Lecture 2
... • A key concept of operating systems is multiprogramming. – Goal of multiprogramming is to efficiently utilize all of the computing resources. – When a job issues an I/O request (e.g., open a file, read data from a file), it cannot continue until the request is fulfilled. – The CPU then becomes idle ...
... • A key concept of operating systems is multiprogramming. – Goal of multiprogramming is to efficiently utilize all of the computing resources. – When a job issues an I/O request (e.g., open a file, read data from a file), it cannot continue until the request is fulfilled. – The CPU then becomes idle ...
file - ScholarSphere
... Do they require users to utilize complex passwords; how frequently are users required to change passwords; how often can a previous password be reused Do they have anti-virus software installed on all users’ computers; on all file servers; how frequently do they update anti-virus ...
... Do they require users to utilize complex passwords; how frequently are users required to change passwords; how often can a previous password be reused Do they have anti-virus software installed on all users’ computers; on all file servers; how frequently do they update anti-virus ...
Some Tools for Computer Security Incident Response
... (nslookup), traceroute, ping, strings, netstat, top (endless…) Advance Unix command line tools gnupg , ssh, snort, airsnort, hping2, nmap, kismet, netcat(nc), tcpdump, wget, tcpreplay, aircrack Powerful tools. Tripwire, Argus, Tor, Nepenthes ...
... (nslookup), traceroute, ping, strings, netstat, top (endless…) Advance Unix command line tools gnupg , ssh, snort, airsnort, hping2, nmap, kismet, netcat(nc), tcpdump, wget, tcpreplay, aircrack Powerful tools. Tripwire, Argus, Tor, Nepenthes ...
os_ch1-2008
... Protection and Security (2) • Systems generally first distinguish among users, to determine who can do what – User identities (user IDs, security IDs) include name and associated number, one per user – User ID then associated with all files, processes of that user to determine access control – Grou ...
... Protection and Security (2) • Systems generally first distinguish among users, to determine who can do what – User identities (user IDs, security IDs) include name and associated number, one per user – User ID then associated with all files, processes of that user to determine access control – Grou ...
Operating System
... time, resources must be allocated to each of them. Critical resources: CPU time, main memory and file storage. May want to keep track of which users use how much and what kind of resources. Could be useful for billing or for usage statistics. When several separate processes execute concurrently, it ...
... time, resources must be allocated to each of them. Critical resources: CPU time, main memory and file storage. May want to keep track of which users use how much and what kind of resources. Could be useful for billing or for usage statistics. When several separate processes execute concurrently, it ...
slides.01.pdf
... with some parameters. The command should correspond with a program name (i.e. executable file). • Start a process that executes the program, i.e. loads the specified file into memory, and starts executing it. • Wait until the child process has finished. ...
... with some parameters. The command should correspond with a program name (i.e. executable file). • Start a process that executes the program, i.e. loads the specified file into memory, and starts executing it. • Wait until the child process has finished. ...
Chapter 2 Operating
... specifications. At the highest level, the design of the system will be affected by the choice of hardware and the type of system. Once an operating system is designed, it must be implemented. Traditionally, operating systems have been written in assembly language. Now, however, they are most commonl ...
... specifications. At the highest level, the design of the system will be affected by the choice of hardware and the type of system. Once an operating system is designed, it must be implemented. Traditionally, operating systems have been written in assembly language. Now, however, they are most commonl ...
- Longwood Blogs
... Assist with network, printer, computer, and peripheral configuration Remove virus, malware, and perform maintenance on various operating systems Train students on safe and secure computer usage Develop and update Longwood’s network configuration tool ...
... Assist with network, printer, computer, and peripheral configuration Remove virus, malware, and perform maintenance on various operating systems Train students on safe and secure computer usage Develop and update Longwood’s network configuration tool ...
Document - Oman College of Management & Technology
... machine is isolated from all other virtual machines. This isolation, however, permits no direct sharing of resources. A virtual-machine system is a perfect vehicle for operating-systems research and development. System development is done on the virtual machine, instead of on a physical machine an ...
... machine is isolated from all other virtual machines. This isolation, however, permits no direct sharing of resources. A virtual-machine system is a perfect vehicle for operating-systems research and development. System development is done on the virtual machine, instead of on a physical machine an ...
1. Introduction (by Andy Wang)
... computers with networks OS design goal: ease of resource sharing among machines ...
... computers with networks OS design goal: ease of resource sharing among machines ...
Operating System
... Simple Batch Systems Multiprogrammed Batch Systems Time-Sharing Systems ...
... Simple Batch Systems Multiprogrammed Batch Systems Time-Sharing Systems ...
PHP Security
... passthru( ), or the back-tick operator), this is extreemly dangerous if the program name or any of its arguments are based on user input. Instead use escapeshellarg( ) or escapeshellcmd( ) so that users can’t trick the system into executing arbitrary commands.
... passthru( ), or the back-tick operator), this is extreemly dangerous if the program name or any of its arguments are based on user input. Instead use escapeshellarg( ) or escapeshellcmd( ) so that users can’t trick the system into executing arbitrary commands.
What Is Operating System? Operating Systems, System Calls, and Buffered I/O
... close closes a file descriptor, so that it no longer refers to any file and may be reused. Any locks held on the file it was associated with, and owned by the process, are removed (regardless of the file descriptor that was used to obtain the lock) . . . . ...
... close closes a file descriptor, so that it no longer refers to any file and may be reused. Any locks held on the file it was associated with, and owned by the process, are removed (regardless of the file descriptor that was used to obtain the lock) . . . . ...
CH04-CompSec2e - MCST-CS
... enables privileged programs to access files / resources not generally accessible ...
... enables privileged programs to access files / resources not generally accessible ...
CS 381 Operating Systems
... devices and issues such as concurrency and failure. The user gets an abstraction of hardware resources, which is convenient to use and allows for efficient utilization of these resources. This course provides an opportunity to learn about operating systems through: ...
... devices and issues such as concurrency and failure. The user gets an abstraction of hardware resources, which is convenient to use and allows for efficient utilization of these resources. This course provides an opportunity to learn about operating systems through: ...
Chapter 2 Operating System Overview
... Controlled access to resources, e.g. files System access Error detection and response Accounting ...
... Controlled access to resources, e.g. files System access Error detection and response Accounting ...
History of UNIX a short version
... In 1974, Ritchie and Thompson published a paper about UNIX Many universities were interested AT&T licensed UNIX for a modest fee Releases were distributed as C source code By 1977, more than 500 sites (125 universities) were running UNIX ...
... In 1974, Ritchie and Thompson published a paper about UNIX Many universities were interested AT&T licensed UNIX for a modest fee Releases were distributed as C source code By 1977, more than 500 sites (125 universities) were running UNIX ...
Powerpoint with iClicker Questions
... command-line Windows commands Save it as C:\Documents and Settings\ username\cmd.bat Start, Run, CMD will execute this file instead of C:\Windows\System32\Cmd.exe ...
... command-line Windows commands Save it as C:\Documents and Settings\ username\cmd.bat Start, Run, CMD will execute this file instead of C:\Windows\System32\Cmd.exe ...
Basics of Operating Systems
... on successful completion of the course student is supposed to: define the basic structure of the operating system, describe the basic functions and features of operating systems, identify one-purpose and multi-tasking systems, as well as single-threaded and multithreaded, will be able to define conc ...
... on successful completion of the course student is supposed to: define the basic structure of the operating system, describe the basic functions and features of operating systems, identify one-purpose and multi-tasking systems, as well as single-threaded and multithreaded, will be able to define conc ...
CCN3133 Computer System Principles
... theorems, principles and mathematics techniques of computer systems and operating systems. In addition, examples of modern computer systems and operating systems will be discussed in lectures. Tutorials will introduce the commonly used software in performing file system management, process control, ...
... theorems, principles and mathematics techniques of computer systems and operating systems. In addition, examples of modern computer systems and operating systems will be discussed in lectures. Tutorials will introduce the commonly used software in performing file system management, process control, ...
Homework: OS Organization
... Submit: In lab 4 you completed building the core of an exokernel-based operating system. In class you studied xv6, a monolithic operating systems. Both are intend to support the UNIX API, but their internal organizations are different. A good example is the virtual memory implementation: JOS impleme ...
... Submit: In lab 4 you completed building the core of an exokernel-based operating system. In class you studied xv6, a monolithic operating systems. Both are intend to support the UNIX API, but their internal organizations are different. A good example is the virtual memory implementation: JOS impleme ...
UNIX Operating System
... The /dev/initrd file is a read-only block device. The /dev/initrd is a RAM disk device that is loaded by the boot loader into memory before the kernel is started. The kernel utilizes this block device for a two phased system boot-up. During the first phase, the kernel starts up and mounts an initial ...
... The /dev/initrd file is a read-only block device. The /dev/initrd is a RAM disk device that is loaded by the boot loader into memory before the kernel is started. The kernel utilizes this block device for a two phased system boot-up. During the first phase, the kernel starts up and mounts an initial ...
Introduction - Stanford Secure Computer Systems Group
... Different system contexts • A system can typically be in one of several contexts • User-level – running an application • Kernel process context - Running kernel code on behalf of a particular process - E.g., performing system call - Also exception (mem. fault, numeric exception, etc.) - Or executin ...
... Different system contexts • A system can typically be in one of several contexts • User-level – running an application • Kernel process context - Running kernel code on behalf of a particular process - E.g., performing system call - Also exception (mem. fault, numeric exception, etc.) - Or executin ...
Windows File System
... • File allocation is done on a block basis. • Allocation is dynamic – Blocks may not be contiguous ...
... • File allocation is done on a block basis. • Allocation is dynamic – Blocks may not be contiguous ...
Module 3: Operating
... program into memory and to run it. I/O operations – since user programs cannot execute I/O operations directly, the operating system must provide some means to perform I/O. File-system manipulation – program capability to read, write, create, and delete files. Communications – exchange of informatio ...
... program into memory and to run it. I/O operations – since user programs cannot execute I/O operations directly, the operating system must provide some means to perform I/O. File-system manipulation – program capability to read, write, create, and delete files. Communications – exchange of informatio ...