University.
  • Z3, Konrad Zuse, Berlin.
  • Colossus, a group at Bletchey Park, England
  • Mark I, Howard Aiken, Harvard
  • ENIAC, William Mauchley and J. Presper Eckert, University of Pennsylvania

Vim初级:配置和使用

Vim-Practice Bash Unix Vim sed 编译

Vim是从vi发展出来的一个文本编辑器。代码补全、编译及错误跳转等方便编程的功能特别丰富,在程序员中被广泛使用。和Emacs并列成为类Unix系统用户最喜欢的编辑器。

文档参见:http://vimdoc.sourceforge.net/htmldoc/

中文文档:http://vimcdoc.sourceforge.net/doc/

Makefile 批量更新缩略图

Linux Makefile Unix

背景

网站中通常会产生大量的多媒体文件,尤其是图片。维护和更新这些文件却是很繁琐的事情。本文介绍如何批量地更新用于web的缩略图:采用 ImageMagick + Makefile 的方式,既能及时地更新缩略图,又避免了不必要的文件操作。

  • ImageMagick:是一款命令行图片处理工具,其功能复杂强大,毫不逊色于Ps。在Linux服务器中,通常采用 ImageMagick 来进行web后台的图片操作。
  • Makefile:在 Unix 系统中,通常用 make 来自动化建构软件。make 根据依赖文件的修改时间进行判断是否执行更新,避免了不必要的更新操作。

导航: 上一页 下一页

🔝