expand is a program that converts
tab characters into groups of
space
Space is a three-dimensional continuum containing positions and directions. In classical physics, physical space is often conceived in three linear dimensions. Modern physicists usually consider it, with time, to be part of a boundless ...
characters, while maintaining correct alignment. It is available in
Unix
Unix (, ; trademarked as 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, a ...
operating system
An operating system (OS) is system software that manages computer hardware and software resources, and provides common daemon (computing), services for computer programs.
Time-sharing operating systems scheduler (computing), schedule tasks for ...
s and many
Unix-like
A Unix-like (sometimes referred to as UN*X, *nix or *NIX) operating system is one that behaves in a manner similar to a Unix system, although not necessarily conforming to or being certified to any version of the Single UNIX Specification. A Uni ...
operating systems. The command is available as a separate package for
Microsoft Windows
Windows is a Product lining, product line of Proprietary software, proprietary graphical user interface, graphical operating systems developed and marketed by Microsoft. It is grouped into families and subfamilies that cater to particular sec ...
as part of the
UnxUtils
UnxUtils is a collection of utility programs that provide popular Unix-based shell commands ported from GNU implementations as native Windows programs that depend only on Win32 and the Microsoft C- runtime ( msvcrt.dll). The collection wa ...
collection of
native
Native may refer to:
People
* '' Jus sanguinis'', nationality by blood
* '' Jus soli'', nationality by location of birth
* Indigenous peoples, peoples with a set of specific rights based on their historical ties to a particular territory
** Nat ...
Win32
The Windows API, informally WinAPI, is the foundational application programming interface (API) that allows a computer program to access the features of the Microsoft Windows operating system in which the program is running. Programs can acces ...
ports Ports collections (or ports trees, or just ports) are the sets of makefiles and Patch (Unix), patches provided by the BSD-based operating systems, FreeBSD, NetBSD, and OpenBSD, as a simple method of installing software or creating binary packages. T ...
of common
GNU
GNU ( ) is an extensive collection of free software (394 packages ), which can be used as an operating system or can be used in parts with other operating systems. The use of the completed GNU tools led to the family of operating systems popu ...
Unix-like utilities.
Example
For example:
$ echo -e "foo\tbar" , expand , xxd -g 1 -u
0000000: 66 6F 6F 20 20 20 20 20 62 61 72 0A foo bar.
$ echo -e "foo\tbar" , xxd -g 1 -u
0000000: 66 6F 6F 09 62 61 72 0A foo.bar.
$
Here the
echo
In audio signal processing and acoustics, an echo is a reflection of sound that arrives at the listener with a delay after the direct sound. The delay is directly proportional to the distance of the reflecting surface from the source and the lis ...
command prints a string of text that includes a tab character, then the output is directed into the
expand command. The resulting output is then displayed in
hexadecimal
Hexadecimal (also known as base-16 or simply hex) is a Numeral system#Positional systems in detail, positional numeral system that represents numbers using a radix (base) of sixteen. Unlike the decimal system representing numbers using ten symbo ...
and as characters by the
xxd dump command. At the second prompt, the same
echo output is sent directly to the
xxd command. As can be seen by comparing the two, the
expand program converts the tab (specified as '\t' to the
echo program) into spaces.
See also
*
List of Unix commands
This is a list of the shell commands of the most recent version of the Portable Operating System Interface (POSIX) IEEE Std 1003.1-2024 which is part of the Single UNIX Specification (SUS). These commands are implemented in many shells on moder ...
*
Unexpand
unexpand is a command in Unix and Unix-like operating systems. It is used to convert groups of space characters into tab characters.
For example:
$ echo " asdf sdf" , unexpand , od -c
0000000 \t \t a s d f ...
References
External links
*
{{Core Utilities commands
Standard Unix programs
Unix SUS2008 utilities