As (Unix)

Last updated

as is a generic command name for an assembler on Unix.

Contents

Implementations

More than one assembler for Unix and Unix-like operating systems has been implemented with an executable called as. Users may be able to determine which implementation (if any) is present on their system by consulting the system's manuals, or by running as --version.

AT&T / Bell Labs

As of November 1971, an assembler invoked as as was available for Unix. Implemented by Bell Labs staff, it was based upon the Digital Equipment Corporation's PAL-11R assembler. [1] [2]

GNU Assembler

Circa 1986, the GNU Assembler ("GAS") became available. [3] As with the original UNIX assembler, GAS's executable is simply named as. [3] As of 2018, GAS implements many features that were not present in the 1971 Bell Labs implementation.

Related Research Articles

ed (software) Line-oriented text editor for Unix

ed is a line editor for Unix and Unix-like operating systems. It was one of the first parts of the Unix operating system that was developed, in August 1969. It remains part of the POSIX and Open Group standards for Unix-based operating systems, alongside the more sophisticated full-screen editor vi.

sed Standard UNIX utility for editing streams of data

sed is a Unix utility that parses and transforms text, using a simple, compact programming language. It was developed from 1973 to 1974 by Lee E. McMahon of Bell Labs, and is available today for most operating systems. sed was based on the scripting features of the interactive editor ed and the earlier qed. It was one of the earliest tools to support regular expressions, and remains in use for text processing, most notably with the substitution command. Popular alternative tools for plaintext string manipulation and "stream editing" include AWK and Perl.

troff, short for "typesetter roff", is the major component of a document processing system developed by Bell Labs for the Unix operating system. troff and the related nroff were both developed from the original roff.

<span class="mw-page-title-main">Unix shell</span> Command-line interpreter for Unix operating system

A Unix shell is a command-line interpreter or shell that provides a command line user interface for Unix-like operating systems. The shell is both an interactive command language and a scripting language, and is used by the operating system to control the execution of the system using shell scripts.

Yacc is a computer program for the Unix operating system developed by Stephen C. Johnson. It is a lookahead left-to-right rightmost derivation (LALR) parser generator, generating a LALR parser based on a formal grammar, written in a notation similar to Backus–Naur form (BNF). Yacc is supplied as a standard utility on BSD and AT&T Unix. GNU-based Linux distributions include Bison, a forward-compatible Yacc replacement.

<i>A Commentary on the UNIX Operating System</i> Book

A Commentary on the Sixth Edition UNIX Operating System by John Lions is a highly influential 1976 publication containing analytical commentary on the source code of the 6th Edition Unix computer operating system "resident nucleus" software, plus copy formatted and indexed by Lions, of said source code obtained from the authors at AT&T Bell Labs.

grep is a command-line utility for searching plaintext datasets for lines that match a regular expression. Its name comes from the ed command g/re/p, which has the same effect. grep was originally developed for the Unix operating system, but later available for all Unix-like systems and some others such as OS-9.

uniq is a utility command on Unix, Plan 9, Inferno, and Unix-like operating systems which, when fed a text file or standard input, outputs the text with adjacent identical lines collapsed to one, unique line of text.

man page Unix software documentation

A man page is a form of software documentation usually found on a Unix or Unix-like operating system. Topics covered include computer programs, formal standards and conventions, and even abstract concepts. A user may invoke a man page by issuing the man command.

In software development, Make is a command-line interface (CLI) software tool that performs actions ordered by configured dependencies as defined in a configuration file called a makefile. It is commonly used for build automation to build executable code from source code. But, not limited to building, Make can perform any operation available via the operating system shell.

pwd Directory information command on various operating systems

In Unix-like and some other operating systems, the pwd command writes the full pathname of the current working directory to the standard output.

The Unix command su, which stands for 'substitute user', is used by a computer user to execute commands with the privileges of another user account. When executed it invokes a shell without changing the current working directory or the user environment.

tr (Unix) Unix text formatting utility

tr is a command in Unix, Plan 9, Inferno, and Unix-like operating systems. It is an abbreviation of translate or transliterate, indicating its operation of replacing or removing specific characters in its input data set.

In computing, echo is a command that outputs the strings that are passed to it as arguments. It is a command available in various operating system shells and typically used in shell scripts and batch files to output status text to the screen or a computer file, or as a source part of a pipeline.

The GNU Assembler, commonly known as gas or as, is the assembler developed by the GNU Project. It is the default back-end of GCC. It is used to assemble the GNU operating system and the Linux kernel, and various other software. It is a part of the GNU Binutils package.

<span class="mw-page-title-main">Pipeline (Unix)</span> Mechanism for inter-process communication using message passing

In Unix-like computer operating systems, a pipeline is a mechanism for inter-process communication using message passing. A pipeline is a set of processes chained together by their standard streams, so that the output text of each process (stdout) is passed directly as input (stdin) to the next one. The second process is started as the first process is still executing, and they are executed concurrently.

rm (Unix) Unix command utility

rm is a basic command on Unix and Unix-like operating systems used to remove objects such as computer files, directories and symbolic links from file systems and also special files such as device nodes, pipes and sockets, similar to the del command in MS-DOS, OS/2, and Microsoft Windows. The command is also available in the EFI shell.

UNIX/32V is an early version of the Unix operating system from Bell Laboratories, released in June 1979. 32V was a direct port of the Seventh Edition Unix to the DEC VAX architecture.

<span class="mw-page-title-main">History of Unix</span> Operating system

The history of Unix dates back to the mid-1960s, when the Massachusetts Institute of Technology, AT&T Bell Labs, and General Electric were jointly developing an experimental time-sharing operating system called Multics for the GE-645 mainframe. Multics introduced many innovations, but also had many problems. Bell Labs, frustrated by the size and complexity of Multics but not its aims, slowly pulled out of the project. Their last researchers to leave Multics – among them Ken Thompson, Dennis Ritchie, Doug McIlroy, and Joe Ossanna – decided to redo the work, but on a much smaller scale.

<span class="mw-page-title-main">Unix</span> Family of computer operating systems

Unix is a family of multitasking, multi-user 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.

References

  1. "UNIX Programmers Manual" (PDF). Bitsavers.org. November 1971. Retrieved 31 December 2018.
  2. Dennis M. Ritchie. "UNIX Assembler Reference Manual" (PDF).
  3. 1 2 "The GNU Assembler". CiteSeerX   10.1.1.32.4503 .