OS第1次实验报告：熟悉使用Linux命令和剖析ps命令
- 姓名：张一鸣
- 学号：201821121050
- 班级：计算1812
1. 实验环境介绍
实验环境：
- 操作系统：Microsoft Windows 10
- 平台： Cygwin
2. 常用命令使用
- man
- help
3. 剖析ps命令
(1) man ps
NAME
ps — report process status
SYNOPSIS
ps [−aA] [−defl] [−g grouplist] [−G grouplist]
[−n namelist] [−o format]... [−p proclist] [−t termlist]
[−u userlist] [−U userlist]
OPTIONS The ps utility shall conform to the Base Definitions volume of POSIX.1‐2008, Section 12.2, Utility Syntax Guidelines. The following options shall be supported: −a Write information for all processes associated with termi‐ nals. Implementations may omit session leaders from this list. −A Write information for all processes. −d Write information for all processes, except session leaders. −e Write information for all processes. (Equivalent to −A.) −f Generate a full listing. (See the STDOUT section for the contents of a full listing.) −g grouplist Write information for processes whose session leaders are given in grouplist. The application shall ensure that the grouplist is a single argument in the form of a <blank> or <comma>-separated list. −G grouplist Write information for processes whose real group ID numbers are given in grouplist. The application shall ensure that the grouplist is a single argument in the form of a <blank> or <comma>-separated list. −l Generate a long listing. (See STDOUT for the contents of a long listing.) −n namelist Specify the name of an alternative system namelist file in place of the default. The name of the default file and the format of a namelist file are unspecified. −o format Write information according to the format specification given in format. This is fully described in the STDOUT section. Multiple −o options can be specified; the format specifica‐ tion shall be interpreted as the <space>-separated concate‐ nation of all the format option-arguments. −p proclist Write information for processes whose process ID numbers are given in proclist. The application shall ensure that the proclist is a single argument in the form of a <blank> or <comma>-separated list. −t termlist Write information for processes associated with terminals given in termlist. The application shall ensure that the termlist is a single argument in the form of a <blank> or <comma>-separated list. Terminal identifiers shall be given in an implementation-defined format. On XSI-conformant sys‐ tems, they shall be given in one of two forms: the device's filename (for example, tty04) or, if the device's filename starts with tty, just the identifier following the characters tty (for example, "04"). −u userlist Write information for processes whose user ID numbers or lo‐ gin names are given in userlist. The application shall en‐ sure that the userlist is a single argument in the form of a <blank> or <comma>-separated list. In the listing, the nu‐ merical user ID shall be written unless the −f option is used, in which case the login name shall be written. −U userlist Write information for processes whose real user ID numbers or login names are given in userlist. The application shall ensure that the userlist is a single argument in the form of a <blank> or <comma>-separated list.
（2）运行并解释ps命令参数：
运行ps
运行ps -ef
参数的含义:
-e即显示有关用户进程的信息，包括那些没有控制终端的进程
-f显示用户id，进程id，父进程id，最近CPU使用情况，进程开始时间等等
每个字段的含义:
UID ：用户ID
PID ：程序的 ID
PPID ：上级父程序的ID
STIME ：系统启动时间
TTY ：登入者的终端机位置
CMD ：所下达的指令
运行ps aux
参数的含义:
a显示现行终端机下的所有程序，包括其他用户的程序
u以用户为主的格式来显示程序状况
x显示所有程序，不以终端机来区分
每个字段的含义：
PGID：进程组ID
WINPID：windows下的PID规则
4. 通过该实验产生新的疑问及解答
一开始我的用户名为asus，我百度了好久也没找到改名的方法，之后通过同学的帮助，在cygwin输入一串代码，并在目录下找到passwd文件，成功改名。
后来在做打印man ps目录的时候，显示无此手册，我重新安装man包也没法实现，最后在同学的解答下安装了一个新的包取代原来的man包，解决了问题。
