Linux命令行和Shell脚本编程

1. variable

2. control flow

3. commands

3.1 how to set your own prompt

　　echo $PS1  -- the default format of your command line prompt

　　echo $PS2  -- the format of the second-tier command line prompt

　　update:

　　PS1="[\t]\$"　　it will show like this:[21:51:22]$

　　(this only apply to the current session)

3.2 using the bash manual

　　man grep

3.3 Make sure the linux uses a virtural directory.(This is not the method used by windows)

　　it uses a single directory called "root"

　　You will notice that linux uses a forward slash(/) instead of a backward slash(\) to denote directories in filepaths.

　　The backward slash denote a escape character.

3.4 traverse directories

　　cd command

　　----------common linux directories name

　　/bin    the binary directory, where many usr-level utilities are stored

　　/etc    the system confiruration file directory

　　/home    the home directory, where linux creates user directories

　　/opt    often used to store optional software packages

　　/sbin    the binary directory, where many admin-level utilities are stored

　　/usr    the user-installed software directory

　　/var    the variable directory, for files that change frequently, such as log file.

3.5 the filter of ls command

　　ls -l *XXX*   can choose the file/directory including XXX

3.6 create file

　　touch

3.7 copy files

　　cp test1 destination

　　(if the destination file exists, the cp command will prompt you to answer whethre or not you want to overwrite it.)

3.8 rename file

　　in linux world, renaming file means moving, use mv command:

　　mv test.txt test1.txt

　　ls -l test*

　　-rwxrwxrwx 1 Administrator None 9 2010-05-29 01:02 test1.txt

　　(Notice that moving the file changes the file name but keep the same inode number and timestamp value.)

3.9 delete files

　　in linux world, delete files means removing, use rm command:

　　rm -i test.txt

　　(Notice that the command prompts you make sure you are serious to delete the file.)

3.10 create/delete directories

　　mkdir/rmdir command

3.11 view file statistic

　　stat test.txt

　　 File: `test.txt'
  Size: 13              Blocks: 1          IO Block: 65536  regular file
　　Device: 601c6e4dh/1612475981d   Inode: 562949953465703  Links: 1
　　Access: (0644/-rw-r--r--)  Uid: (  500/Administrator)   Gid: (  513/    None)
　　Access: 2010-05-29 22:48:27.468750000 +0800
　　Modify: 2010-05-29 22:52:11.015625000 +0800
　　Change: 2010-05-29 22:52:11.015625000 +0800

3.12 view whole file

　　cat/more/less/

3.13 view part of the file

　　tail/head