Windows and Linux Real time scenarios and answers that Works

What is Docker ? Docker is a software technology providing operating-system-level virtualization also known as containers, promoted by the company Docker, Inc. Docker provides an additional layer of abstraction and automation of operating-system-level virtualization on Windows and Linux . Docker uses the resource isolation features of the Linux kernel such as cgroups and kernel namespaces , and a union-capable file system such as OverlayFS and others to allow independent "containers" to run within a single Linux instance, avoiding the overhead of starting and maintaining virtual machines (VMs).  If Virtual Machines are hardware virtualization then containers are os virtualization.  We don't need a real OS in the container to install our application. Applications inside the container are dependent on HOST OS kernel where its running. For example if we hosted java application like inside the container it will use all the java libraries and config files fro...

1)HCL Python scripting developer Interview questions:- 1) How do you check list of files in the given path in python ?? 2) How do you check whether file is exist or not in python 3) How do you perform copy file cmd in python ?? 4) What is d use of setup.py in python 5) What is d use of __init__=__main__: condition in python?? 6) What is d type of *args and **kargs ?? 7) sys.path use in python ??   2) CES Limited Python developer Interview Face2Face Interview questions:- 1.Basic questions on oops:   *.Implement Base class using Instance, static and Abstract method     instance method - takes two arguments to add operation     static method - takes two args to multiply operation     abstract method - takes two args to div operation   *. Implement child class using 3 instance methods     instance - takes three args for add operation     instance - takes two args for...

/bin This directory contains executable programs which are needed in single user mode and to bring the system up or repair it. /sbin Like /bin, this directory holds commands needed to boot the system, but which are usually not executed by normal users. /usr/bin This is the primary directory for executable programs. Most programs executed by normal users which are not needed for booting or for repairing the system and which are not installed locally should be placed in this directory. /usr/local This is where programs which are local to the site typically go. /usr/local/bin Binaries for programs local to the site. /usr/local/sbin Locally installed programs for system administration.

When the Linux system boots up you get a console similar to below, machine_name login: This prompt is generated by a program called  getty  which is regenerated every time when an incorrect  password  is provided, by the init process which is again created by  fork  function. NOTE:   Fork  is a function which creates a new process by duplicating the calling process. The new process, referred to as the child, is an exact duplicate of the calling process, referred to as the parent. To be brief the Linux login works as per the below steps Getty  process presents the login prompt to the user console Once the username is provided, the password is validated and if successful the user is allowed to login into the shell If there is a failure getty process is re-initiated by the fork function and the password prompt re-appears. The maximum number of failure attempts would be allowed as defined under the pam configur...