CS 449 – Executables and Linking
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Use of Seek When Writing Or Reading Binary Files
Title stata.com file — Read and write text and binary files Description Syntax Options Remarks and examples Stored results Reference Also see Description file is a programmer’s command and should not be confused with import delimited (see [D] import delimited), infile (see[ D] infile (free format) or[ D] infile (fixed format)), and infix (see[ D] infix (fixed format)), which are the usual ways that data are brought into Stata. file allows programmers to read and write both text and binary files, so file could be used to write a program to input data in some complicated situation, but that would be an arduous undertaking. Files are referred to by a file handle. When you open a file, you specify the file handle that you want to use; for example, in . file open myfile using example.txt, write myfile is the file handle for the file named example.txt. From that point on, you refer to the file by its handle. Thus . file write myfile "this is a test" _n would write the line “this is a test” (without the quotes) followed by a new line into the file, and . file close myfile would then close the file. You may have multiple files open at the same time, and you may access them in any order. 1 2 file — Read and write text and binary files Syntax Open file file open handle using filename , read j write j read write text j binary replace j append all Read file file read handle specs Write to file file write handle specs Change current location in file file seek handle query j tof j eof j # Set byte order of binary file file set handle byteorder hilo j lohi j 1 j 2 Close -
Also Includes Slides and Contents From
The Compilation Toolchain Cross-Compilation for Embedded Systems Prof. Andrea Marongiu ([email protected]) Toolchain The toolchain is a set of development tools used in association with source code or binaries generated from the source code • Enables development in a programming language (e.g., C/C++) • It is used for a lot of operations such as a) Compilation b) Preparing Libraries Most common toolchain is the c) Reading a binary file (or part of it) GNU toolchain which is part of d) Debugging the GNU project • Normally it contains a) Compiler : Generate object files from source code files b) Linker: Link object files together to build a binary file c) Library Archiver: To group a set of object files into a library file d) Debugger: To debug the binary file while running e) And other tools The GNU Toolchain GNU (GNU’s Not Unix) The GNU toolchain has played a vital role in the development of the Linux kernel, BSD, and software for embedded systems. The GNU project produced a set of programming tools. Parts of the toolchain we will use are: -gcc: (GNU Compiler Collection): suite of compilers for many programming languages -binutils: Suite of tools including linker (ld), assembler (gas) -gdb: Code debugging tool -libc: Subset of standard C library (assuming a C compiler). -bash: free Unix shell (Bourne-again shell). Default shell on GNU/Linux systems and Mac OSX. Also ported to Microsoft Windows. -make: automation tool for compilation and build Program development tools The process of converting source code to an executable binary image requires several steps, each with its own tool. -
The “Stabs” Debug Format
The \stabs" debug format Julia Menapace, Jim Kingdon, David MacKenzie Cygnus Support Cygnus Support Revision TEXinfo 2017-08-23.19 Copyright c 1992{2021 Free Software Foundation, Inc. Contributed by Cygnus Support. Written by Julia Menapace, Jim Kingdon, and David MacKenzie. Permission is granted to copy, distribute and/or modify this document under the terms of the GNU Free Documentation License, Version 1.3 or any later version published by the Free Software Foundation; with no Invariant Sections, with no Front-Cover Texts, and with no Back-Cover Texts. A copy of the license is included in the section entitled \GNU Free Documentation License". i Table of Contents 1 Overview of Stabs ::::::::::::::::::::::::::::::: 1 1.1 Overview of Debugging Information Flow ::::::::::::::::::::::: 1 1.2 Overview of Stab Format ::::::::::::::::::::::::::::::::::::::: 1 1.3 The String Field :::::::::::::::::::::::::::::::::::::::::::::::: 2 1.4 A Simple Example in C Source ::::::::::::::::::::::::::::::::: 3 1.5 The Simple Example at the Assembly Level ::::::::::::::::::::: 4 2 Encoding the Structure of the Program ::::::: 7 2.1 Main Program :::::::::::::::::::::::::::::::::::::::::::::::::: 7 2.2 Paths and Names of the Source Files :::::::::::::::::::::::::::: 7 2.3 Names of Include Files:::::::::::::::::::::::::::::::::::::::::: 8 2.4 Line Numbers :::::::::::::::::::::::::::::::::::::::::::::::::: 9 2.5 Procedures ::::::::::::::::::::::::::::::::::::::::::::::::::::: 9 2.6 Nested Procedures::::::::::::::::::::::::::::::::::::::::::::: 11 2.7 Block Structure -
Automatic Classifying of Mac OS X Samples
Automatic Classifying of Mac OS X Samples Spencer Hsieh, Pin Wu and Haoping Liu Trend Micro Inc., Taiwan TREND MICRO LEGAL DISCLAIMER The information provided herein is for general information Contents and educational purposes only. It is not intended and should not be construed to constitute legal advice. The information contained herein may not be applicable to all situations and may not reflect the most current situation. Nothing contained herein should be relied on or acted 4 upon without the benefit of legal advice based on the particular facts and circumstances presented and nothing Introduction herein should be construed otherwise. Trend Micro reserves the right to modify the contents of this document at any time without prior notice. Translations of any material into other languages are intended solely as a convenience. Translation accuracy 6 is not guaranteed nor implied. If any questions arise related to the accuracy of a translation, please refer to Mac OS X Samples Dataset the original language official version of the document. Any discrepancies or differences created in the translation are not binding and have no legal effect for compliance or enforcement purposes. 10 Although Trend Micro uses reasonable efforts to include accurate and up-to-date information herein, Trend Micro makes no warranties or representations of any kind as Classification of Mach-O Files to its accuracy, currency, or completeness. You agree that access to and use of and reliance on this document and the content thereof is at your own risk. Trend Micro disclaims all warranties of any kind, express or implied. 11 Neither Trend Micro nor any party involved in creating, producing, or delivering this document shall be liable for any consequence, loss, or damage, including direct, Malware Families indirect, special, consequential, loss of business profits, or special damages, whatsoever arising out of access to, use of, or inability to use, or in connection with the use of this document, or any errors or omissions in the content 15 thereof. -
Riscv-Software-Stack-Tutorial-Hpca2015
Software Tools Bootcamp RISC-V ISA Tutorial — HPCA-21 08 February 2015 Albert Ou UC Berkeley [email protected] Preliminaries To follow along, download these slides at http://riscv.org/tutorial-hpca2015.html 2 Preliminaries . Shell commands are prefixed by a “$” prompt. Due to time constraints, we will not be building everything from source in real-time. - Binaries have been prepared for you in the VM image. - Detailed build steps are documented here for completeness but are not necessary if using the VM. Interactive portions of this tutorial are denoted with: $ echo 'Hello world' . Also as a reminder, these slides are marked with an icon in the upper-right corner: 3 Software Stack . Many possible combinations (and growing) . But here we will focus on the most common workflows for RISC-V software development 4 Agenda 1. riscv-tools infrastructure 2. First Steps 3. Spike + Proxy Kernel 4. QEMU + Linux 5. Advanced Cross-Compiling 6. Yocto/OpenEmbedded 5 riscv-tools — Overview “Meta-repository” with Git submodules for every stable component of the RISC-V software toolchain Submodule Contents riscv-fesvr RISC-V Frontend Server riscv-isa-sim Functional ISA simulator (“Spike”) riscv-qemu Higher-performance ISA simulator riscv-gnu-toolchain binutils, gcc, newlib, glibc, Linux UAPI headers riscv-llvm LLVM, riscv-clang submodule riscv-pk RISC-V Proxy Kernel (riscv-linux) Linux/RISC-V kernel port riscv-tests ISA assembly tests, benchmark suite All listed submodules are hosted under the riscv GitHub organization: https://github.com/riscv 6 riscv-tools — Installation . Build riscv-gnu-toolchain (riscv*-*-elf / newlib target), riscv-fesvr, riscv-isa-sim, and riscv-pk: (pre-installed in VM) $ git clone https://github.com/riscv/riscv-tools $ cd riscv-tools $ git submodule update --init --recursive $ export RISCV=<installation path> $ export PATH=${PATH}:${RISCV}/bin $ ./build.sh . -
File Handling in Python
hapter C File Handling in 2 Python There are many ways of trying to understand programs. People often rely too much on one way, which is called "debugging" and consists of running a partly- understood program to see if it does what you expected. Another way, which ML advocates, is to install some means of understanding in the very programs themselves. — Robin Milner In this Chapter » Introduction to Files » Types of Files » Opening and Closing a 2.1 INTRODUCTION TO FILES Text File We have so far created programs in Python that » Writing to a Text File accept the input, manipulate it and display the » Reading from a Text File output. But that output is available only during » Setting Offsets in a File execution of the program and input is to be entered through the keyboard. This is because the » Creating and Traversing a variables used in a program have a lifetime that Text File lasts till the time the program is under execution. » The Pickle Module What if we want to store the data that were input as well as the generated output permanently so that we can reuse it later? Usually, organisations would want to permanently store information about employees, inventory, sales, etc. to avoid repetitive tasks of entering the same data. Hence, data are stored permanently on secondary storage devices for reusability. We store Python programs written in script mode with a .py extension. Each program is stored on the secondary device as a file. Likewise, the data entered, and the output can be stored permanently into a file. -
A Proposed System for Hiding Information in Portable Executable Files Based on Analyzing Import Section
IOSR Journal of Engineering (IOSRJEN) www.iosrjen.org ISSN (e): 2250-3021, ISSN (p): 2278-8719 Vol. 04, Issue 01 (January. 2014), ||V7|| PP 21-30 A Proposed System for Hiding Information In Portable Executable Files Based on Analyzing Import Section Mohammad Hussein Jawwad 1- University of Babylon- College of Information Technology- Iraq Abstract: - Information-hiding techniques have newly become very important in a many application areas. Many cover mediums have been used to hide information like image, video, voice. Use of these mediums have been extensively studied. In this paper, we propose new system for hiding information in Portable Executable files (PE files). PE is a file format for executable file used in the 32-bit and 64-bit versions of the Windows operating system. This algorithm has higher security than some traditional ones because of the combination between encryption and hiding. We first encrypt the information before hiding it to ensure high security. After that we hide the information in the import table of PE file. This hiding depends on analyzing the import table characteristics of PE files that have been built under Borland turbo assembler. The testing result shows that the result file does not make any inconsistency with anti-virus programs and the PE file still function as normal after the hiding process. Keywords: - PE File, Information Hiding, Cryptography. I. INTRODUCTION The development and wide use of computer science and informatics also, the advent of global networks (i.e. Internet) that make the access for information is possible for every one online impose the need for ways to avoid hackers and muggers from getting the important information. -
Chapter 10 Streams Streams Text Files and Binary Files
Streams Chapter 10 • A stream is an object that enables the flow of File I/O data between a ppgrogram and some I/O device or file – If the data flows into a program, then the stream is called an input stream – If the dtdata flows out of a program, then the stream is called an output stream Copyright © 2012 Pearson Addison‐Wesley. All rights reserved. 10‐2 Streams Text Files and Binary Files • Input streams can flow from the kbkeyboar d or from a • Files that are designed to be read by human beings, file and that can be read or written with an editor are – StSystem. in is an itinput stream tha t connects to the called text files keyboard – Scanner keyy(y);board = new Scanner(System.in); Text files can also be called ASCII files because the data they contain uses an ASCII encoding scheme • Output streams can flow to a screen or to a file – An advantage of text files is that the are usually the same – System.out is an output stream that connects to the screen on all computers, so tha t they can move from one System.out.println("Output stream"); computer to another Copyright © 2012 Pearson Addison‐Wesley. All rights reserved. 10‐3 Copyright © 2012 Pearson Addison‐Wesley. All rights reserved. 10‐4 Text Files and Binary Files Writing to a Text File • Files tha t are didesigne d to be read by programs and • The class PrintWriter is a stream class that consist of a sequence of binary digits are called binary files that can be used to write to a text file – Binary files are designed to be read on the same type of – An object of the class PrintWriter has the computer and with the same programming language as the computer that created the file methods print and println – An advantage of binary files is that they are more efficient – These are similar to the System.out methods to process than text files of the same names, but are used for text file – Unlike most binary files, Java binary files have the advantage of being platform independent also output, not screen output Copyright © 2012 Pearson Addison‐Wesley. -
Portable Executable File Format
Chapter 11 Portable Executable File Format IN THIS CHAPTER + Understanding the structure of a PE file + Talking in terms of RVAs + Detailing the PE format + The importance of indices in the data directory + How the loader interprets a PE file MICROSOFT INTRODUCED A NEW executable file format with Windows NT. This for- mat is called the Portable Executable (PE) format because it is supposed to be portable across all 32-bit operating systems by Microsoft. The same PE format exe- cutable can be executed on any version of Windows NT, Windows 95, and Win32s. Also, the same format is used for executables for Windows NT running on proces- sors other than Intel x86, such as MIPS, Alpha, and Power PC. The 32-bit DLLs and Windows NT device drivers also follow the same PE format. It is helpful to understand the PE file format because PE files are almost identi- cal on disk and in RAM. Learning about the PE format is also helpful for under- standing many operating system concepts. For example, how operating system loader works to support dynamic linking of DLL functions, the data structures in- volved in dynamic linking such as import table, export table, and so on. The PE format is not really undocumented. The WINNT.H file has several struc- ture definitions representing the PE format. The Microsoft Developer's Network (MSDN) CD-ROMs contain several descriptions of the PE format. However, these descriptions are in bits and pieces, and are by no means complete. In this chapter, we try to give you a comprehensive picture of the PE format. -
Automatic Porting of Binary File Descriptor Library
Automatic Porting of Binary File Descriptor Library Maghsoud Abbaspour+, Jianwen Zhu++ Technical Report TR-09-01 September 2001 + Electrical and Computer Engineering University of Tehran, Iran ++ 10 King's College Road Edward S. Rogers Sr. Electrical and Computer Engineering University of Toronto, Ontario M5S 3G4, Canada [email protected] [email protected] Abstract Since software is playing an increasingly important role in system-on-chip, retargetable compi- lation has been an active research area in the last few years. However, the retargetting of equally important downstream system tools, such as assemblers, linkers and debuggers, has either been ignored, or falls short of production quality due to the complexity involved in these tools. In this paper, we present a technique that can automatically retarget the GNU BFD library, the foundation library for a suite of binary tools. Other than having all the advantages enjoyed by open-source software by aligning to a de facto standard, our technique is systematic, as a result of using a formal model of abstract binary interface (ABI) as a new element of architectural model; and simple, as a result of leveraging free software to the largest extent. Contents 1 Introduction 1 2 Related Work 2 3 Binary File Descriptor Library (BFD) 3 4 ABI Modeling 5 5 Retargetting BFD 9 6 Implementation and Experiments 10 7 Conclusion 12 8 References 12 i 1 Introduction New products in consumer electronics and telecommunications are characterized by increasing functional complexity and shorter design cycle. It is generally conceived that the complexity problem can be best solved by the use of system-on-chip (SOC) technology. -
Common Object File Format (COFF)
Application Report SPRAAO8–April 2009 Common Object File Format ..................................................................................................................................................... ABSTRACT The assembler and link step create object files in common object file format (COFF). COFF is an implementation of an object file format of the same name that was developed by AT&T for use on UNIX-based systems. This format encourages modular programming and provides powerful and flexible methods for managing code segments and target system memory. This appendix contains technical details about the Texas Instruments COFF object file structure. Much of this information pertains to the symbolic debugging information that is produced by the C compiler. The purpose of this application note is to provide supplementary information on the internal format of COFF object files. Topic .................................................................................................. Page 1 COFF File Structure .................................................................... 2 2 File Header Structure .................................................................. 4 3 Optional File Header Format ........................................................ 5 4 Section Header Structure............................................................. 5 5 Structuring Relocation Information ............................................... 7 6 Symbol Table Structure and Content........................................... 11 SPRAAO8–April 2009 -
Investigation of Malicious Portable Executable File Detection on the Network Using Supervised Learning Techniques
Investigation of Malicious Portable Executable File Detection on the Network using Supervised Learning Techniques Rushabh Vyas, Xiao Luo, Nichole McFarland, Connie Justice Department of Information and Technology, Purdue School of Engineering and Technology IUPUI, Indianapolis, IN, USA 46202 Emails: [email protected]; [email protected]; [email protected]; [email protected] Abstract—Malware continues to be a critical concern for that random forest learning technique achieved best detection everyone from home users to enterprises. Today, most devices are performance than the other three learning techniques. The connected through networks to the Internet. Therefore, malicious achieved detection rate and false alarm rate on experimental code can easily and rapidly spread. The objective of this paper is to examine how malicious portable executable (PE) files can be data set were 98.7% and 1.8% respectively. We compared detected on the network by utilizing machine learning algorithms. the performances of the four learning techniques on four The efficiency and effectiveness of the network detection rely types of PE malware - backdoors, viruses, worms and trojans. on the number of features and the learning algorithms. In this The results showed that the same learning technique show work, we examined 28 features extracted from metadata, packing, the similar performance on different types of malwares. It imported DLLs and functions of four different types of PE files for malware detection. The returned results showed that the demonstrated the features that are extracted from the files have proposed system can achieve 98.7% detection rates, 1.8% false no bias for a specific type of malware.