Linux Reference Note 4

I. Administrative authority and Attribution 1. Permissions Overview Document Attribution owner (U): The user owning this file/directory-user belongs to Group (g): The group that owns this file/directory-group other users (o):-other access rights Read (R) for users other than the owner, the owning group : Allow view content-read write (w): Allow content to be modified-write executable (x): Allow to run and toggle-excute2. View Permissions ls-l # ls-l/etc/passwd-|rw-|r--|r--. 1 root root 2481 February 09:37/etc/passwd①②③④⑤⑥⑦⑧⑨⑩ permissions reading order: ⑩①⑥②⑦③④① file Type-file D directory L link ② owner's permission r = 4 Read W = 2 write x = 1 Executable-No ③ of the owning group R = 4 Read W = 2 write x = 1 executable-no ④ other user's rights R = 4 Read W = 2 write x = 1 executable-no ⑤ link Number file: Number of links Directory: how many subdirectories (. .. ⑥ owner ⑦ The owning group ⑧ file size ⑨ file creation time ⑩ File/directory name 3. change file Attribution # Chown Master: File/directory Change file/directory owner # chown: Genus group File/directory change the owning group of File/directory # Chown owner: Genus group File/directory change text The owner and the owning group of the pieces/directory-R recursive eg:[[email protected] ~]# rm-rf/tmp/*[[email protected] ~]# ls-ld/tmp/studir[[email  protected] ~]# mkdir/tmp/studir[[email protected] ~]# ls-ld/tmp/studir[[email protected] ~]# chown Student/tmp/studir/[[email protected] ~]# ID student[[email protected] ~]# useradd student[[email  Protected] ~]# ID student[[email protected] ~]# chown Student/tmp/studir/[[email protecTed] ~]# ls-ld/tmp/studir[[email protected] ~]# chown:users/tmp/studir/[[email protected] ~]# ls-ld/tmp/st Udir[[email protected] ~]# chown root:root/tmp/studir/[[email protected] ~]# ls-ld/tmp/studir4. Change file/directory Permissions chmod command format: chmod [ugoa][+-=][rwx] Document path ...-r: Recursive modification (with documents in all subdirectories and subdirectories) [[email protected] ~]# ls-ld/tmp/ Studir[[email protected] ~]# chmod g-rx,o-rx/tmp/studir/[[email protected] ~]# ls-ld/tmp/studir[[email  protected] ~]# chmod u-w,g=rx/tmp/studir/[[email protected] ~]# ls-ld/tmp/studir[[email protected] ~ ]# chmod a=rwx/tmp/studir/[[email protected] ~]# Ls-ld/tmp/studir II, Backup and recovery 1. Make/Release Zip package A. Compressed zip format: Zip [-ry] backup file. zip document path ... eg:[[email protected] ~]# ls-ld/boot/[[email protected] ~]# ls /opt/[[email protected] ~]# zip-ry/opt/boot_bak.zip/boot/[[email protected] ~]# LS/OPTB. Decompression format: Unzip backup file. zip [-D destination folder] Format: Unzip backup file. zipeg:[[email protected] ~]# ls/tmp/todir[[email protected] ~]# unzip-d/tmp/todir/opt/boot_bak.zip [[email protected] ~]# Ls/tmp/todir2. Making/Releasing. Tar Package A. Making a. Tar package and compressing the basic usage format: Tar- ZCPF backup files. tar.gz Document Path ... Format: TAR-JCPF backup file. tar.bz2 Document Path ... Format: TAR-JCPF backup file. Tar.xz document Path ... eg:[[email protected] ~]# ls-ld/var/log/[[email protected] ~]# Du-sh/var/lo G/[[email protected] ~]# mkdir-p/tmp/day03[[email protected] ~]# tar-zcpf/tmp/day03/log.tar.gz/var/log/[ [email protected] ~]# tar-jcpf/tmp/day03/log.tar.bz2/var/log/[[email protected] ~]# tar-jcpf/tmp/day03/ Log.tar.xz/var/log/[[email protected] ~]# du-sh/tmp/day03/*b. Extract the basic usage format for the TAR package: TAR-XPF backup file. tar.gz format: TAR-XF Backup files. tar.bz2 format: tar-xf backup file. tar.xz [-C destination Folder]eg:[[email protected] ~]# cd/tmp/day03/[[email protected] day03]# ls[[email protected] day03]# tar-xf log.tar.gz[[email protected] day03]# ls[[email protected] day03]# RM-RF var[[email protected] day03]# ls[[email protected] day03]# tar-xf log.tar.bz2[[email Protected] day03]# ls[[email protected] day03]# rm-rf var[[email protected] day03]# ls[[email  Protected] day03]# tar-xf log.tar.xz[[email protected] day03]# ls[[email protected] day03]# rm-rf var[[email  protected] day03]# LS III, Access CD and ISO image 1. Mount Mount device mount point (must be a directory) 2. Uninstall the Umount device Umount mount point 3. Optical drive devices under Linux/dev/sr0/dev/cdrom experiment: Accessing disc files 1. Insert the ISO file into the CD drive 2. Mount [[email protected] ~]# ls/mnt/dvd[[email  Protected] ~]# mkdir-p/mnt/dvd[[email protected] ~]# ls/mnt/dvd/[[email protected] ~]# mount/dev/cdrom/mnt /dvd/3. Accessing the disc contents [[Email protected] ~]# ls/mnt/dvd/4. Uninstall [[email protected] ~]# umount/mnt/dvd[[email  Protected] ~]# ls/mnt/dvd/

Linux Reference Note 4