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Nm (Unix)
nm (name mangling) is a Unix command used to dump the symbol table and their attributes from a binary executable file (including libraries, compiled object modules, shared-object files, and standalone executables). The output from nm distinguishes between various symbol types. For example, it differentiates between a function that is supplied by an object module and a function that is required by it. nm is used as an aid for debugging, to help resolve problems arising from name conflicts and C++ name mangling, and to validate other parts of the toolchain. This command is shipped with a number of later versions of Unix and similar operating systems including Plan 9. The GNU Project ships an implementation of nm as part of the GNU Binutils package. nm output sample /* * File name: test.c * For C code compile with: * gcc -c test.c * * For C++ code compile with: * g++ -c test.cpp */ int global_var; int global_var_init = 26; static int static_var; static int static_var ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dennis Ritchie
Dennis MacAlistair Ritchie (September 9, 1941 – October 12, 2011) was an American computer scientist. He is most well-known for creating the C programming language and, with long-time colleague Ken Thompson, the Unix operating system and B programming language. Ritchie and Thompson were awarded the Turing Award from the ACM in 1983, the Hamming Medal from the IEEE in 1990 and the National Medal of Technology from President Bill Clinton in 1999. Ritchie was the head of Lucent Technologies System Software Research Department when he retired in 2007. He was the "R" in K&R C, and commonly known by his username dmr. Personal life and career Dennis Ritchie was born in Bronxville, New York. His father was Alistair E. Ritchie, a longtime Bell Labs scientist and co-author of ''The Design of Switching Circuits'' on switching circuit theory. As a child, Dennis moved with his family to Summit, New Jersey, where he graduated from Summit High School. He graduated from Harvard Universi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Library (computing)
In computer science, a library is a collection of non-volatile memory, non-volatile resources used by computer programs, often for software development. These may include configuration data, documentation, help data, message templates, Code reuse, pre-written code and subroutines, Class (computer science), classes, Value (computer science), values or Data type, type specifications. In OS/360 and successors, IBM's OS/360 and its successors they are referred to as Data set (IBM mainframe)#Partitioned datasets, partitioned data sets. A library is also a collection of implementations of behavior, written in terms of a language, that has a well-defined interface (computing), interface by which the behavior is invoked. For instance, people who want to write a higher-level program can use a library to make system calls instead of implementing those system calls over and over again. In addition, the behavior is provided for reuse by multiple independent programs. A program invokes the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Unix SUS2008 Utilities
Unix (; trademarked as UNIX) is a family of multitasking, multiuser computer operating systems that derive from the original AT&T Unix, whose development started in 1969 at the Bell Labs research center by Ken Thompson, Dennis Ritchie, and others. Initially intended for use inside the Bell System, AT&T licensed Unix to outside parties in the late 1970s, leading to a variety of both academic and commercial Unix variants from vendors including University of California, Berkeley (BSD), Microsoft (Xenix), Sun Microsystems (SunOS/Solaris), HP/ HPE (HP-UX), and IBM (AIX). In the early 1990s, AT&T sold its rights in Unix to Novell, which then sold the UNIX trademark to The Open Group, an industry consortium founded in 1996. The Open Group allows the use of the mark for certified operating systems that comply with the Single UNIX Specification (SUS). Unix systems are characterized by a modular design that is sometimes called the "Unix philosophy". According to this philosophy, th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Unix Programming Tools
Unix (; trademarked as UNIX) is a family of Computer multitasking, multitasking, multiuser computer operating systems that derive from the original AT&T Corporation, AT&T Unix, whose development started in 1969 at the Bell Labs research center by Ken Thompson, Dennis Ritchie, and others. Initially intended for use inside the Bell System, AT&T licensed Unix to outside parties in the late 1970s, leading to a variety of both academic and commercial Unix variants from vendors including University of California, Berkeley (Berkeley Software Distribution, BSD), Microsoft (Xenix), Sun Microsystems (SunOS/Solaris (operating system), Solaris), Hewlett-Packard, HP/Hewlett Packard Enterprise, HPE (HP-UX), and IBM (IBM AIX, AIX). In the early 1990s, AT&T sold its rights in Unix to Novell, which then sold the UNIX trademark to The Open Group, an industry consortium founded in 1996. The Open Group allows the use of the mark for certified operating systems that comply with the Single UNIX Spec ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Objdump
objdump is a command-line program for displaying various information about object files on Unix-like operating systems. For instance, it can be used as a disassembler to view an executable in assembly form. It is part of the GNU Binutils for fine-grained control over executables and other binary data. objdump uses the BFD library to read the contents of object files. Similar utilities are Borland TDUMP, Microsoft DUMPBIN and readelf. Note that on certain platforms (e.g. macOS), the objdump binary may actually be a link to llvm's objdump, with different command-line options and behavior. Example For example, $ objdump -D -M intel file.bin , grep main.: -A20 This performs disassembly on the file «file.bin», with the assembly code shown in Intel syntax. We then redirect it to grep, which searches the main function and displays 20 lines of its code. Example output: 4004ed: 55 push rbp 4004ee: 48 89 e5 mov rbp,rsp 4004f1: c7 45 ec ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Extern "C"
The C and C++ programming languages are closely related but have many significant differences. C++ began as a fork of an early, pre-standardized C, and was designed to be mostly source-and-link compatible with C compilers of the time. Due to this, development tools for the two languages (such as IDEs and compilers) are often integrated into a single product, with the programmer able to specify C or C++ as their source language. However, C is ''not'' a subset of C++, and nontrivial C programs will not compile as C++ code without modification. Likewise, C++ introduces many features that are not available in C and in practice almost all code written in C++ is not conforming C code. This article, however, focuses on differences that cause conforming C code to be ill-formed C++ code, or to be conforming/well-formed in both languages but to behave differently in C and C++. Bjarne Stroustrup, the creator of C++, has suggested that the incompatibilities between C and C++ should be red ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
GNU Compiler Collection
The GNU Compiler Collection (GCC) is an optimizing compiler produced by the GNU Project supporting various programming languages, hardware architectures and operating systems. The Free Software Foundation (FSF) distributes GCC as free software under the GNU General Public License (GNU GPL). GCC is a key component of the GNU toolchain and the standard compiler for most projects related to GNU and the Linux kernel. With roughly 15 million lines of code in 2019, GCC is one of the biggest free programs in existence. It has played an important role in the growth of free software, as both a tool and an example. When it was first released in 1987 by Richard Stallman, GCC 1.0 was named the GNU C Compiler since it only handled the C programming language. It was extended to compile C++ in December of that year. Front ends were later developed for Objective-C, Objective-C++, Fortran, Ada, D and Go, among others. The OpenMP and OpenACC specifications are also supported in the C and C ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
GNU Binutils
The GNU Binary Utilities, or , are a set of programming tools for creating and managing binary programs, object files, libraries, profile data, and assembly source code. Tools They were originally written by programmers at Cygnus Solutions. The GNU Binutils are typically used in conjunction with compilers such as the GNU Compiler Collection (), build tools like , and the GNU Debugger (). Through the use of the Binary File Descriptor library (), most tools support the various object file formats supported by . Commands The include the following commands: elfutils Ulrich Drepper wrote , to partially replace GNU Binutils, purely for Linux and with support only for ELF and DWARF. It distributes three libraries with it for programmatic access. See also * GNU Core Utilities * GNU Debugger *ldd (Unix), list symbols imported by the object file; similar to * List of Unix commands *llvm provides similar set of tools * strace strace is a diagnostic, debugging and instructi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
GNU Project
The GNU Project () is a free software, mass collaboration project announced by Richard Stallman on September 27, 1983. Its goal is to give computer users freedom and control in their use of their computers and computing devices by collaboratively developing and publishing software that gives everyone the rights to freely run the software, copy and distribute it, study it, and modify it. GNU software grants these rights in its license. In order to ensure that the ''entire'' software of a computer grants its users all freedom rights (use, share, study, modify), even the most fundamental and important part, the operating system (including all its numerous utility programs) needed to be free software. According to its manifesto, the founding goal of the project was to build a free operating system, and if possible, "everything useful that normally comes with a Unix system so that one could get along without any software that is not free." Stallman decided to call this operating sy ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Operating System
An operating system (OS) is system software that manages computer hardware, software resources, and provides common services for computer programs. Time-sharing operating systems schedule tasks for efficient use of the system and may also include accounting software for cost allocation of processor time, mass storage, printing, and other resources. For hardware functions such as input and output and memory allocation, the operating system acts as an intermediary between programs and the computer hardware, although the application code is usually executed directly by the hardware and frequently makes system calls to an OS function or is interrupted by it. Operating systems are found on many devices that contain a computer from cellular phones and video game consoles to web servers and supercomputers. The dominant general-purpose personal computer operating system is Microsoft Windows with a market share of around 74.99%. macOS by Apple Inc. is in second place (14.84%), and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Toolchain
In software, a toolchain is a set of programming tools that is used to perform a complex software development task or to create a software product, which is typically another computer program or a set of related programs. In general, the tools forming a toolchain are executed consecutively so the output or resulting environment state of each tool becomes the input or starting environment for the next one, but the term is also used when referring to a set of related tools that are not necessarily executed consecutively. A simple software development toolchain may consist of a compiler and linker (which transform the source code into an executable program), libraries (which provide interfaces to the operating system), and a debugger (which is used to test and debug created programs). A complex software product such as a video game needs tools for preparing sound effects, music, textures, 3-dimensional models and animations, together with additional tools for combining these resourc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Debugging
In computer programming and software development, debugging is the process of finding and resolving '' bugs'' (defects or problems that prevent correct operation) within computer programs, software, or systems. Debugging tactics can involve interactive debugging, control flow analysis, unit testing, integration testing, log file analysis, monitoring at the application or system level, memory dumps, and profiling. Many programming languages and software development tools also offer programs to aid in debugging, known as ''debuggers''. Etymology The terms "bug" and "debugging" are popularly attributed to Admiral Grace Hopper in the 1940s. While she was working on a Mark II computer at Harvard University, her associates discovered a moth stuck in a relay and thereby impeding operation, whereupon she remarked that they were "debugging" the system. However, the term "bug", in the sense of "technical error", dates back at least to 1878 and Thomas Edison who describes the "litt ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
