OS第1次实验报告：熟悉使用Linux命令和剖析ps命令

1. 实验环境介绍

• 操作系统：Microsoft Windows [版本 10.0.18362.657]
• 平台：Cygwin
• 用户名：LiYao

2. 常用命令使用

3. 剖析ps命令

(1)运行man ps:

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 pro‐
       cesses.

       By default, ps shall select all processes with the same effective  user
       ID  as  the  current user and the same controlling terminal as the in‐
       voker.

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ps -ef命令

解释命令中参数的含义：

-e：显示系统所有进程信息

-f：显示UID,PPIP,C与STIME栏位。

解释返回结果每个字段的含义：

UID：用户ID
PID：进程ID
PPID：父进程ID
C: CPU使用的资源百分比
STIME：系统启动时间
TTY：登入者的终端机位置
COMMAND：所下达的指令

(3)运行ps -aux命令

 解释命令中参数的含义：

-a：显示现行终端机下的所有进程，包括其他用户的进程；
-u：以用户为主的进程状态 ；
-x：通常与 a 这个参数一起使用，可列出较完整信息。

4. 通过该实验产生新的疑问及解答

(1)关于如何修改用户名为自己名字的拼音

使用写字板或其他文本编辑器打开cygwin目录下的/etc/passwd文件；

刚开始找不到passwd文件，需要使用用mkpasswd -l > /etc/passwd 语句创建，然后再更改用户名为自己名字的拼音；

接着在home目录下建立相应的名字拼音。这样用户名就修改好了。