top is the most popular tool used on UNIX/Linux for monitoring. Today we are going to see another one called its alternative tool htop, which is just reached to version 2.0 and comes with some cool new features.
Htop is an interactive real time process monitoring application for Linux/Unix like systems and also a handy alternative to top command, which is default process monitoring tool that comes with pre-installed on all Linux operating systems.
Htop has numerous other user-friendly features, which are not available under top command and they are:
- In htop you can scroll vertically to view the full process list, and scroll horizontally to view the full command lines.
- It starts very quickly as compared top, because it doesn’t wait to fetch data during startup.
- In htop you can kill more than one processes at once without inserting their PIDs.
- In htop you no longer needed to enter process number or priority value to re-nice a process.
- Press “e” to print the set of environment variables for a process.
- Use mouse to select list items.
More detail you can find in http://hisham.hm/htop/
Install Htop Using Binary Packages in Linux
To install Htop on RHEL 7/6/5 and CentOS 7/6/5, your system must have RepoForge (RPMForge) repository installed and enabled, to do so run the following commands on your respective distributions to install and enable it for your system architecture (32bit or 64bit).
On RHEL/CentOS – 32-bit OS
-------------- For RHEL/CentOS 6 -------------- # wget http://packages.sw.be/rpmforge-release/rpmforge-release-0.5.2-2.el6.rf.i686.rpm # rpm -ihv rpmforge-release-0.5.2-2.el6.rf.i686.rpm -------------- For RHEL/CentOS 5 -------------- # wget http://packages.sw.be/rpmforge-release/rpmforge-release-0.5.2-2.el5.rf.i386.rpm # rpm -ihv rpmforge-release-0.5.2-2.el5.rf.i386.rpm
On RHEL/CentOS – 64-bit OS
-------------- For RHEL/CentOS 7 -------------- # wget http://pkgs.repoforge.org/rpmforge-release/rpmforge-release-0.5.3-1.el7.rf.x86_64.rpm # rpm -ihv rpmforge-release-0.5.3-1.el7.rf.x86_64.rpm -------------- For RHEL/CentOS 6 -------------- # wget http://packages.sw.be/rpmforge-release/rpmforge-release-0.5.2-2.el6.rf.x86_64.rpm # rpm -ihv rpmforge-release-0.5.2-2.el6.rf.x86_64.rpm -------------- For RHEL/CentOS 5 -------------- # wget http://packages.sw.be/rpmforge-release/rpmforge-release-0.5.2-2.el5.rf.x86_64.rpm # rpm -ihv rpmforge-release-0.5.2-2.el5.rf.x86_64.rpm
Once RPMforge repository has been installed, you can hit the following yum command to fetch and install the htop package as shown.
# yum install htop
On Fedora OS
Fedora users can easily install htop using Fedora Extras repository by typing:
# yum install htop # dnf install htop [On Fedora 22+ releases]
On Debian and Ubuntu
In Debian and Ubuntu, you can fetch htop by typing:
# sudo apt-get install htop
Compile and Install Htop from Source Packages
To install Htop 2.0 version, you must have Development Tools and Ncurses installed on your system, to do so run the following series of commands on your respective distributions.
On RHEL/CentOS and Fedora
# yum groupinstall "Development Tools" # yum install ncurses ncurses-devel # wget http://hisham.hm/htop/releases/2.0.0/htop-2.0.0.tar.gz # tar xvfvz htop-2.0.0.tar.gz # cd htop-2.0.0
On Debian and Ubuntu
$ sudo apt-get install build-essential $ sudo apt-get install libncurses5-dev libncursesw5-dev $ wget http://hisham.hm/htop/releases/2.0.0/htop-2.0.0.tar.gz $ tar xvfvz htop-2.0.0.tar.gz $ cd htop-2.0.0
Next, run the configure and make script to install and compile htop.
# ./configure # make # make install
How do I use htop and its Output
htop output consists of three sections
1) header 2) body and 3) footer.
Header displays the following three bars, and few vital system information. You can change any of these from the htop setup menu.
- CPU Usage: Displays the %used in text at the end of the bar. The bar itself will show different colors. Low-priority in blue, normal in green, kernel in red.
- Memory Usage
- Swap Usage
Body displays the list of processes sorted by %CPU usage. Use arrow keys, page up, page down key to scoll the processes.
Footer displays htop menu commands.
Now run the htop monitoring tool by executing following command on the terminal.
Press F2 or S for setup menu > there are four columns i.e Setup, Left Column, Right Column and Available Meters.
Here, you can configure the meters printed at the top of the window, set various display options, select among color patterns and choose which columns are printed in which order.
Display Processes in Tree View – Press F5 or t
Type tree or t to display processes tree view.
You can refer function keys displayed at footer to use this nifty htop application to monitor Linux running processes. However, we advise to use character keys or shortcut keys instead of function keys as it may have mapped with some other functions during secure connection.
Htop Shortcut and Function Keys
Some of the shortcut and function keys and its functionality to interact with htop.
|Shortcut Key||Function Key||Description|
|h||F1||Invoke htop Help|
|S||F2||Htop Setup Menu|
|/||F3||Search for a Process|
|I||F4||Invert Sort Order|
|>||F6||Sort by a column|
|[||F7||Nice – (change priority)|
|]||F8||Nice + (change priority)|
|k||F9||Kill a Process|