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AWK (awk) is a domain-specific language designed for text processing and typically used as a data extraction and reporting tool. Like sed and grep, it is a filter, and is a standard feature of most Unix-like operating systems.
sed is a Unix utility that parses and transforms text, using a simple, compact programming language. sed 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. sed 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.
The C shell is a Unix shell created by Bill Joy while he was a graduate student at University of California, Berkeley in the late 1970s. It has been widely distributed, beginning with the 2BSD release of the Berkeley Software Distribution (BSD) which Joy first distributed in 1978. Other early contributors to the ideas or the code were Michael Ubell, Eric Allman, Mike O'Brien and Jim Kulp.
In software development, Make is a build automation tool that automatically builds executable programs and libraries from source code by reading files called Makefiles which specify how to derive the target program. Though integrated development environments and language-specific compiler features can also be used to manage a build process, Make remains widely used, especially in Unix and Unix-like operating systems.
Newline is a control character or sequence of control characters in a character encoding specification that is used to signify the end of a line of text and the start of a new one. Some text editors set this special character when pressing the ↵ Enter key.
The tab keyTab ↹ on a keyboard is used to advance the cursor to the next tab stop.
printf format string refers to a control parameter used by a class of functions in the input/output libraries of C and many other programming languages. The string is written in a simple template language: characters are usually copied literally into the function's output, but format specifiers, which start with a % character, indicate the location and method to translate a piece of data to characters.
xargs is a command on Unix and most Unix-like operating systems used to build and execute commands from standard input. It converts input from standard input into arguments to a command.
dc is a cross-platform reverse-polish calculator which supports arbitrary-precision arithmetic. Written by Robert Morris while at Bell Labs, it is one of the oldest Unix utilities, preceding even the invention of the C programming language. Like other utilities of that vintage, it has a powerful set of features but terse syntax. Traditionally, the bc calculator program was implemented on top of dc.
In computing, echo is a command that outputs the strings it is being passed 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.
In computing, cut is a command line utility on Unix and Unix-like operating systems which is used to extract sections from each line of input — usually from a file. It is currently part of the GNU coreutils package and the BSD Base System.
In computing, a here document is a file literal or input stream literal: it is a section of a source code file that is treated as if it were a separate file. The term is also used for a form of multiline string literals that use similar syntax, preserving line breaks and other whitespace in the text.
In Unix-like and some other operating systems, find is a command-line utility that locates files based on some user-specified criteria and then applies some requested action on each matched object.
In computing, a hex dump is a hexadecimal view of computer data, from RAM or from a computer file or storage device. Looking at a hex dump of data is usually done in the context of either debugging or reverse engineering.
fish is a Unix shell that attempts to be more interactive and user-friendly than those with a longer history or those formulated as function-compatible replacements for the aforementioned. The design goal of fish is to give the user a rich set of powerful features in a way that is easy to discover, remember, and use. fish is considered an "exotic shell", in that its syntax derives from neither the Bourne shell nor the C shell. Also unlike previous shells, which disable certain features by default to save system resources, fish enables all features by default.
In computing, sort is a standard command line program of Unix and Unix-like operating systems, that prints the lines of its input or concatenation of all files listed in its argument list in sorted order. Sorting is done based on one or more sort keys extracted from each line of input. By default, the entire input is taken as sort key. Blank space is the default field separator. The command supports a number of command-line options that can vary by implementation. For instance the "-r" flag will reverse the sort order.
expand is a program that converts tab characters into groups of space characters, while maintaining correct alignment. It is available in Unix operating systems and many Unix-like operating systems.
A batch file is a script file in DOS, OS/2 and Microsoft Windows. It consists of a series of commands to be executed by the command-line interpreter, stored in a plain text file. A batch file may contain any command the interpreter accepts interactively and use constructs that enable conditional branching and looping within the batch file, such as IF, FOR, and GOTO labels. The term "batch" is from batch processing, meaning "non-interactive execution", though a batch file may not process a batch of multiple data.
od is a command on various operating systems for displaying ("dumping") data in various human-readable output formats. The name is an acronym for "octal dump" since it defaults to printing in the octal data format.
Toybox is a free and open-source software implementation of over 200 Unix command line utilities such as ls, cp, and mv. The Toybox project was started in 2006, and became a BSD-licensed BusyBox alternative. Toybox is included with Android 6.0 "Marshmallow" and all later Android versions, and also used to build Android on Linux and macOS. All of the tools are tested on Linux, and many of them also work on BSD and macOS.
