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2020-09

systems-management

Show all processes

Show all processes To see all the processes, run the ps command with the "-a" option. If you want to see the processes executed by the logged-in user, you can use the "-a" option without any arguments, but if you want to see which processes are being executed by other users, you can use the "-u" option as well.
2020.09.24
systems-managementLinuxTips(RedHat)_en
systems-management

Display processes including their parent-child relationships.

Display processes including their parent-child relationships...
2020.09.24
systems-managementLinuxTips(RedHat)_en
systems-management

Show only running processes and specific processes

Show only running processes and specific processes ●View running processes The ps command basically shows all the processes that are not completed, so it will also show the processes that are stopped. To show only running processes, run the ps command with the option "-r".
2020.09.24
systems-managementLinuxTips(RedHat)_en
systems-management

Display the kill signal

Display the kill signal The kill command not only kills the process, but it can also control various other things. The signals used for this control are called signals, and there are numbers, names, and abbreviations that can be used for control. To check which signals can be used with the kill command, execute the kill command with the option "-l".
2020.09.25
systems-managementLinuxTips(RedHat)_en
systems-management

Shut down the system.

Shut down the system. ●top the system with the halt command There are several ways to stop the system, but executing the halt command will send a system stop message to all connected users, shift the run level to "0", and start the stop process. Normally, you need to be the root user to execute this command, but the halt command can also be executed by a general user. However, when run as a general user, the behavior differs depending on the distribution as follows. RedHat system：Can be executed by general users. However, if the command is executed from a remote host, it will be ignored. Vine Linux system：Ask for the root user's password, and if correct, run the stop process. Debian GNU/Linux system：Cannot be executed by general users Plamo Linux system：Cannot be executed by general users
2020.09.25
systems-managementLinuxTips(RedHat)_en
systems-management

Check your Linux distribution and version.

Check your Linux distribution and version. ●For CentOS7 system [root@Lion ~]# cat /etc/redhat-release CentOS Linux release 7.6.1810 (Core) ●For Fedora systems [root@Lion ~]# cat /etc/fedora-release ●For Ubuntu systems [root@Lion ~]# cat /etc/lsb-release
2020.09.25
systems-managementLinuxTips(RedHat)_en
systems-management

Show loaded kernel modules

Display the loaded kernel modules In order to prevent the kernel from becoming bloated, Linux does not include programs other than those that are minimally necessary for operation in the kernel, but allows them to be added or detached depending on the environment. The things that can be added or detached in this way are called "modules," and typical ones include SCSI adapters, PC cards, and device drivers. The command to display what modules are currently installed is the "lsmod" command. You will need root privileges to execute this command.
2020.09.25
systems-managementLinuxTips(RedHat)_en
systems-management

View detailed information about kernel modules.

View detailed information about kernel modules. To display detailed information about each loaded module, use the modinfo command. Specify the module for which you want to know the detailed information as an argument and execute it.
2020.09.25
systems-managementLinuxTips(RedHat)_en
RPM Package Management

Check the installed RPM packages.

Check the installed RPM packages. Red Hat Enterprise Linux and CentOS, which was developed based on Red Hat Enterprise Linux, use a package management tool called RPM (Redhat Package Manager).。 RPM is a handy management tool that allows you to easily install and uninstall software and manage RPM packages with dependencies in mind, preventing you from accidentally removing RPM packages that you need. If you want to use this RPM, use the "rpm" command. Use the "-q" option to examine the RPM packages already installed, and the "-a" option to list the installed packages. rpm -qa" alone will show you all the packages installed on your Linux system, and is not suitable for checking specific packages. It is not suitable for checking a specific package. To check if a specific package is installed, specify the PRM package you want to check in "rpm -qa".
2020.09.25
RPM Package ManagementLinuxTips(RedHat)_en
RPM Package Management

Display RPM package information

Display RPM package information To find out what features a particular package provides, use the -q option to make a query, and the -i sub-option in combination to display that information. Specify the package name of the package for which you want to display information as an argument.
2020.09.25
RPM Package ManagementLinuxTips(RedHat)_en
RPM Package Management

The directory where the RPM package is installed

Display the directory where the RPM package is installed. To find out where the relevant files are when you install a particular package, run the rpm command with the To check where the related files are located after installing a particular package, run the rpm command with the "-ql" option. Specify the package name as an argument.
2020.09.25
RPM Package ManagementLinuxTips(RedHat)_en
LinuxTips(RedHat)_en

Check which RPM package a particular program is included in.

Check which RPM package a particular program is included in. To check which RPM package a particular program is included in, add the "-qf" option to the rpm command and specify the program (executable file) as an argument. [root@Lion ~]# rpm -qf /usr/sbin/dovecot dovecot-2.2.36-3.el7.x86_64
2020.09.25
LinuxTips(RedHat)_en
RPM Package Management

Test the installation of RPM packages.

Test the installation of RPM packages. Sometimes, due to dependencies, conflicts, or other problems, an error message will be displayed when executing the install command and the installation will fail. It is possible to test for such problems before installation. To do so, run the rpm command with the "--test" option and execute the installation. [root@Lion ~]# rpm -ivh --test zlib-devel-1.2.3-4vl5.i386.rpm ↑Test the installation of the rpm package
2020.09.25
RPM Package ManagementLinuxTips(RedHat)_en
RPM Package Management

Show RPM dependent packages

Show RPM dependent packages Dependencies are often a problem when manipulating packages, such as installing, upgrading, or removing RPM packages. So to avoid these problems, it is important to check the dependencies in advance. To check what package a particular package depends on, run the rpm command with the "-q" option in combination with the "-R" option to display the name of the dependent package.
2020.09.25
RPM Package ManagementLinuxTips(RedHat)_en
RPM Package Management

Install the RPM package

Install the RPM package To install the rpm package, run the ...
2020.09.25
RPM Package ManagementLinuxTips(RedHat)_en
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