curso ccna 200 301

curso ccna 200 301.9.5 Symbolic links 367 Commands with superuser privileges. The difference between the SU and sudo commands is that after entering sudo, the system prompts for this user's password instead of the superuser's password.Note: Administrators should be careful when granting superuser and root-level access privileges. All processes (including background daemons) should only have the minimum privileges needed to complete their tasks successfully. Giving too much access to a process can lead to a significant risk of an attack where an attacker could gain full access to the system.Important concepts related to permissions are shown below. File permissions can be used to restrict access to a file or directory to the file owner, users belonging to the file's attribute group, and all other % users.Access to a file or directory can be modified by executing the chmod command. Read permissions (r) = 4, write permissions (w) = 2, and execute permissions (x) = 1. Groups involve a collection of permissions for one or more users grouped together.The chgrp command can be executed to change the group of a file.The chown command can be executed to change the owner of a file.UNIX file permissions are passed "top-down," meaning that not having access to a directory automatically means that you lose access to all its subdirectories and files. Superuser privileges are the highest level of access and should only be used in special circumstances (for example, to perform administrative(Used when tasks are performed). All processes (including background daemons) should only have the minimum privileges required to complete the task successfully.9.5 Symbolic Links The topic covered in this section is how to link files together. Like normal links, symbolic links (abbreviated symlink, sometimes called softlinks) give files an "alias". In a directory listing, a normal link is a record with the content "filename + pointer", while a symbolic link is a specially marked file containing the name of another file or directory (that is, a symbolic link corresponds to a record in a directory with the content "filename + pointer A symbolic link corresponds to a record in a directory whose contents are "filename + pointer", and the pointer points to a file whose contents are a string of another filename). The so-called "other file or directory" is often referred to as the target of the symbolic link, and people generally say that the symbolic link "points to" or "references" the target file. In short, a symbolic link contains the name of another file and does not contain actual data. From a command (execution) point of view, a symbolic link is no different from a standard file, but when it is referenced, it all points to the target of the symbolic link. Let's look at an example of creating a file. Example 9.3 shows the echo command being executed to save a line of lyrics by Vanilla Ice (an American rapper) to a file called filel. The contents of this file can be viewed by executing the cat command. After the file filel is created, execute the command In -s /tmp/file.l / tmp / file.2 to create the symbolic link fHe.2 to file.l. Finally, execute the command Is -al / tmp / file * to verify that those two files exist.