Linux Learning Notes

1 Linux Development steps:2 3 1. Enter VI Hello.java4 2. Enter i[into insert mode]5 3. Enter esc[into command mode]6 4. Input: q!"Do not save direct exit": Wq "Exit and save"7 5. Enter LS-L "View detailed list"8 5. Compile javac Hello.java file9 6. Allow Java Hello.classallow class suffixes to be addedTen  One  A Catalogue Details: -  - root directory: Store root user-related files the Home directory: Files related to ordinary users - Bin directory: Store common Command Directory - sbin directory: A directory with certain permissions to use - mnt directory: The directory where the CD-ROM or floppy drive is mounted by default + Boot directory: Store boot-related files - etc Directory: Store configuration-related files + var directory: Store Some frequently changing files A usr directory: default installation folder at  - command: - "show current in that directory" - pwd - "Add user command" -Useradd +User name in "Set Password" -passwd +User Name Note: If you do not add a user name, the current user's password is set to "Delete User" +Userdel +User name -Userdel +xiaoming "Home directory is not deleted" theUserdel-R xiaoming "Delete user and home directory" *  $ operating level:Panax Notoginseng 0: Shut down the machine - 1: Single User the 2: Multi-user status No NETWORK service + 3: Network Service with multi-user status A 4: The system is not used to retain the user the 5: Graphical interface + 6: System Restart -  $ The common RunLevel is 3 and 5, to modify the default run-level modifiable files $ID of/etc/inittab:5: Initdefault: The numbers in this line -  -  the  - Linux Common CommandsWuyi pwd "Show current working directory" the CD "Change Directory" - ls "List files and directories" WuLS-L "Show long list format" -LS-a "Show hidden files" AboutLS-Al $  - mkdir "Create folder" - rmdir "Delete Folder" -  A Touch "Create empty file" + cp "Copy command" theCP-R dir1 Dir2 "Recursive replication mingle (copy subdirectory information)" -  $ mv "Moving files and changing file names" the RM "Delete files and directories" theRM-RF *"Delete all content (including directories and files) R recursive F mandatory" the  the Ln "Establishing Symbolic Links" -LN-s Source Target inLn-s/etc/inittab Inittab "Inittab pointing to the actual file/etc/Inittab " the  the More "Show file contents, with pagination" About Less "show file contents with pagination" the grep "Querying content in text" theL "Pipe Command" NOTE: in Linux and UNIX systems |is the pipe command.  the How to understand +Give the result of the previous command |Command handling after command -  the Bayi Find search files and directories the  the REDIRECT command (check Baidu) -LS-| >a.txt List Contents write to file A.txt (blanket write) -Ls-al >> Aa.txt The contents of the list are appended to the end of the Aa.txt file to enter information from the file Database_program<database_data

Linux Learning Notes