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GNU/Linux AI & Alife HOWTO
GNU/Linux AI & Alife HOWTO GNU/Linux AI & Alife HOWTO Table of Contents GNU/Linux AI & Alife HOWTO......................................................................................................................1 by John Eikenberry..................................................................................................................................1 1. Introduction..........................................................................................................................................1 2. Symbolic Systems (GOFAI)................................................................................................................1 3. Connectionism.....................................................................................................................................1 4. Evolutionary Computing......................................................................................................................1 5. Alife & Complex Systems...................................................................................................................1 6. Agents & Robotics...............................................................................................................................1 7. Statistical & Machine Learning...........................................................................................................2 8. Missing & Dead...................................................................................................................................2 1. Introduction.........................................................................................................................................2 -
CST8207 – Linux O/S I
Mounting a Filesystem Directory Structure Fstab Mount command CST8207 - Algonquin College 2 Chapter 12: page 467 - 496 CST8207 - Algonquin College 3 The mount utility connects filesystems to the Linux directory hierarchy. The mount point is a directory in the local filesystem where you can access mounted filesystem. This directory must exist before you can mount a filesystem. All filesystems visible on the system exist as a mounted filesystem someplace below the root (/) directory CST8207 - Algonquin College 4 can be mounted manually ◦ can be listed in /etc/fstab, but not necessary ◦ all mounting information supplied manually at command line by user or administrator can be mounted automatically on startup ◦ must be listed /etc/fstab, with all appropriate information and options required Every filesystem, drive, storage device is listed as a mounted filesystem associated to a directory someplace under the root (/) directory CST8207 - Algonquin College 5 CST8207 - Algonquin College 6 Benefits Scalable ◦ As new drives are added and new partitions are created, further filesystems can be mounted at various mount points as required. ◦ This means a Linux system does not need to worry about running out of disk space. Transparent ◦ No application would stop working if transferred to a different partition, because access to data is done via the mount point. ◦ Also transparent to user CST8207 - Algonquin College 7 All known filesystems volumes are typically listed in the /etc/fstab (static information about filesystem) file to help automate the mounting process If it is not listed in the /etc/fstab file, then all appropriate information about the filesystem needs to be listed manually at the command line. -
A Brief History of UNIX File Systems
A Brief History of UNIX File Systems Val Henson IBM, Inc. [email protected] Summary • Review of UNIX file system concepts • File system formats, 1974-2004 • File system comparisons and recommendations • Fun trivia • Questions and answers (corrections ONLY during talk) 1 VFS/vnode architecture • VFS: Virtual File System: common object-oriented interface to fs's • vnode: virtual node: abstract file object, includes vnode ops • All operations to fs's and files done through VFS/vnode in- terface • S.R. Kleiman, \Vnodes: An Architecture for Multiple File System Types in Sun UNIX," Summer USENIX 1986 2 Some Definitions superblock: fs summary, pointers to other information inode: on-disk structure containing information about a file indirect block: block containing pointers to other blocks metadata: everything that is not user data, including directory entries 3 Disk characteristics • Track - contiguous region, can be read at maximum speed • Seek time - time to move the head between different tracks • Rotational delay - time for part of track to move under head • Fixed per I/O overhead means bigger I/Os are better 4 In the beginning: System V FS (S5FS) (c. 1974) • First UNIX file system, referred to as \FS" • Disk layout: superblock, inodes, followed by everything else • 512-1024 byte block size, no fragments • Super simple - and super slow! 2-5% of raw disk bandwidth 5 Berkeley Fast File System (FFS or UFS) (c. 1984) • Metadata spread throughout the disk in \cylinder groups" • Block size 4KB minimum, frag size 1KB (to avoid 45% wasted space) • Physical -
Beginning Portable Shell Scripting from Novice to Professional
Beginning Portable Shell Scripting From Novice to Professional Peter Seebach 10436fmfinal 1 10/23/08 10:40:24 PM Beginning Portable Shell Scripting: From Novice to Professional Copyright © 2008 by Peter Seebach All rights reserved. No part of this work may be reproduced or transmitted in any form or by any means, electronic or mechanical, including photocopying, recording, or by any information storage or retrieval system, without the prior written permission of the copyright owner and the publisher. ISBN-13 (pbk): 978-1-4302-1043-6 ISBN-10 (pbk): 1-4302-1043-5 ISBN-13 (electronic): 978-1-4302-1044-3 ISBN-10 (electronic): 1-4302-1044-3 Printed and bound in the United States of America 9 8 7 6 5 4 3 2 1 Trademarked names may appear in this book. Rather than use a trademark symbol with every occurrence of a trademarked name, we use the names only in an editorial fashion and to the benefit of the trademark owner, with no intention of infringement of the trademark. Lead Editor: Frank Pohlmann Technical Reviewer: Gary V. Vaughan Editorial Board: Clay Andres, Steve Anglin, Ewan Buckingham, Tony Campbell, Gary Cornell, Jonathan Gennick, Michelle Lowman, Matthew Moodie, Jeffrey Pepper, Frank Pohlmann, Ben Renow-Clarke, Dominic Shakeshaft, Matt Wade, Tom Welsh Project Manager: Richard Dal Porto Copy Editor: Kim Benbow Associate Production Director: Kari Brooks-Copony Production Editor: Katie Stence Compositor: Linda Weidemann, Wolf Creek Press Proofreader: Dan Shaw Indexer: Broccoli Information Management Cover Designer: Kurt Krames Manufacturing Director: Tom Debolski Distributed to the book trade worldwide by Springer-Verlag New York, Inc., 233 Spring Street, 6th Floor, New York, NY 10013. -
Bringing GNU Emacs to Native Code
Bringing GNU Emacs to Native Code Andrea Corallo Luca Nassi Nicola Manca [email protected] [email protected] [email protected] CNR-SPIN Genoa, Italy ABSTRACT such a long-standing project. Although this makes it didactic, some Emacs Lisp (Elisp) is the Lisp dialect used by the Emacs text editor limitations prevent the current implementation of Emacs Lisp to family. GNU Emacs can currently execute Elisp code either inter- be appealing for broader use. In this context, performance issues preted or byte-interpreted after it has been compiled to byte-code. represent the main bottleneck, which can be broken down in three In this work we discuss the implementation of an optimizing com- main sub-problems: piler approach for Elisp targeting native code. The native compiler • lack of true multi-threading support, employs the byte-compiler’s internal representation as input and • garbage collection speed, exploits libgccjit to achieve code generation using the GNU Com- • code execution speed. piler Collection (GCC) infrastructure. Generated executables are From now on we will focus on the last of these issues, which con- stored as binary files and can be loaded and unloaded dynamically. stitutes the topic of this work. Most of the functionality of the compiler is written in Elisp itself, The current implementation traditionally approaches the prob- including several optimization passes, paired with a C back-end lem of code execution speed in two ways: to interface with the GNU Emacs core and libgccjit. Though still a work in progress, our implementation is able to bootstrap a func- • Implementing a large number of performance-sensitive prim- tional Emacs and compile all lexically scoped Elisp files, including itive functions (also known as subr) in C. -
Unix/Linux Command Reference
Unix/Linux Command Reference .com File Commands System Info ls – directory listing date – show the current date and time ls -al – formatted listing with hidden files cal – show this month's calendar cd dir - change directory to dir uptime – show current uptime cd – change to home w – display who is online pwd – show current directory whoami – who you are logged in as mkdir dir – create a directory dir finger user – display information about user rm file – delete file uname -a – show kernel information rm -r dir – delete directory dir cat /proc/cpuinfo – cpu information rm -f file – force remove file cat /proc/meminfo – memory information rm -rf dir – force remove directory dir * man command – show the manual for command cp file1 file2 – copy file1 to file2 df – show disk usage cp -r dir1 dir2 – copy dir1 to dir2; create dir2 if it du – show directory space usage doesn't exist free – show memory and swap usage mv file1 file2 – rename or move file1 to file2 whereis app – show possible locations of app if file2 is an existing directory, moves file1 into which app – show which app will be run by default directory file2 ln -s file link – create symbolic link link to file Compression touch file – create or update file tar cf file.tar files – create a tar named cat > file – places standard input into file file.tar containing files more file – output the contents of file tar xf file.tar – extract the files from file.tar head file – output the first 10 lines of file tar czf file.tar.gz files – create a tar with tail file – output the last 10 lines -
File System, Files, and *Tab /Etc/Fstab
File system, files, and *tab File system files directories volumes, file systems mounting points local versus networked file systems 1 /etc/fstab Specifies what is to be mounted where and how fs_spec: describes block special device for remote filesystem to be mounted fs_file: describes the mount point fs_vfstype: describes the type of file system fs_mntops: describes the mount options associated with the filesystem 2 /etc/fstab cont. fs_freq: used by the dump command fs_passno: used by fsck to determine the order in which checks are done at boot time. Root file systems should be specified as 1, others should be 2. Value 0 means that file system does not need to be checked 3 /etc/fstab 4 from blocks to mounting points metadata inodes directories superblocks 5 mounting file systems mounting e.g., mount -a unmounting manually or during shutdown umount 6 /etc/mtab see what is mounted 7 Network File System Access file system (FS) over a network looks like a local file system to user e.g. mount user FS rather than duplicating it (which would be a disaster) Developed by Sun Microsystems (mid 80s) history for NFS: NFS, NFSv2, NFSv3, NFSv4 RFC 3530 (from 2003) take a look to see what these RFCs are like!) 8 Network File System How does this actually work? server needs to export the system client needs to mount the system server: /etc/exports file client: /etc/fstab file 9 Network File System Security concerns UID GID What problems could arise? 10 Network File System example from our raid system (what is a RAID again?) Example of exports file from -
The Linux Command Line
The Linux Command Line Fifth Internet Edition William Shotts A LinuxCommand.org Book Copyright ©2008-2019, William E. Shotts, Jr. This work is licensed under the Creative Commons Attribution-Noncommercial-No De- rivative Works 3.0 United States License. To view a copy of this license, visit the link above or send a letter to Creative Commons, PO Box 1866, Mountain View, CA 94042. A version of this book is also available in printed form, published by No Starch Press. Copies may be purchased wherever fine books are sold. No Starch Press also offers elec- tronic formats for popular e-readers. They can be reached at: https://www.nostarch.com. Linux® is the registered trademark of Linus Torvalds. All other trademarks belong to their respective owners. This book is part of the LinuxCommand.org project, a site for Linux education and advo- cacy devoted to helping users of legacy operating systems migrate into the future. You may contact the LinuxCommand.org project at http://linuxcommand.org. Release History Version Date Description 19.01A January 28, 2019 Fifth Internet Edition (Corrected TOC) 19.01 January 17, 2019 Fifth Internet Edition. 17.10 October 19, 2017 Fourth Internet Edition. 16.07 July 28, 2016 Third Internet Edition. 13.07 July 6, 2013 Second Internet Edition. 09.12 December 14, 2009 First Internet Edition. Table of Contents Introduction....................................................................................................xvi Why Use the Command Line?......................................................................................xvi -
Filesystem Hierarchy Standard
Filesystem Hierarchy Standard LSB Workgroup, The Linux Foundation Filesystem Hierarchy Standard LSB Workgroup, The Linux Foundation Version 3.0 Publication date March 19, 2015 Copyright © 2015 The Linux Foundation Copyright © 1994-2004 Daniel Quinlan Copyright © 2001-2004 Paul 'Rusty' Russell Copyright © 2003-2004 Christopher Yeoh Abstract This standard consists of a set of requirements and guidelines for file and directory placement under UNIX-like operating systems. The guidelines are intended to support interoperability of applications, system administration tools, development tools, and scripts as well as greater uniformity of documentation for these systems. All trademarks and copyrights are owned by their owners, unless specifically noted otherwise. Use of a term in this document should not be regarded as affecting the validity of any trademark or service mark. Permission is granted to make and distribute verbatim copies of this standard provided the copyright and this permission notice are preserved on all copies. Permission is granted to copy and distribute modified versions of this standard under the conditions for verbatim copying, provided also that the title page is labeled as modified including a reference to the original standard, provided that information on retrieving the original standard is included, and provided that the entire resulting derived work is distributed under the terms of a permission notice identical to this one. Permission is granted to copy and distribute translations of this standard into another language, under the above conditions for modified versions, except that this permission notice may be stated in a translation approved by the copyright holder. Dedication This release is dedicated to the memory of Christopher Yeoh, a long-time friend and colleague, and one of the original editors of the FHS. -
Powerview Command Reference
PowerView Command Reference TRACE32 Online Help TRACE32 Directory TRACE32 Index TRACE32 Documents ...................................................................................................................... PowerView User Interface ............................................................................................................ PowerView Command Reference .............................................................................................1 History ...................................................................................................................................... 12 ABORT ...................................................................................................................................... 13 ABORT Abort driver program 13 AREA ........................................................................................................................................ 14 AREA Message windows 14 AREA.CLEAR Clear area 15 AREA.CLOSE Close output file 15 AREA.Create Create or modify message area 16 AREA.Delete Delete message area 17 AREA.List Display a detailed list off all message areas 18 AREA.OPEN Open output file 20 AREA.PIPE Redirect area to stdout 21 AREA.RESet Reset areas 21 AREA.SAVE Save AREA window contents to file 21 AREA.Select Select area 22 AREA.STDERR Redirect area to stderr 23 AREA.STDOUT Redirect area to stdout 23 AREA.view Display message area in AREA window 24 AutoSTOre .............................................................................................................................. -
Evaluating UNIX Security Previous Screen Allen B
84-01-15.1 Evaluating UNIX Security Previous screen Allen B. Lum Payoff The UNIX operating system's basic security features include password protection, access permission, user profiles, shell scripts, and file ownership. Because new and enhanced UNIX security features are continually being added to these features in response to the demands of an increasingly competitive user community, information security professionals must begin with an understanding of the basic UNIX security environment. This article covers the fundamental security features that can be found in most of the currently available versions of the UNIX operating system. Several checklists are included at the end of the article to assist administrators in ensuring the security of UNIX systems. Problems Addressed The UNIX operating system was originally developed for use by programmers within an open systems environment. The adoption of UNIX as a common operating system across several different platforms has increased the need for security beyond its original purpose. As a result, many UNIX installations have less than optimal security. In addition, there are several versions of UNIX on the market today with differing security features. This article discusses basic access controls (e.g., passwords) and directory and file permissions within the UNIX system. The concepts discussed are applicable to all versions of UNIX unless specifically noted otherwise. UNIX History As the majority of UNIX users know, UNIX was developed at AT Bell Laboratories in the late 1960s by Thompson and Ritchie; the name UNIXis a contraction of uni and multics. The original UNIX system software was written in the assembler language to run on the digital PDP-7 computer. -
GNU M4, Version 1.4.7 a Powerful Macro Processor Edition 1.4.7, 23 September 2006
GNU M4, version 1.4.7 A powerful macro processor Edition 1.4.7, 23 September 2006 by Ren´eSeindal This manual is for GNU M4 (version 1.4.7, 23 September 2006), a package containing an implementation of the m4 macro language. Copyright c 1989, 1990, 1991, 1992, 1993, 1994, 2004, 2005, 2006 Free Software Foundation, Inc. Permission is granted to copy, distribute and/or modify this document under the terms of the GNU Free Documentation License, Version 1.2 or any later version published by the Free Software Foundation; with no Invariant Sections, no Front-Cover Texts, and no Back-Cover Texts. A copy of the license is included in the section entitled “GNU Free Documentation License.” i Table of Contents 1 Introduction and preliminaries ................ 3 1.1 Introduction to m4 ............................................. 3 1.2 Historical references ............................................ 3 1.3 Invoking m4 .................................................... 4 1.4 Problems and bugs ............................................. 8 1.5 Using this manual .............................................. 8 2 Lexical and syntactic conventions ............ 11 2.1 Macro names ................................................. 11 2.2 Quoting input to m4........................................... 11 2.3 Comments in m4 input ........................................ 11 2.4 Other kinds of input tokens ................................... 12 2.5 How m4 copies input to output ................................ 12 3 How to invoke macros........................