In this article, we will see the different ways to add a header record or a trailer record to a file. Let us consider a file, file1. $ cat file1 apple orange grapes banana Adding a line to the start of the file (header) 1. To add a header record using sed: $ sed ‘1i […]
yum: command not found
YUM is the default package management system for CentOS/RHEL and part of its role is to automatically calculate what packages may require updating, what dependencies are required, and to manage the entire process of updating your system in a very simple way. The main configuration file of YUM is /etc/yum.conf, and the main directory, which […]
dpkg-scanpackages: command not found
dpkg-scanpackages utility creates a Packages file from a tree of binary packages. The Packages file is used by dselect to provide a list of packages available for installation. Basically, it is a tool that allows you to convert a directory containing .deb packages into a repository. If you encounter the below error: dpkg-scanpackages: command not […]
virt-sparsify: command not found
libguestfs is a command-line library of utilities for working with VM disks. This library consists of roughly 30 different commands, some of which are included in the following list: guestfish virt-builder virt-builder-repository virt-copy-in virt-copy-out virt-customize virt-df virt-edit virt-filesystems virt-rescue virt-sparsify virt-sysprep virt-v2v virt-p2v If you encounter below error: virt-sparsify: command not found you may try […]
ncview: command not found
Ncview is a visual browser for netCDF format files. Typically you would use ncview to get a quick and easy, push-button look at your netCDF files. You can view simple movies of the data, view along various dimensions, take a look at the actual data values, change color maps, invert the data, etc. It runs […]
update-alternatives: command not found
When you install Java, it usually means one of two things: you are installing the Java Runtime Environment (JRE) or the Java Development Kit (JDK). The JRE provides the runtime that allows you to run Java programs, whereas the JDK contains the JRE, as well as other tools, that allow you to develop in Java. […]
lolcat: command not found
lolcat is a program that concatenates files, or standard input, to standard output (like the generic cat), and adds rainbow coloring to it. In case you encounter the below error: lolcat: command not found you may try installing the below package as per your choice of distribution. Distribution Command OS X brew install lolcat Debian […]
mount.cifs: command not found
SMB, also known sometimes as CIFS, is the protocol in charge of providing shared access to files and printers on Windows networks. To make things simpler we use both terms interchangeably. This service can run directly over TCP port 445, but it can also use the NetBIOS API. The Linux CIFS filesystem is composed of […]
CentOS/RHEL: Mount Command Fails With “mount: does not contain SELinux labels”
The Problem Getting below error message when trying to mount a filesystem: # mount /dev/mapper/vg-lv /mnt mount: /mnt does not contain SELinux labels. You just mounted an file system that supports labels which does not contain labels, onto an SELinux box. It is likely that confined applications will generate AVC messages and not be allowed […]
yum-config-manager: command not found
YUM (short for Yellowdog Updater Modified) is an open source tool that was developed by Red Hat Inc for RPM-based systems. It is a high-level package management tool that’s used for easily installing, removing, updating, or searching software packages on systems or in network repositories. It allows us to use a CentOS base and third-party […]