The usermod command uses various options to modify the existing user account parameters. The usermod –help command will display the various options that can be used. The syntax of usermod is as follows: $ usermod -[option] [username] Command line options available with the usermod command are as follows: Option Description -a, –append Used with the […]
envsubst: command not found
envsubst substitutes environment variables in a shell string or script. When used with no options, copies stdin to stdout, replacing any environment variable string, such as $VARIABLE or ${VARIABLE}, with the appropriate environment variable value. So, “My editor is $EDITOR” would be converted to “My editor is /usr/bin/emacs.” Specifying a shell format limits the substitutions […]
jlink: command not found
A new tool, called jlink was introduced in Java 9 that enables the creation of modular runtime images. These runtime images are nothing but a collection of a set of modules and their dependencies. A Java enhancement proposal, JEP 220, governs the structure of this runtime image. The JLink tool is designed to provide optional […]
jasmine-node: command not found
Jasmine is an independent unit testing framework for effectively testing JavaScript components in a behavior-driven development architecture. Installing jasmine-node on Unix and Linux First, you need to install the jasmine-node package. Type the following into your terminal: $ sudo npm install -g jasmine-node The -g flag installs jasmine-node on your system globally. Leave the flag […]
nping: command not found
Nping is a utility designed to ease the process of crafting network packets. It is very useful to debug and troubleshoot network communications and perform traffic analysis. For example, if we want to debug certain network connections, we can easily use Nping to determine what’s happening on the wire. The following shows a basic Nping […]
gprof: command not found
The standard GNU profiler, gprof, is available for most Unix-like systems. gprof is part of the GNU toolchain and was one of the earliest open source code-profiling tools. It combines compile-time instrumentation and sampling techniques, using a 100 Hz sample rate. It has the advantage that it does not require kernel support. To prepare a […]
gradle: command not found
Gradle is the newest addition to the Java build project automation tool family. It is open sourced under Apache License 2.0 and its first version (0.7) was released in 2009. Gradle has been gaining a lot of adoption as it draws on lessons learned from other existing build tools such as Ant and Maven. Several […]
netstat: command not found
Network Status (netstat) displays information on the IP configuration of a host but goes further to show its connections, including ports, protocols, and metrics on the communications. The netstat command, known as network statistics, is a versatile command with many features. This command prints network connection details, kernel routing table information, interface statistics, open ports, […]
kubectl: command not found
The Kubernetes command-line tool, kubectl is used to run commands against Kubernetes clusters. You’ll use kubectl to inspect and manage your service’s cluster resources and view logs. Some commonly used commands for retrieving information about a Kubernetes cluster are as follows: kubectl get shows information about the specified API object. kubectl describe gives more detail […]
tvservice: command not found
tvservice command is a part of libraspberrypi-bin package which in turn contains various utilities for interacting with the Raspberry Pi’s VideoCore IV. The RPi video output can be configured using the tvservice application (/opt/vc/bin/tvservice). You should plug the HDMI monitor cable into the RPi and use the tvservice application to list the available modes on […]