Linux File Permission, chmod

Linux File Permission. the chmod permission symbol indicates the meaning of the number r file: readable path: only the path structure list can be read. 4 w files: Writable Path: add, delete, and move files in the path 2x: executable path: enter this path, access the files in this path 1 s suid: only valid for binary files, for example,/usr/bin/passwdsgid: It is effective for files and paths so that files have the permissions of the owner or group for the moment 42 t sbit: it is mainly effective for paths. Only user-created files can be deleted, for example,/tmp/1 main syntax chmod [option] mode [, mode]... file... chmod [option] octal-mode file... mode: You can change the File Permission in two modes. Symbol mode and octal numeric mode. Symbol mode chmod u (owner) g (Group) o (Others) a (all) + (ADD)-(subtract) = (SET) r (readable) w (writable) x (executable) s (suid/sgid) t (sbit) file octal numeric mode suid/sgid/sbit owner group other chomod 0-70-70-70-7filer = 4, w = 2, x = 1, rwx = 7, rw = 6, rx = 5 suid = 4, sgid = 2, sbit = 1 case 1 change file permissions in two modes, turn this file into an executable file, and others cannot modify the Linux code $ chmod 755 ~ /Testfile $ chmod u = rwx, go = rx ~ /Testfile 2: Add writable permissions for all users to the file. Linux code $ chmod a + w ~ /Testfile 3 uses two modes to grant the suid permission to executable files. Linux code $ chmod 4755 ~ /Testfile // The original permission of testfile is 755 $ chomd u + s ~ /Testfile 4 uses two modes to grant the sgid permission to the path. Linux code $ chomd 2755 ~ /Testpath // The original permission of testpath is 755 $ chmod g + s ~ /Testpath/5 in two modes. Add the sbit permission to the path. Linux code $ chmod 1755 ~ /Testpath // The original permission of tsetpath is 755 $ chmod o + t ~ /Testpath