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The htop is a CLI utility to check an interactive list of running processes in real-time. It is a more feature-rich and user-friendly alternative to the top command. The htop command allows you to manage system processes, monitor resources, and perform other administration tasks. One of the most prominent features of htop is that it shows color-coded processes, which helps you differentiate them based on resource usage. Furthermore, it lets you customize the results with its sort and filter options. So, this short tutorial is about how to use the htop command in Linux without hassles. Unlike top, the htop command is not preinstalled in most Linux systems. That’s why you must install it using the following commands: Operating System Command Debian/Ubuntu sudo apt-get install htop Fedora sudo dnf install htop RHEL/CentOS sudo yum install htop Now, you can use the htop command, so let’s start with the basics: htop When you execute the above command, it launches the htop utility. Here, you can use the arrow keys to navigate up and down the processes. Moreover, press ‘F1’ or ‘?’ to get the help screen for additional navigation shortcuts. Sort Processes in htop In htop, you can sort the processes by CPU, memory, and other usage. Open the sorting menu by pressing F6: For example, select the PERCENT_CPU option and press ‘Enter.’ As you can see in the above image, all the processes are now sorted by CPU consumption. Search and Filter Processes in htop To search any process in htop, please go through the following steps: Press ‘F3’ to open the search bar. Similarly, press ‘F4’ to filter out the processes. Additional Options with htop -d, –delay=[argument]: By default, htop updates the processes every second, but you can add a delay using this option. For instance, to introduce a delay of 10 seconds, we would enter ‘–delay=10.’ -C, –no-color: This option disables the color output, which is helpful in systems with limited terminal support for colors. -u, –user=[username]: To display the processes for a specific user. Just replace ‘[username]’ with the target user’s name. -p, –pid=[PID1,PID2]: Displays information for specified process IDs. For example, let’s check the details of PID 1: htop -p 1 -v, –version: Prints htop version information. -h, –help: This displays a help message with usage information. Kill a Process in htop If you want to kill any process, select it and press the ‘F9’ key or ‘k’ to transmit a kill signal for the selected process. Wrapping Up Htop is a powerful utility for interactively checking system processes in real time. This tutorial briefly discusses how to use the htop command. As htop is not a preinstalled utility in Linux distributions, your first step is to install it using the mentioned commands. Later, we explained how to sort, search, filter, and kill processes from the htop utility.

All UNIX-based operating systems, including Linux, follow the structure that “everything is a file.” These systems treat all the regular files, directories, processes, symbolic links, and devices like external hardware as files. You can create, modify, and delete files using the commands or from the File Manager. Deleting files is essential when you accidentally create multiple files that become unnecessary for the system. So, in this quick blog, we will explain quick ways to delete a file in Linux with no trouble. There are a few methods of deleting the files, so let’s look at them individually with the correct examples. The rm Command You can use the rm command to delete the file from the terminal. For example, you want to delete the “filename.txt” located in the Downloads directory, so first run the below command to open the directory in the terminal: cd ~/Downloads   Then, use the following command: rm filename.txt The rm command doesn’t display any output, but you can use the -v option to get the output: rm -v filename.txt If you want to delete multiple files from the current directory, you can mention all those files in a single rm command. For example, to delete three files– file1.txt, file2.txt, file3.txt, please run the below command: rm file1.txt file2.txt file3.txt In case you want to delete all the files with the same extension, then you can run the following command: rm *.txt As the above image shows, we have deleted all the .txt files from the Downloads directory. Moreover, you can use multiple extensions in a single command to delete different types of files simultaneously. For example, let’s delete all the files having the .txt and the .sh extensions: rm -v *.sh *.txt Similarly, you can empty a directory by only adding the * in the rm command: rm * Remember, the above command deletes all files except the directories. Hence, if there is a subdirectory, then the terminal will show the following output: However, you can use the -r option with the rm command to delete the subdirectories. The -r option recursively deletes the directory along with its contents: rm -r * In case you want to get the confirmation before deleting the file, please use the -i option. rm -i * Once you run the command, the system will show a confirmation prompt, so all you have to do is press Y to delete or N to decline it. From the File Manager We recommend deleting the file from the File Manager if you are a Linux beginner. So first open the File Manager and locate the directory: Now select the file and right-click it to get the context menu. Finally, click on the Move to Trash option or press Delete button. A Quick Wrap-up Linux has various commands and methods to delete a file quickly. However, users must know how to delete files to maintain an organized system and minimal storage consumption. This quick tutorial explained two ways of doing so. Initially, we discussed how the rm command works, then explained briefly the step-by-step process of deleting files using the GUI.

The Logrotate utility simplifies the process of administering log files. It relocates and replaces log files to manage their size and organize them while maintaining the information present inside them. For example, it will maintain seven log files to keep daily records for seven days. While rotating the log files, Logrotate deletes irrelevant old logs, preventing them from consuming excessive disk space. It runs periodically in the background to keep your systems organized and clean. So, if you want to learn about Logrotate, this blog is for you. Here, we have included in-depth information about how to set Logrotate on Linux. How To Set Logrotate on Linux Although many Linux distributions have Logrotate as the pre-installed utility. However, if your system does not have Logrotate, please use the following command to install it: sudo apt install logrotate Now, let’s move to the configuration part. There are two kinds of logrotate configurations– global and system-specific. Open the ‘/etc/logrotate.conf’ file using a text editor. It is Logrotate’s primary configuration file, and any changes made to it will affect the whole system. sudo nano /etc/logrotate.conf This file has three key sections: To specify the rotation frequency, i.e., the time it should rotate the logs. It is set to weekly by default, but you can change it to daily, weekly, or monthly. To define the number of rotated files it should keep, adjust the value based on how much historical data you want to retain. For instance, ‘rotate 4’ guides it to keep the latest four rotated log files and delete the earlier ones to free up disk space. The third is to specify the permissions and ownership of the new log files it’ll create. You can tweak these settings according to what suits your system best. For instance, to maintain weekly records for one month(28 days), you must enter: weekly rotate 4 create 0644 root root This way, it will rotate one file weekly and keep four such files. Further, it creates a new log file for currently occurring events while giving the root user and group the read-and-write permissions and read-only for others. If you have to monitor a specific application’s logs for underlying issues. In that case, you can tailor log rotation settings for that application by creating its separate logrotate configuration file. Let’s take an example of conda. First, create its file using: sudo nano /etc/logrotate.d/conda In this file, add configurations specific to the conda logs: /var/log/conda/*.log { weekly rotate 4 compress delaycompress missingok notifempty create 0644 root root } Here, the compress command guides to compress the files so that resulting files take up less space. With the delaycompress command, you can hold the latest rotated file uncompressed to make it convenient for the users to refer to it. The missingok option tells logrotate to ignore the absence of a log file and continue its operations without any error. At last, with notifempty, logrotate won’t rotate any empty log file. The logrotate should run automatically as per the default settings. However, you must confirm it using: nano /etc/cron.daily/logrotate A Quick Wrap-up Knowing the configuration process of the logrotate utility is crucial for system administrators and is also essential for disk management in Linux devices. Hence, this blog explains the approaches used to set logrotate on Linux. You can modify configurations globally and simultaneously change them for specific applications. Moreover, system-specific configurations should be used responsibly because they always override global settings.

Cron is a time-based job scheduler that lets you schedule tasks and run scripts periodically at a fixed time, date, or interval. Moreover, these tasks are called cron jobs. With cron jobs, you can efficiently perform repetitive tasks like clearing cache, synchronizing data, system backup and maintenance, etc. These cron jobs also have other features like command automation, which can significantly reduce the chances of human errors. However, many Linux users face multiple issues while setting up a cron job. So, this article provides examples of how to set up a cron job in Linux. How To Set up a Cron Job Firstly, you must know about the crontab file to set up a cron job in Linux. You can access this file to view information about existing cron jobs and edit it to introduce new ones. Before directly opening the crontab file, use the below command to check that your system has the cron utility: sudo apt list cron If it does not provide an output as shown in the given image, install cron using: sudo apt-get install cron -y Now, verify that the cron service is active by using the command as follows: service cron status Once you are done, edit the crontab to start a new cron job: crontab -e The system will ask you to select a particular text editor. For example, we use the nano editor by entering ‘1’ as input. However, you can choose any of the editors because the factor affecting a cron job is its format, which we’ll explain in the next steps. After choosing an editor, the crontab file will open in a new window with basic instructions displayed at the top. Finally, append the following crontab expression in the file: * * * * * /path/script Here, each respective asterisk(*) indicates minutes, hours, daily, weekly, and monthly. This defines every aspect of time so that the cron job can execute smoothly at the scheduled time. Moreover, replace the terms path and script with the path containing the target script and the script’s name, respectively. Time Format to Schedule Cron Jobs As the time format discussed in the above command can be confusing, let’s discuss its format in brief: In the Minutes field, you can enter values in the range 0-59, where 0 and 59 represent the minutes visible on a clock. For an input number, like 9, the job will run at the 9th minute every hour. For Hours, you can input values ranging from 0 to 23. For instance, the value for 2 PM would be ’14.’ The Day of the Month can be anywhere between 1 and 31, where 1 and 31 again indicate the first and last Day of the Month. For value 17, the cron job will run on the 17th Day of every Month. In place of Month, you can enter the range 1 to 12, where 1 means January and 12 means December. The task will be executed only during the Month you specify here. Note: The value ‘*’ means every acceptable value. For example, if ‘*’ is used in place of the minutes’ field, the task will run every minute of the specified hour. For example, below is the expression to schedule a cron job for 9:30 AM every Tuesday: 30 9 * * 2 /path/script For example, to set up a cron job for 5 PM on weekends in April: 0 17 * 4 0,6-7 /path/script As the above command demonstrates, you can use a comma and a dash to provide multiple values in a field. So, the upcoming section will explain the use of various operators in a crontab expression. Arithmetic Operators for Cron Jobs Regardless of your experience in Linux, you’ll often need to automate jobs to run twice a year, thrice a month, and more. In this case, you can use operators to modify a single cron job to run at different times. Dash(-): You can specify a range of values using a dash. For instance, to set up a cron job from 12 AM to 12 PM, you can enter * 0-12 * * * /path/script. Forward Slash(/): A slash helps you divide a field’s acceptable values into multiple values. For example, to make a cron job run quarterly, you’ll enter * * * /3 * /path/script. Comma(,): A comma separates two different values in a single input field. For example, the cron expression for a task to be executed on Mondays and Wednesdays is * * * * 1,3 /path/script. Asterisk(*): As discussed above, the asterisk represents all values the input field accepts. It means an asterisk in place of the Month’s field will schedule a cron job for every Month. Commands to Manage a Cron Job Managing the cron jobs is also an essential aspect. Hence, here are a few commands you can use to list, edit, and delete a cron job: The l option is used to display the list of cron jobs. The r option removes all cron jobs. The e option edits the crontab file. All the users of your system get their separate crontab files. However, you can also perform the above operations on their files by adding their username between the commands– crontab -u username [options]. A Quick Wrap-up Executing repetitive tasks is a time-intensive process that reduces your efficiency as an administrator. Cron jobs let you automate tasks like running a script or commands at a specific time, reducing redundant workload. Hence, this article comprehensively explains how to create a cron job in Linux. Furthermore, we briefed the proper usage of the time format and the arithmetic operators using appropriate examples.

Processes are the running instances of programs that consume system resources. Listing these processes helps you monitor system activity, and troubleshoot issues. That’s why there are multiple tools and utilities in Linux that you can use to list the currently running process. However, many beginners don’t know the exact way to list the process without errors. So, in this short article, we will explain different methods to list the process in Linux. We have divided this section into multiple parts to give you the best commands to list the processes in Linux. The ps Command The ps, or “process status,” is the most common utility to list processes in the terminal: ps -e The -e option guides ps to show every process regardless of whether the user owns those processes. Furthermore, you can customize the ps command to produce additional details using the “aux” options: ps aux The top Command If you desire to view the real-time list of system processes, please use the top command. It continuously updates the process list according to new and completed processes, providing more accurate results: top The above command on execution shows the list of processes as per their CPU consumption. Moreover, You can not interact with the terminal until you press “q” to quit the top utility. The pstree Command The pstree is very different from the above two commands because it displays the hierarchical relationship of processes in a tree-like structure. It helps you visually understand how a process starts and its connection with other active processes. pstree The Glances Tool The Glances tool provides a brief overview of the currently running process. However, you have to install the tool by running the below command: Operating System Command Debian/Ubuntu sudo apt install glances Fedora sudo dnf install glances Arch Linux sudo pacman -Sy glances openSUSE sudo zypper install glances After the successful installation, you can open the Glances by running the following command: glances A Quick Summary Knowing how to list processes can help free up the space and turn off the currently running process. This article covered four ways– the top, ps, pstree, and pgrep commands. You can choose to use any of them according to what suits you best. We recommend you use any commands carefully, or you may get errors.

by: Chris Coyier Thu, 26 Jan 2023 01:30:59 +0000 Stephen and I hop on the podcast to chat about some of our recent tooling, local development, and DevOps work. A little while back, we cleaned up our entire monorepo’s circular dependency problems using Madge and elbow grease. That kind of thing usually isn’t the biggest of deals and the kind of thing a super mature bundler like webpack deals with, but other bundlers might choke on. Later, we learned that we had more dependency issues like inter-package circular dependencies (nothing like production deployments to keep you honest) and used more tooling (shout out npx depcheck) to clean more of it up. Workspaces in a monorepo can also paper over missing dependencies — blech. Another change was moving off using a .dev domain for local development, which oddly actually caused some strange and hard-to-diagnose DNS issues sometimes. We’re on .test now, which should never be a public TLD. Time Jumps 00:26 Dev ops spring cleaning 01:25 Local dev with .dev, wait, no, .test 06:58 Sponsor: Notion 07:54 Circular dependency 11:41 Monorepo update 13:35 Interpackage and unused packages 16:25 TypeScript 17:54 Upgrading packages 20:35 Hierarchy of packages Sponsor: Notion Notion is an amazing collaborative tool that not only helps organize your company’s information but helps with project management as well. We know that all too well here at CodePen, as we use Notion for countless business tasks. Learn more and get started for free at notion.com. Take your first step toward an organized, happier team, today.