Linux Study Notes-document

Linux Study Notes-query the properties of files through ls in files. query non-hidden files by ls. query all files by ls-al. The display structure is as follows: chgrp [-R] group name file name or directory. (Change owner group) chown [-R] Account name: group name file and directory (change owner) chmod permission file or directory (Change permission) in linuxthe File Permission limit can be executed for the permission limit X to decide, Windows is an extension name to decide, .exe ,. bat, com ....... linux permissions are irrelevant to the file name ~ ~. R (reader): Can read files w (writer): Can edit files, modify files, delete files x (execute): Execution files. Permission directory file r can read the directory. If only r does not have w, you cannot enter the directory to read the file content. create a new folder 2. delete a folder 3. change the folder name. modify the folder location 1. you can modify the file name. 2. delete file 3. can I modify attribute x to enter this folder? Can I execute this file and assume that the file has the --- permission, but the directory has the w permission to delete the file? You can delete files by deleting directories. There are two types of permissions: 1. digital code r: 4 (read permission) w: 2 (write permission) x: 1 (Execution permission) If you want rwx permission, 0 indicates -, 4 (4 + 0 + 0) represents r 3 (0 + 2 + 1) represents-wx ....... example: chmod 777 hello. java (the first 7 is the master permission, the second 7 is the group permission, and the third 7 is the other permissions) 2. character code: g (group): group permission. (Chmod g = rwx hello. java) grant rwx permissions o (others): others (chmod o + wx hello. java) Add the wx permission u (user) to others: chmod u-wx hello. java) grant the owner the wx permission a (all): all (chmod) a + r, og + w hello. java adds r permissions to all users and w permissions to the group and others. directory: pwd: display the current Directory cd: 1. cd-(equivalent to the last cd) 2. cd/and directory 3. cd ~ The current user directory 4. cd .. is returned to the upper-level directory (similar to the web directory ../) 5. cd ~ Xieyong enters/home/xieyong mkdir (create directory): 1. mkdir xieyong (create the xieyong directory) 2. mkdir-p xieyong/love/momo (recursively create xieyong/love/momo) 3. mkdir-m 777 xieyong (create the xieyong directory to give the permission 777,-m cannot be used with-p, otherwise it will become invalid) rmdir (delete directory): 1. rmdir xieyong (directly Delete the xieyong directory) 2. rmdir-p xieyong/xieyong (recursive deletion) $ PATH specifies the search address of the command. For example, if ls is placed under bin, path contains:/bin, in this way, the bin will automatically search for ls. Ls (common parameters): ls parameter [file name (current directory by default)] 1. -t dependent time sorting 2. -S file size sorting 3. -R recursive subdirectories are displayed together. 4. -a: Hide directory-. and .. 5. -l show the detailed information package (ll command is equivalent to ls-l) 6. -full -- time display time details, color: directory is generally blue Copy command: cp destination file copied to location 1. -p is assigned together with the archive attribute. 2. -I. If the target file already exists, do you want to overwrite the file? Tip 3. -r recursive replication (the-r option must be used to copy Directories) 4. -l create shortcuts instead of assigning values to this file. -effect of a on-pda 6. -d if the file is a shortcut, assign the shortcut content instead of the shortcut content.