Cut (Unix)
Encyclopedia
In computing
, cut is a Unix
command line utility which is used to extract sections from each line of input — usually from a file
.
Extraction of line segments can typically be done by byte
s (
s (
value). Since version 6, an error is thrown if you include a zeroth value. Prior to this the value was ignored and assumed to be 1.
foo:bar:baz:qux:quux
one:two:three:four:five:six:seven
alpha:beta:gamma:delta:epsilon:zeta:eta:teta:iota:kappa:lambda:mu
the quick brown fox jumps over the lazy dog
To output the fourth through tenth characters of each line:
% cut -c 4-10 file
This gives the output:
:bar:ba
:two:th
ha:beta
quick
To output the fifth field through the end of the line of each line using the colon character
as the field delimiter:
% cut -d ":" -f 5- file
This gives the output:
quux
five:six:seven
epsilon:zeta:eta:teta:iota:kappa:lambda:mu
the quick brown fox jumps over the lazy dog
(note that as the colon character
is not found in the last line the entire line is shown)
Option -d specified a single character delimiter (in the example above it is a colon) which serves as field separator. option -f which specifies range of fields included in the output (here fields range from five till the end ). Option -d presuppose usage of option -f.
To output the third field of each line using space as the field delimiter:
%cut -d " " -f 3 file
This gives the output:
foo:bar:baz:qux:quux
one:two:three:four:five:six:seven
alpha:beta:gamma:delta:epsilon:zeta:eta:teta:iota:kappa:lambda:mu
brown
(note that as the space character is not found in the first three lines these entire lines are shown)
Computing
Computing is usually defined as the activity of using and improving computer hardware and software. It is the computer-specific part of information technology...
, cut is a Unix
Unix
Unix is a multitasking, multi-user computer operating system originally developed in 1969 by a group of AT&T employees at Bell Labs, including Ken Thompson, Dennis Ritchie, Brian Kernighan, Douglas McIlroy, and Joe Ossanna...
command line utility which is used to extract sections from each line of input — usually from a file
Computer file
A computer file is a block of arbitrary information, or resource for storing information, which is available to a computer program and is usually based on some kind of durable storage. A file is durable in the sense that it remains available for programs to use after the current program has finished...
.
Extraction of line segments can typically be done by byte
Byte
The byte is a unit of digital information in computing and telecommunications that most commonly consists of eight bits. Historically, a byte was the number of bits used to encode a single character of text in a computer and for this reason it is the basic addressable element in many computer...
s (
-b), characterCharacter (computing)
In computer and machine-based telecommunications terminology, a character is a unit of information that roughly corresponds to a grapheme, grapheme-like unit, or symbol, such as in an alphabet or syllabary in the written form of a natural language....
s (
-c), or fields (-f) separated by a delimiter (-d — the tab character by default). A range must be provided in each case which consists of one of N, N-M, N- (N to the end of the line), or -M (beginning of the line to M), where N and M are counted from 1 (there is no zerothZeroth
Zero-based numbering is numbering in which the initial element of a sequence is assigned the index 0, rather than the index 1 as is typical in everyday circumstances. Under zero-based numbering, the initial element is sometimes termed the zeroth element, rather than the first element; zeroth is a...
value). Since version 6, an error is thrown if you include a zeroth value. Prior to this the value was ignored and assumed to be 1.
Examples
Assuming a file named file containing the lines:foo:bar:baz:qux:quux
one:two:three:four:five:six:seven
alpha:beta:gamma:delta:epsilon:zeta:eta:teta:iota:kappa:lambda:mu
the quick brown fox jumps over the lazy dog
To output the fourth through tenth characters of each line:
% cut -c 4-10 file
This gives the output:
:bar:ba
:two:th
ha:beta
quick
To output the fifth field through the end of the line of each line using the colon character
Colon (punctuation)
The colon is a punctuation mark consisting of two equally sized dots centered on the same vertical line.-Usage:A colon informs the reader that what follows the mark proves, explains, or lists elements of what preceded the mark....
as the field delimiter:
% cut -d ":" -f 5- file
This gives the output:
quux
five:six:seven
epsilon:zeta:eta:teta:iota:kappa:lambda:mu
the quick brown fox jumps over the lazy dog
(note that as the colon character
Colon (punctuation)
The colon is a punctuation mark consisting of two equally sized dots centered on the same vertical line.-Usage:A colon informs the reader that what follows the mark proves, explains, or lists elements of what preceded the mark....
is not found in the last line the entire line is shown)
Option -d specified a single character delimiter (in the example above it is a colon) which serves as field separator. option -f which specifies range of fields included in the output (here fields range from five till the end ). Option -d presuppose usage of option -f.
To output the third field of each line using space as the field delimiter:
%cut -d " " -f 3 file
This gives the output:
foo:bar:baz:qux:quux
one:two:three:four:five:six:seven
alpha:beta:gamma:delta:epsilon:zeta:eta:teta:iota:kappa:lambda:mu
brown
(note that as the space character is not found in the first three lines these entire lines are shown)