cours ccna v5 pdf

cours ccna v5 pdf.chmod a=rwx file.txt is equivalent to chmod 777 file.txt and is also equivalent to rwxrwxrwxchmod o= file.txt is the same as chmod 770 file.txt and is also equal to -rxrwx-chmod g=w file.txt is the same as chmod 740 file.txt and is also equal to -rwx-w-chmod g+x file.txt is the same as chmod 754 and is also equal to -rwxr-xr-chmod o-r file.txt is the same as chmod 750 file.txt and is also equal to -rwxr-x-For all the examples in this section, the chmod command is executed in the same directory as the file it is manipulating. To use chmod to change the permissions of a file in a different directory, you can specify the specific file by means of an absolute path (for example, chmod 770 directory/file.txt), letting the command know where the file is located.Note: In order to access a directory, you must at least have execute (X) permissions for that directory. If you do not have any permissions, you will not be able to access the directory.UNIX file permissions are passed "top-down", which means that if you do not have access to a directory, you automatically lose access to all its subdirectories and files. For example, the directory FILE_D has the permissions drwxm, and its subdirectory SUBFILE_D has the permissions dnvxr.xr.x. Suppose you need to modify the access rights to the directory FILE_D to take away the read, write and execute permissions from the users belonging to its group and all other users, but without affecting any access rights of the owner of FILE_D. To do this, execute the chmodgo-rwxFILE_D command, g. -rwx means that all access rights to FILE_D are withdrawn from users belonging to the FILE_D group and all other users. Once this command is executed, it affects the access rights of SUBFILE_D, a subdirectory of FILE_D, even if the access rights of SUBFILE_D are drwxr-xr-x0, which means that users belonging to the SUBFILE_D group and all other users cannot access SUBFILE_D, which is attributed to the access rights setting of its parent directory FOLD_D. which is passed down to the subdirectory SUBFILE_D.The same concept applies in reverse, that is, if users belonging to the SUBFILE_D group and all otherThat is, if access rights to SUBFILE_D are assigned to users belonging to the SUBFILE_D group and all other users, such rights settings will not be uploaded to FILE_D.