FreeBSD command

http://ws.edu.isoc.org/workshops/2006/ccTLD-Samoa/day1/freebsd/freebsdref-1up.pdf


基本知識

~
~/
home directory
使用者的家目錄
一登入就會進入的目錄

../
上一層資料夾

./
現在的資料夾

====================================
Getting out of trouble

^C (Ctrl-C)
    停止正在執行的command

^U  (Ctrl-U)
    清除該行

exit
logout
    Exit from the shell

ESC :q! ENTER
    Quit from vi without saving

===================================================
查找指令的詳細用法

man cmd
man 5 cmd
man -a cmd
    Show manual page for command "cmd".
    c的function也能查
    If a page with the same name exists in multiple sections,
    you can give the section number,
    or -a to show pages from all sections.

=================================================
System status

date
    顯示當前日期時刻

uptime
    顯示最後一次開機到現在的時間 和 load stats

who
w
    顯示誰在系統上
    正在做什麼

============================================================
目錄 資料夾

pwd
    Show current directory ("print working directory")

Change current directory:

cd subdir
    Move into a subdirectory of the current directory

cd ..
    Move up one level, to the parent directory

cd /
cd /absolute/path
    to the filesystem root, 到根目錄
    to an absolute location, 從根目錄開始算的絕對路徑
cd ~username
cd
cd ~
cd ~/
    to a particular user's home directory, 到user家目錄
    or to your own home directory

ls
ls path
    List contents of current directory or given directory
    list
    可以列出 當前資料夾 或 你給的資料夾(path為資料夾路徑) 的內容物
    藍:資料夾
    綠:執行檔
    白:一般文件

ls -a
    List all files, including hidden files   
    檔名第一個字母是'.'就是隱藏檔

ls -d
    List directory itself, rather than its contents

ls -l
    List directory in long form (lowercase 'L', not number one)
    Show  permissions  on  file or directory.
       ,------- type (-=file, d=directory)
      / ,------ rwx perms for user (owner)
     / /  ,---- rwx perms for group
    / /  /  ,-- rwx perms for other
    -rwxrwxrwx
    For a file:
        r allows read; 
        w allows write/append; 
        x allows execute.
    For a directory:
        r allows listing  contents; 
        w allows creation  or deletion of files within  directory;
        x allows directory  to be  entered

ls -ld
ls -ld path
    -l 加上 -d
    好像可以看到自己家目錄的容量上限512，但單位不明

mkdir path
    Create a directory

rmdir path
    Delete an empty directory

rm -rf subdir
    等於-r -f
    Recursively delete a directory and all its contents - DANGEROUS!

rm -r subdir
    移除資料夾
    於上面的差別是?

===============================================================
檔案

rm filename
    Delete (remove) file

cp filename newname
    Copy one file

cp file1 file2 ... subdir/   
    Copy a file or files into another directory.
    (The trailing slash on the subdir is not essential,
    but prevents errors when you are copying
    one file and 'subdir' does not exist)

mv oldname newname
    Rename one file or directory
    ex. mv test.txt ./test.txt

mv file1 file2 ... subdir/
    Move a file or files into another directory

ln -s path newname
    Make  newname  a symbolic or soft link  pointing  to path , which  may
    be  a file or directory  and  can  be  anywhere  on  the  filesystem.

=======================================
搜尋檔案

locate str
    Search  for filenames  matching  str in the  locate  database

find path -type f
    Find  all files under  the  given  path  (use  "." for current  directory)

find path -type f -name 'foo*'
    Find  all files under  the  given  path  whose  name  begins  "foo"

find path -type f | xargs cmd
    Find  all files under  path  and  apply cmd  to  each  of them

find path -type f -print0 | xargs -0 cmd
    Safer version  of above  (works with  filenames  that  contain  spaces)

===================================================================================
Processes

ps auxw
    Show  all processes

ps auxw | grep procname
    Show  all processes  matching  pattern  "procname" 
    (note  that  "grep procname"  itself may  be  shown)

top
    Show  continuously  the  most  active  processes  (q to quit)
    可以看哪個程序最耗CPU

=======================================
Shell facilities

which foo
    Search  for command   foo in PATH and  show  where  it was found

history
history 20
    顯示所有輸入過的指令
    顯示最近輸入的20個指令

↑(方向鍵 上)
    顯示之前輸入過的指令

!num
    Re-execute  command  num  from  history

cmd1; cmd2
    Run  cmd1  followed  by cmd2

cmd1 && cmd2
    Run  cmd1 , then  cmd2  only if cmd1  was successful ($? = 0)

clear
cls
    清螢幕

=======================================================================
Job control

^C  (Ctrl-C)
    停止正在前景執行的command

^Z  (Ctrl-Z)
    Suspend  current  foreground  process  (makes  suspended  job)
    把正在前景執行的command掛在背景裡
    暫緩執行

jobs
    List jobs  under  this  shell

kill %n
    Terminate  job number  n

fg
fg %n
    Restart  suspended  process  in foreground

bg
bg %n
    Restart  suspended  process  in background

cmd &
    Start  command  as background  job

=======================================
File redirection

^D  (Ctrl-D)
    Send  end- of-file on  standard  input

cmd1 | cmd2
    Pipe  output  of cmd1  to input  of cmd2

cmd >out.txt
    Redirect  command  standard  output  to file

cmd 2>err.txt            [sh]     
    Redirect  command  error  output  to file

cmd >out.txt 2>&1        [sh]

cmd >&out.txt            [csh]
    Redirect  both  standard  and  error  output  to file

cmd >>out.txt
    Append  to out.txt  instead  of replacing  it

cmd <in.txt
    Redirect  command  standard  input  from  file

=========================================================
編輯 閱讀

cat > filename
????內容???
???內容?????^D
    建立檔案
    輸入內容
    輸入內容 ctrl+d 編輯結束

cat ????.???
    開啟檔案，閱讀?

其他的，就問男人吧XD

more

less

ee

vi