OS第1次实验报告：熟悉使用Linux命令和剖析ps命令
- 姓名：江磊
- 学号：201821121059
- 班级：计算1812
1. 实验环境介绍
给出实验环境：
-
操作系统：Window10（版本： 10.0.18363.657）
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平台：Cygwin
- 用户名：JiangLei
2. 常用命令使用
按照PPT，练习常用命令使用。
3. 剖析ps命令
（1）ps使用方法及参数
PROLOG
This manual page is part of the POSIX Programmer's Manual. The Linux implementation of this interface may differ (consult the corresponding Linux manual page
for details of Linux behavior), or the interface may not be implemented on Linux.
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]
DESCRIPTION
The ps utility shall write information about processes, subject to having appropriate privileges to obtain information about those processes.
By default, ps shall select all processes with the same effective user ID as the current user and the same controlling terminal as the invoker.
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 terminals. 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 ar‐
gument 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 specification shall be interpreted as the <space>-separated concatenation 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 systems,
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 login names are given in userlist. The application shall ensure that the userlist is a sin‐
gle argument in the form of a <blank> or <comma>-separated list. In the listing, the numerical 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.
With the exception of −f, −l, −n namelist, and −o format, all of the options shown are used to select processes. If any are specified, the default list shall be
ignored and ps shall select the processes represented by the inclusive OR of all the selection-criteria options.
（2）运行并解释ps命令参数
①运行ps命令，结果如下：
$ ps
PID PPID PGID WINPID TTY UID STIME COMMAND
1451 1450 1451 8932 pty0 197609 19:58:09 /usr/bin/bash
1473 1451 1473 12360 pty0 197609 20:13:59 /usr/bin/ps
1450 1 1450 11656 ? 197609 19:58:07 /usr/bin/mintty
②运行ps -ef 命令，结果如下：
$ ps -ef
UID PID PPID TTY STIME COMMAND
wangpiji 1474 1451 pty0 20:15:18 /usr/bin/ps
wangpiji 1451 1450 pty0 19:58:09 /usr/bin/bash
wangpiji 1450 1 ? 19:58:07 /usr/bin/mintty
参数含义：
e ：表示显示全部进程
f ：表示完整-格式，包括命令行
③运行ps aux 命令，结果如下：
$ ps aux
PID PPID PGID WINPID TTY UID STIME COMMAND
1451 1450 1451 8932 pty0 197609 19:58:09 /usr/bin/bash
1450 1 1450 11656 ? 197609 19:58:07 /usr/bin/mintty
1475 1451 1475 19468 pty0 197609 20:16:54 /usr/bin/ps
参数含义：
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
（3）字段含义
UID：用户ID
PID：进程ID
PPID：父进程ID
PGID：进程组ID
TTY：终端的次要装置号码
STIME：进程开始时间
COMMAND：所执行的指令
4. 通过该实验产生新的疑问及解答
疑问：在运行man ps命令时。出现“没有ps的手册页条目”的问题。
解答：重新下载man-pages-posix文件夹，重命名位man并替换掉原有的man文件夹。
