What is Linux etc

What is Linux etc

Linux etc is used to store the main configuration files of the system, such as user account and password files, various services Start files, etc. Generally speaking, the attributes of each file in this directory are and can be viewed by ordinary users, but only root has the right to modify them.

Extended information

1./etc/passwd user database, the fields in which give the user name, real name, home directory, Encrypted password and other user information.

2. /etc/mtab is a list of currently installed file systems, initialized by scripts and automatically updated by the mount command. Used when a list of currently installed file systems is required. , such as df command.

3. /etc/shadow Shadow password file on a system with shadow password software installed. The shadow password file moves the encrypted passwords in the /etc/passwd file to /etc/shadow, which only Readable by root, which makes deciphering passwords more difficult.

4. /etc/securetty Confirm the secure terminal, that is, which terminal allows root login. Generally, only the virtual console is listed, so that it is impossible to break into the system through modem or network and obtain super user privileges.

5. /etc/shells lists trusted shells. The chsh command allows users to change the login shell within the scope specified in this file. The service process ftpd that provides FTP service for a machine checks whether the user shell is listed in / etc/shells file, if not, the user will not be allowed to log in.

6. /etc/termcap terminal performance database, explaining what "escape sequence" controls are used by different terminals. When writing a program, do not directly output the escape sequence (which will only work on a specific brand of terminal), but look for the correct sequence for the job to be done from /etc/termcap. In this way, most programs can run on most terminals.

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