Operating Systems Homework Assignment 2
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Process and Memory Management Commands
Process and Memory Management Commands This chapter describes the Cisco IOS XR software commands used to manage processes and memory. For more information about using the process and memory management commands to perform troubleshooting tasks, see Cisco ASR 9000 Series Aggregation Services Router Getting Started Guide. • clear context, on page 2 • dumpcore, on page 3 • exception coresize, on page 6 • exception filepath, on page 8 • exception pakmem, on page 12 • exception sparse, on page 14 • exception sprsize, on page 16 • follow, on page 18 • monitor threads, on page 25 • process, on page 29 • process core, on page 32 • process mandatory, on page 34 • show context, on page 36 • show dll, on page 39 • show exception, on page 42 • show memory, on page 44 • show memory compare, on page 47 • show memory heap, on page 50 • show processes, on page 54 Process and Memory Management Commands 1 Process and Memory Management Commands clear context clear context To clear core dump context information, use the clear context command in the appropriate mode. clear context location {node-id | all} Syntax Description location{node-id | all} (Optional) Clears core dump context information for a specified node. The node-id argument is expressed in the rack/slot/module notation. Use the all keyword to indicate all nodes. Command Default No default behavior or values Command Modes Administration EXEC EXEC mode Command History Release Modification Release 3.7.2 This command was introduced. Release 3.9.0 No modification. Usage Guidelines To use this command, you must be in a user group associated with a task group that includes appropriate task IDs. -
Command Line Interface Specification Windows
Command Line Interface Specification Windows Online Backup Client version 4.3.x 1. Introduction The CloudBackup Command Line Interface (CLI for short) makes it possible to access the CloudBackup Client software from the command line. The following actions are implemented: backup, delete, dir en restore. These actions are described in more detail in the following paragraphs. For all actions applies that a successful action is indicated by means of exit code 0. In all other cases a status code of 1 will be used. 2. Configuration The command line client needs a configuration file. This configuration file may have the same layout as the configuration file for the full CloudBackup client. This configuration file is expected to reside in one of the following folders: CLI installation location or the settings folder in the CLI installation location. The name of the configuration file must be: Settings.xml. Example: if the CLI is installed in C:\Windows\MyBackup\, the configuration file may be in one of the two following locations: C:\Windows\MyBackup\Settings.xml C:\Windows\MyBackup\Settings\Settings.xml If both are present, the first form has precedence. Also the customer needs to edit the CloudBackup.Console.exe.config file which is located in the program file directory and edit the following line: 1 <add key="SettingsFolder" value="%settingsfilelocation%" /> After making these changes the customer can use the CLI instruction to make backups and restore data. 2.1 Configuration Error Handling If an error is found in the configuration file, the command line client will issue an error message describing which value or setting or option is causing the error and terminate with an exit value of 1. -
Process Management
Princeton University Computer Science 217: Introduction to Programming Systems Process Management 1 Goals of this Lecture Help you learn about: • Creating new processes • Waiting for processes to terminate • Executing new programs • Shell structure Why? • Creating new processes and executing new programs are fundamental tasks of many utilities and end-user applications • Assignment 7… 2 System-Level Functions As noted in the Exceptions and Processes lecture… Linux system-level functions for process management Function Description exit() Terminate the process fork() Create a child process wait() Wait for child process termination execvp() Execute a program in current process getpid() Return the process id of the current process 3 Agenda Creating new processes Waiting for processes to terminate Executing new programs Shell structure 4 Why Create New Processes? Why create a new process? • Scenario 1: Program wants to run an additional instance of itself • E.g., web server receives request; creates additional instance of itself to handle the request; original instance continues listening for requests • Scenario 2: Program wants to run a different program • E.g., shell receives a command; creates an additional instance of itself; additional instance overwrites itself with requested program to handle command; original instance continues listening for commands How to create a new process? • A “parent” process forks a “child” process • (Optionally) child process overwrites itself with a new program, after performing appropriate setup 5 fork System-Level -
Attacker Antics Illustrations of Ingenuity
ATTACKER ANTICS ILLUSTRATIONS OF INGENUITY Bart Inglot and Vincent Wong FIRST CONFERENCE 2018 2 Bart Inglot ◆ Principal Consultant at Mandiant ◆ Incident Responder ◆ Rock Climber ◆ Globetrotter ▶ From Poland but live in Singapore ▶ Spent 1 year in Brazil and 8 years in the UK ▶ Learning French… poor effort! ◆ Twitter: @bartinglot ©2018 FireEye | Private & Confidential 3 Vincent Wong ◆ Principal Consultant at Mandiant ◆ Incident Responder ◆ Baby Sitter ◆ 3 years in Singapore ◆ Grew up in Australia ©2018 FireEye | Private & Confidential 4 Disclosure Statement “ Case studies and examples are drawn from our experiences and activities working for a variety of customers, and do not represent our work for any one customer or set of customers. In many cases, facts have been changed to obscure the identity of our customers and individuals associated with our customers. ” ©2018 FireEye | Private & Confidential 5 Today’s Tales 1. AV Server Gone Bad 2. Stealing Secrets From An Air-Gapped Network 3. A Backdoor That Uses DNS for C2 4. Hidden Comment That Can Haunt You 5. A Little Known Persistence Technique 6. Securing Corporate Email is Tricky 7. Hiding in Plain Sight 8. Rewriting Import Table 9. Dastardly Diabolical Evil (aka DDE) ©2018 FireEye | Private & Confidential 6 AV SERVER GONE BAD Cobalt Strike, PowerShell & McAfee ePO (1/9) 7 AV Server Gone Bad – Background ◆ Attackers used Cobalt Strike (along with other malware) ◆ Easily recognisable IOCs when recorded by Windows Event Logs ▶ Random service name – also seen with Metasploit ▶ Base64-encoded script, “%COMSPEC%” and “powershell.exe” ▶ Decoding the script yields additional PowerShell script with a base64-encoded GZIP stream that in turn contained a base64-encoded Cobalt Strike “Beacon” payload. -
Powershell Integration with Vmware View 5.0
PowerShell Integration with VMware® View™ 5.0 TECHNICAL WHITE PAPER PowerShell Integration with VMware View 5.0 Table of Contents Introduction . 3 VMware View. 3 Windows PowerShell . 3 Architecture . 4 Cmdlet dll. 4 Communication with Broker . 4 VMware View PowerCLI Integration . 5 VMware View PowerCLI Prerequisites . 5 Using VMware View PowerCLI . 5 VMware View PowerCLI cmdlets . 6 vSphere PowerCLI Integration . 7 Examples of VMware View PowerCLI and VMware vSphere PowerCLI Integration . 7 Passing VMs from Get-VM to VMware View PowerCLI cmdlets . 7 Registering a vCenter Server . .. 7 Using Other VMware vSphere Objects . 7 Advanced Usage . 7 Integrating VMware View PowerCLI into Your Own Scripts . 8 Scheduling PowerShell Scripts . 8 Workflow with VMware View PowerCLI and VMware vSphere PowerCLI . 9 Sample Scripts . 10 Add or Remove Datastores in Automatic Pools . 10 Add or Remove Virtual Machines . 11 Inventory Path Manipulation . 15 Poll Pool Usage . 16 Basic Troubleshooting . 18 About the Authors . 18 TECHNICAL WHITE PAPER / 2 PowerShell Integration with VMware View 5.0 Introduction VMware View VMware® View™ is a best-in-class enterprise desktop virtualization platform. VMware View separates the personal desktop environment from the physical system by moving desktops to a datacenter, where users can access them using a client-server computing model. VMware View delivers a rich set of features required for any enterprise deployment by providing a robust platform for hosting virtual desktops from VMware vSphere™. Windows PowerShell Windows PowerShell is Microsoft’s command line shell and scripting language. PowerShell is built on the Microsoft .NET Framework and helps in system administration. By providing full access to COM (Component Object Model) and WMI (Windows Management Instrumentation), PowerShell enables administrators to perform administrative tasks on both local and remote Windows systems. -
Linux-PATH.Pdf
http://www.linfo.org/path_env_var.html PATH Definition PATH is an environmental variable in Linux and other Unix-like operating systems that tells the shell which directories to search for executable files (i.e., ready-to-run programs ) in response to commands issued by a user. It increases both the convenience and the safety of such operating systems and is widely considered to be the single most important environmental variable. Environmental variables are a class of variables (i.e., items whose values can be changed) that tell the shell how to behave as the user works at the command line (i.e., in a text-only mode) or with shell scripts (i.e., short programs written in a shell programming language). A shell is a program that provides the traditional, text-only user interface for Unix-like operating systems; its primary function is to read commands that are typed in at the command line and then execute (i.e., run) them. PATH (which is written with all upper case letters) should not be confused with the term path (lower case letters). The latter is a file's or directory's address on a filesystem (i.e., the hierarchy of directories and files that is used to organize information stored on a computer ). A relative path is an address relative to the current directory (i.e., the directory in which a user is currently working). An absolute path (also called a full path ) is an address relative to the root directory (i.e., the directory at the very top of the filesystem and which contains all other directories and files). -
Practical Session 1, System Calls a Few Administrative Notes…
Operating Systems, 142 Tas: Vadim Levit , Dan Brownstein, Ehud Barnea, Matan Drory and Yerry Sofer Practical Session 1, System Calls A few administrative notes… • Course homepage: http://www.cs.bgu.ac.il/~os142/ • Contact staff through the dedicated email: [email protected] (format the subject of your email according to the instructions listed in the course homepage) • Assignments: Extending xv6 (a pedagogical OS) Submission in pairs. Frontal checking: 1. Assume the grader may ask anything. 2. Must register to exactly one checking session. System Calls • A System Call is an interface between a user application and a service provided by the operating system (or kernel). • These can be roughly grouped into five major categories: 1. Process control (e.g. create/terminate process) 2. File Management (e.g. read, write) 3. Device Management (e.g. logically attach a device) 4. Information Maintenance (e.g. set time or date) 5. Communications (e.g. send messages) System Calls - motivation • A process is not supposed to access the kernel. It can’t access the kernel memory or functions. • This is strictly enforced (‘protected mode’) for good reasons: • Can jeopardize other processes running. • Cause physical damage to devices. • Alter system behavior. • The system call mechanism provides a safe mechanism to request specific kernel operations. System Calls - interface • Calls are usually made with C/C++ library functions: User Application C - Library Kernel System Call getpid() Load arguments, eax _NR_getpid, kernel mode (int 80) Call sys_getpid() Sys_Call_table[eax] syscall_exit return resume_userspace return User-Space Kernel-Space Remark: Invoking int 0x80 is common although newer techniques for “faster” control transfer are provided by both AMD’s and Intel’s architecture. -
HP Decset for Openvms Guide to the Module Management System
HP DECset for OpenVMS Guide to the Module Management System Order Number: AA–P119J–TE July 2005 This guide describes the Module Management System (MMS) and explains how to get started using its basic features. Revision/Update Information: This is a revised manual. Operating System Version: OpenVMS I64 Version 8.2 OpenVMS Alpha Version 7.3–2 or 8.2 OpenVMS VAX Version 7.3 Windowing System Version: DECwindows Motif for OpenVMS I64 Version 1.5 DECwindows Motif for OpenVMS Alpha Version 1.3–1 or 1.5 DECwindows Motif for OpenVMS VAX Version 1.2–6 Software Version: HP DECset Version 12.7 for OpenVMS Hewlett-Packard Company Palo Alto, California © Copyright 2005 Hewlett-Packard Development Company, L.P. Confidential computer software. Valid license from HP required for possession, use or copying. Consistent with FAR 12.211 and 12.212, Commercial Computer Software, Computer Software Documentation, and Technical Data for Commercial Items are licensed to the U.S. Government under vendor’s standard commercial license. The information contained herein is subject to change without notice. The only warranties for HP products and services are set forth in the express warranty statements accompanying such products and services. Nothing herein should be construed as constituting an additional warranty. HP shall not be liable for technical or editorial errors or omissions contained herein. Intel and Itanium are trademarks or registered trademarks of Intel Corporation or its subsidiaries in the United States and other countries. Java is a US trademark of Sun Microsystems, Inc. Microsoft, Windows, and Windows NT are U.S. registered trademarks of Microsoft Corporation. -
How to Write a File Copy Program in Standard C? #Include <Stdio.H>
Files How to write a file copy program in standard C? #include <stdio.h> FILE *fopen(const char *path, const char *mode); size_t fread(void *ptr, size_t size, size_t nmemb, FILE *stream); size_t fwrite(const void *ptr, size_t size, size_t nmemb, FILE *stream); int fclose(FILE *fp); We can also use character-based functions such as: #include <stdio.h> int fgetc(FILE *stream); int fputc(int c, FILE *stream); With either approach, we can write a C program that will work on any operating system as it is in standard C. What is the difference between the two approaches? /* lab/stdc-mycp.c */ /* appropriate header files */ #define BUF_SIZE 65536 int main(int argc, char *argv[]) { FILE *src, *dst; size_t in, out; char buf[BUF_SIZE]; int bufsize; if (argc != 4) { fprintf(stderr, "Usage: %s <buffer size> <src> <dest>\n", argv[0]); exit(1); } bufsize = atoi(argv[1]); if (bufsize > BUF_SIZE) { fprintf(stderr,"Error: %s: max. buffer size is %d\n",argv[0], BUF_SIZE); exit(1); } src = fopen(argv[2], "r"); if (NULL == src) exit(2); dst = fopen(argv[3], "w"); if (dst < 0) exit(3); while (1) { in = fread(buf, 1, bufsize, src); if (0 == in) break; out = fwrite(buf, 1, in, dst); if (0 == out) break; } fclose(src); fclose(dst); exit(0); } POSIX/Unix File Interface The system call interface for files in POSIX systems like Linux and MacOSX. A file is a named, ordered stream of bytes. I open(..) Open a file for reading or writing. Also allows a file to be locked providing exclusive access. I close(..) I read(..) The read operation is normally blocking. -
Linux-Kernel
linux-kernel #linux- kernel Table of Contents About 1 Chapter 1: Getting started with linux-kernel 2 Remarks 2 Versions 2 Examples 2 Installation or Setup 2 Download extract and enter to the kernel directory 2 Build the dependencies, compile the kernel and modules. 3 Chapter 2: Creation and usage of Kernel Threads 4 Introduction 4 Examples 4 Creation of kernel threads 4 Chapter 3: Event Tracing 6 Examples 6 Tracing I2C Events 6 Chapter 4: Fork System call 7 Examples 7 fork() system call 7 Chapter 5: How to find the right person for help. 9 Introduction 9 Examples 9 Find the "likely" maintainers for the FTDI USB serial converter 9 Chapter 6: Linux Hello World Device driver 10 Examples 10 An empty kernel module 10 Building and running the module 10 Chapter 7: Linux: Named Pipes(FIFO) 12 Examples 12 What is Named Pipe (FIFO) 12 Credits 13 About You can share this PDF with anyone you feel could benefit from it, downloaded the latest version from: linux-kernel It is an unofficial and free linux-kernel ebook created for educational purposes. All the content is extracted from Stack Overflow Documentation, which is written by many hardworking individuals at Stack Overflow. It is neither affiliated with Stack Overflow nor official linux-kernel. The content is released under Creative Commons BY-SA, and the list of contributors to each chapter are provided in the credits section at the end of this book. Images may be copyright of their respective owners unless otherwise specified. All trademarks and registered trademarks are the property of their respective company owners. -
Operating System Lab Manual
OPERATING SYSTEM LAB MANUAL BASICS OF UNIX COMMANDS Ex.No:1.a INTRODUCTION TO UNIX AIM: To study about the basics of UNIX UNIX: It is a multi-user operating system. Developed at AT & T Bell Industries, USA in 1969. Ken Thomson along with Dennis Ritchie developed it from MULTICS (Multiplexed Information and Computing Service) OS. By1980, UNIX had been completely rewritten using C langua ge. LINUX: It is similar to UNIX, which is created by Linus Torualds. All UNIX commands works in Linux. Linux is a open source software. The main feature of Linux is coexisting with other OS such as windows and UNIX. STRUCTURE OF A LINUXSYSTEM: It consists of three parts. a)UNIX kernel b) Shells c) Tools and Applications UNIX KERNEL: Kernel is the core of the UNIX OS. It controls all tasks, schedule all Processes and carries out all the functions of OS. Decides when one programs tops and another starts. SHELL: Shell is the command interpreter in the UNIX OS. It accepts command from the user and analyses and interprets them 1 | P a g e BASICS OF UNIX COMMANDS Ex.No:1.b BASIC UNIX COMMANDS AIM: To study of Basic UNIX Commands and various UNIX editors such as vi, ed, ex and EMACS. CONTENT: Note: Syn->Syntax a) date –used to check the date and time Syn:$date Format Purpose Example Result +%m To display only month $date+%m 06 +%h To display month name $date+%h June +%d To display day of month $date+%d O1 +%y To display last two digits of years $date+%y 09 +%H To display hours $date+%H 10 +%M To display minutes $date+%M 45 +%S To display seconds $date+%S 55 b) cal –used to display the calendar Syn:$cal 2 2009 c)echo –used to print the message on the screen. -
The Big Picture So Far Today: Process Management
The Big Picture So Far From the Architecture to the OS to the User: Architectural resources, OS management, and User Abstractions. Hardware abstraction Example OS Services User abstraction Processor Process management, Scheduling, Traps, Process protection, accounting, synchronization Memory Management, Protection, virtual memory Address spaces I/O devices Concurrency with CPU, Interrupt Terminal, mouse, printer, handling system calls File System File management, Persistence Files Distributed systems Networking, security, distributed file Remote procedure calls, system network file system System calls Four architectures for designing OS kernels Computer Science CS377: Operating Systems Lecture 4, page 1 Today: Process Management • A process as the unit of execution. • How are processes represented in the OS? • What are possible execution states and how does the system move from one state to another? • How are processes created in the system? • How do processes communicate? Is this efficient? Computer Science CS377: Operating Systems Lecture 4, page 2 What's in a Process? • Process: dynamic execution context of an executing program • Several processes may run the same program, but each is a distinct process with its own state (e.g., MS Word). • A process executes sequentially, one instruction at a time • Process state consists of at least: ! the code for the running program, ! the static data for the running program, ! space for dynamic data (the heap), the heap pointer (HP), ! the Program Counter (PC), indicating the next instruction, ! an execution stack with the program's call chain (the stack), the stack pointer (SP) ! values of CPU registers ! a set of OS resources in use (e.g., open files) ! process execution state (ready, running, etc.).