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How do I unzip multiple / many files under Linux?

nixCraft - Sat, 04/19/2025 - 16:35
I have lots of files in a directory called /disk2/images/. All files are in zip file format, so I am using the following command to extract zip files:      unzip *.zip The command result into an error which read as follows:      caution: filename not matched How do I unzip multiple or many zip files under a Linux/Unix-like system? Love this? sudo share_on: Twitter - Facebook - LinkedIn - Whatsapp - Reddit The post How do I unzip multiple / many files under Linux? appeared first on nixCraft. 2024-09-27T19:56:29Z 2024-09-27T19:56:29Z Vivek Gite

Linux / UNIX View Only Configuration File Directives ( Uncommented Lines of a Config File )

nixCraft - Sat, 04/19/2025 - 16:35
Most Linux and UNIX-like system configuration files are documented using comments, but sometimes I just need to see a line of configuration text in a config file. How can I view just the uncommented configuration file directives from squid.conf or httpd.conf file? How can I strip out comments and blank lines on a Linux or Unix-like system? Love this? sudo share_on: Twitter - Facebook - LinkedIn - Whatsapp - Reddit The post Linux / UNIX View Only Configuration File Directives ( Uncommented Lines of a Config File ) appeared first on nixCraft. 2024-09-21T12:33:38Z 2024-09-21T12:33:38Z Vivek Gite

Linux turn OFF password expiration / aging

nixCraft - Sat, 04/19/2025 - 16:35
The /etc/shadow file stores the actual password in encrypted format using a hash (salted) function for the user's account with additional properties related to the user passwords, such as password expiration date or password aging. The /etc/passwd stores usernames and their properties, such as home directory, login shell, and more. The password expiration information for a user is contained in the last six fields. The Linux password expiration for a select user can be disabled by editing the /etc/shadow file. However, I recommend using the chage command for safety reasons. The chage command changes the number of days between password changes and the last password change date. The Linux system uses this information to determine when users must change their passwords. Love this? sudo share_on: Twitter - Facebook - LinkedIn - Whatsapp - Reddit The post Linux turn OFF password expiration / aging appeared first on nixCraft. 2024-09-20T11:46:01Z 2024-09-20T11:46:01Z Vivek Gite

Linux / UNIX: DNS Lookup Command

nixCraft - Sat, 04/19/2025 - 16:35
How do I perform DNS lookup under Linux, UNIX, or Apple macOS (OS X) operating systems without using 3rd party websites for troubleshooting DNS usage? Love this? sudo share_on: Twitter - Facebook - LinkedIn - Whatsapp - Reddit The post Linux / UNIX: DNS Lookup Command appeared first on nixCraft. 2024-09-13T11:37:45Z 2024-09-13T11:37:45Z Vivek Gite

Linux Copy One Hard Disk to Another Using dd Command

nixCraft - Sat, 04/19/2025 - 16:35
How can I copy one hard disk to another using the dd, ddrescue, or dcfldd commands? Love this? sudo share_on: Twitter - Facebook - LinkedIn - Whatsapp - Reddit The post Linux Copy One Hard Disk to Another Using dd Command appeared first on nixCraft. 2024-09-09T20:04:33Z 2024-09-09T20:04:33Z Vivek Gite

Shell script to set up an LXD / Incus (Linux Containers) lab for testing purpose

nixCraft - Sat, 04/19/2025 - 16:35
LXD or Incus is a Linux operating system-level container system. You can build over 25+ Linux distros for testing, fun, and profit. You can even run GUI apps inside those containers and get output displayed back to your X display easily. For example, you can run Firefox in one Linux container for banking needs with custom add-ons, including specific firewall rules just for allowing outgoing banking and nothing else. You can have another container to run Chromium/Edge/FF for social media. Of course, it is not a replacement for something like Qubes OS, but you can do many things in an isolated environment. You can try a new Linux distro without the VM's overheads and test new features offered by that distro. All Linux containers will share the same Linux kernel and hardware devices as your GPU. Here is a quick shell script to build a quick lab to test various Linux distros. Love this? sudo share_on: Twitter - Facebook - LinkedIn - Whatsapp - Reddit The post Shell script to set up an LXD / Incus (Linux Containers) lab for testing purpose appeared first on nixCraft. 2024-08-16T12:06:18Z 2024-08-16T12:06:18Z Vivek Gite

How To check LXD/Incus container BTRFS disk usage on Linux

nixCraft - Sat, 04/19/2025 - 16:35
Here is a quick and dirty shell script I put to check LXD or Incus container size and how much space they are taking on the BTRFS subvolume. Naturally, you must run the script as a root user, and LXD or Icnus must be configured with BTRFS storage backend on Linux operating systems. See how to set up and install LXD on Ubuntu 20.04 LTS or installing Incus on Debian 12/11 using the apt command. Love this? sudo share_on: Twitter - Facebook - LinkedIn - Whatsapp - Reddit The post How To check LXD/Incus container BTRFS disk usage on Linux appeared first on nixCraft. 2024-08-15T21:42:09Z 2024-08-15T21:42:09Z Vivek Gite

Linux shell script to reduce PDF file size

nixCraft - Sat, 04/19/2025 - 16:35
Here is a handy and useful Linux and Unix shell script that reduce PDF file size using Ghostscript. No need to upload your PDF file to the shady third-party website. Just do it from the terminal. I tested it with both CentOS and Ubuntu/Debian Linux. It should work with macOS, FreeBSD and other Unix-like systems as long as you have the Ghostscript installed. Love this? sudo share_on: Twitter - Facebook - LinkedIn - Whatsapp - Reddit The post Linux shell script to reduce PDF file size appeared first on nixCraft. 2024-07-30T22:56:26Z 2024-07-30T22:56:26Z Vivek Gite

How to shutdown FreeBSD laptop when running out of battery power

nixCraft - Sat, 04/19/2025 - 16:35
Email alert example before FreeBSD-based laptop will be shutdown by the script Email alert example before FreeBSD-based laptop will be shutdown by the script Email alert example before FreeBSD-based laptop will be shutdown by the script Email alert example before FreeBSD-based laptop will be shutdown by the script Email alert example before FreeBSD-based laptop will […] Love this? sudo share_on: Twitter - Facebook - LinkedIn - Whatsapp - Reddit The post How to shutdown FreeBSD laptop when running out of battery power appeared first on nixCraft. 2024-07-28T11:28:02Z 2024-07-28T11:28:02Z Vivek Gite

Shell script to see Time-To-Live (TTL) for a DNS record on Linux, Unix, macOS and FreeBSD

nixCraft - Sat, 04/19/2025 - 16:35
TTL is an acronym for Time-To-Live (TTL) in DNS. It sets the time in seconds that a DNS record is allowed to be cached by DNS resolvers (caching server) before it needs to be fetched again from the authoritative name server. In other words, longer TTL can reduce the load on authoritative DNS servers and improve response times by keeping records in the cache longer. The shorter TTL is useful for frequently changing DNS records, as it ensures that updates are propagated quickly across the Internet. Say you want to see the Time-To-Live (TTL) value for a given DNS record for A, AAAA, and MX. Here is a sample shell script that works on Linux, Unix, and macOS. You must have the bash and dig command installed. Love this? sudo share_on: Twitter - Facebook - LinkedIn - Whatsapp - Reddit The post Shell script to see Time-To-Live (TTL) for a DNS record on Linux, Unix, macOS and FreeBSD appeared first on nixCraft. 2024-07-26T18:05:44Z 2024-07-26T18:05:44Z Vivek Gite

How to install and configure sudo on Debian Linux

nixCraft - Sat, 04/19/2025 - 16:35
The minimal version of Debian Linux 12/11 does not support sudo. When performing a network installation for Debian, the usual approach is to use the minimum version, which only installs the essential packages. Most Linux container images based upon Debian also skip sudo, and if your project needs sudo, then read on how to install and configure sudo and grant access to a user on a Debian Linux version 12/11. Love this? sudo share_on: Twitter - Facebook - LinkedIn - Whatsapp - Reddit The post How to install and configure sudo on Debian Linux appeared first on nixCraft. 2024-07-25T23:06:18Z 2024-07-25T23:06:18Z Vivek Gite

Shell script to monitor MariaDB replication and send email alert about server health status

nixCraft - Sat, 04/19/2025 - 16:35
Here is a simple shell script to notify secondary read-only replica (slave) MariaDB server health status failure via email and push notification. Master-slave data replication allows you to copy databases to multiple MariaDB servers. It is useful for backup, data recovery, load balancing, and much more. See how to configure SSL-protected MariaDB replication between a master and slave server. Love this? sudo share_on: Twitter - Facebook - LinkedIn - Whatsapp - Reddit The post Shell script to monitor MariaDB replication and send email alert about server health status appeared first on nixCraft. 2024-07-25T12:51:45Z 2024-07-25T12:51:45Z Vivek Gite

How to install incus server on Debian 12/11

nixCraft - Sat, 04/19/2025 - 16:35
Patreon subscribers can download the PDF version here and support independent content creators. Incus is a free and open-source project for the next-gen container management platform. It is a fork of LXD (the container hypervisor). It can manage both Linux containers and virtual machines. Let us see how to install the stable version of the Incus server on Debian 11 or 12 and deploy both containers and VMs for fun and profit. Love this? sudo share_on: Twitter - Facebook - LinkedIn - Whatsapp - Reddit The post How to install incus server on Debian 12/11 appeared first on nixCraft. 2024-07-23T08:25:44Z 2024-07-23T08:25:44Z Vivek Gite

How to upgrade OpenSUSE 15.5 to 15.6 using the CLI

nixCraft - Sat, 04/19/2025 - 16:35
The most recent release of OpenSUSE Linux, version 15.6 "Leap," is now available. This version incorporates the SUSE Linux Enterprise (SLE) source and community developments, making it the ideal option for a stable Linux experience for users, developers, and system administrators. This page provides instructions on upgrading from OpenSUSE version 15.5 to 15.6 using the command-line interface (CLI). Love this? sudo share_on: Twitter - Facebook - LinkedIn - Whatsapp - Reddit The post How to upgrade OpenSUSE 15.5 to 15.6 using the CLI appeared first on nixCraft. 2024-06-30T11:03:25Z 2024-06-30T11:03:25Z Vivek Gite

lnav – Awesome terminal log file viewer for Linux and Unix

nixCraft - Sat, 04/19/2025 - 16:35
It is no secret that whether you are a developer or sysadmin, you need to use log files to troubleshoot errors on your Linux and Unix systems. You use tools like grep, tail, cat, or journalctl to view log files. However, you may need help with so many log files. These essential Unix tools are suitable for basic text but fall short when dealing with many log files. You can get tired from sifting through endless lines of log files. The lnav utility is here to the rescue! It is a powerful log file viewer that goes beyond the basics. It understands your logs by identifying timestamps, log levels, and other vital details. You can run SQLite SQL queries against your standard log files and build reports for your needs. Let us see how to install and use the lnav tool quickly. Love this? sudo share_on: Twitter - Facebook - LinkedIn - Whatsapp - Reddit The post lnav – Awesome terminal log file viewer for Linux and Unix appeared first on nixCraft. 2024-06-16T11:04:42Z 2024-06-16T11:04:42Z Vivek Gite

How to find out AWS EC2 instances type over SSH

nixCraft - Sat, 04/19/2025 - 16:35
AWS offers various instance types, and sometimes, you need to know which one you are using or which one has been deployed by someone else (another developer or sysadmin) for a project. Don't worry. Here are some commands to find the EC2 instance type over SSH without logging into the AWS console. These commands works with any Linux distro or FreeBSD Unix systems. Love this? sudo share_on: Twitter - Facebook - LinkedIn - Whatsapp - Reddit The post How to find out AWS EC2 instances type over SSH appeared first on nixCraft. 2024-05-26T11:51:12Z 2024-05-26T11:51:12Z Vivek Gite

How to add interface to vnstat to database for monitoring

nixCraft - Sat, 04/19/2025 - 16:35
vnStat is a network traffic monitor for Linux and Unix-like systems. It logs network traffic at different intervals and doesn't require root permissions to run. The implementation involves two commands: vnstat for querying traffic information and vnstatd for data retrieval and storage. Let's see how to add a network interface to vnstat after installation for monitoring purposes. Love this? sudo share_on: Twitter - Facebook - LinkedIn - Whatsapp - Reddit The post How to add interface to vnstat to database for monitoring appeared first on nixCraft. 2024-05-26T05:56:00Z 2024-05-26T05:56:00Z Vivek Gite

sttr – Awesome Linux & Unix tool for transformation of the string

nixCraft - Sat, 04/19/2025 - 16:35
sttr demo The sttr is a free and open-source command-line tool in Golang that lets you easily change and modify text. You can perform transformation operations on the string, such as hashing text, string manipulation, and more. sttr is beneficial for developers and *nix users requiring swift modification to strings or files directly via the command line or TUI. It is helpful in your scripting, data processing, and automation tasks at the CLI. Love this? sudo share_on: Twitter - Facebook - LinkedIn - Whatsapp - Reddit The post sttr – Awesome Linux & Unix tool for transformation of the string appeared first on nixCraft. 2024-05-24T21:17:45Z 2024-05-24T21:17:45Z Vivek Gite

SSH Authentication refused: bad ownership or modes for file /home/user/.ssh/authorized_keys

nixCraft - Sat, 04/19/2025 - 16:35
I'm trying to login using ssh keys but server is only allows to login me using a password. The following message is logged into my Linux or Unix server /var/log/secure or /var/log/auth.log file: Feb 25 06:36:50 ns5 sshd[26681]: Authentication refused: bad ownership or modes for file /home/user/.ssh/authorized_keys2 Here is another message: May 24 18:28:35 ls-www-1 sshd[531320]: Connection closed by 18.1.2.3 port 43640 [preauth] May 24 18:28:44 ls-www-1 sshd[531322]: Authentication refused: bad ownership or modes for file /home/admin/.ssh/authorized_keys May 24 18:28:44 ls-www-1 sshd[531322]: Connection closed by authenticating user admin 18.1.2.3 port 43650 [preauth] How do I fix this problem? Love this? sudo share_on: Twitter - Facebook - LinkedIn - Whatsapp - Reddit The post SSH Authentication refused: bad ownership or modes for file /home/user/.ssh/authorized_keys appeared first on nixCraft. 2024-05-24T19:23:28Z 2024-05-24T19:23:28Z Vivek Gite

How to upgrade Alpine Linux 3.19 to 3.20

nixCraft - Sat, 04/19/2025 - 16:35
I am using Alpine Linux v3.18 or v3.19 with my LXD/Incus server. How do I upgrade Alpine Linux v3.19 to Alpine Linux v3.20? How can I upgrade Alpine Linux v3.18 to Alpine Linux v3.20? Love this? sudo share_on: Twitter - Facebook - LinkedIn - Whatsapp - Reddit The post How to upgrade Alpine Linux 3.19 to 3.20 appeared first on nixCraft. 2024-05-24T11:25:52Z 2024-05-24T11:25:52Z Vivek Gite
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