Binary CipherMessage Queues-Unix System-V messages
A message queue is a linked list of messages stored within the kernel and identified by a message queue identifier. Generally message queue is called a queue and its identifier a queue ID. There…
Category Unix
UNIX Process and Signals
Process: A process is an instance of running a program. Kernel is responsible for most of all processes. Process is viewed by kernel and runs in its own address space. It is divided into three segments: Instruction or Text segment…
Unix standard I/O
Standard I/O: All the I/O routines centered around file descriptors. When a file is opened, a file descriptor is returned, and that descriptor is then used for all subsequent I/O operations. With the standard I/O library, the discussion centers around…
Unix Files
Unix File Structure: File: The file is a container for storing information. As a first approximation, we can treat it simply as a sequence of characters. If you name a file foo and write three characters a, b and c…
WORKING WITH BOURNE SHELL
Introduction: Why shell programming? A working knowledge of shell scripting is essential to everyone wishing to become reasonably adept at system administration, even if they do not anticipate ever having to actually write a script. When a Linux machine…
Text processing utilities and backup utilities of unix
Text processing utilities: Cat: The cat command reads one or more files and prints them to standard output. The operator > can be used to combine multiple files into one. The operator >> can be used to append to an…
Basics of Unix
Unix PROGRAMMING Introduction to Unix: Unix is a multitasking, multi-user computer operating system originally developed in 1969 by a group of AT&T employees at Bell Labs, including Ken Thompson, Dennis Ritchie, Brian Kernighan, Douglas McIlroy, and Joe Ossanna. The Unix operating system was first developed in assembly language, but by 1973 had…
Unix Shell Commands
Introduction The purpose of this document is to provide the reader with a fast and simple introduction to using the Linux command shell and some of its basic utilities. It is assumed that the reader has zero or very limited…