Cut (Unix) Explained

cut
Author:	AT&T Bell Laboratories
Developer:	Various open-source and commercial developers
Operating System:	Unix, Unix-like, IBM i
Platform:	Cross-platform
Genre:	Command
License:	coreutils GPLv3+

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.

Extraction of line segments can typically be done by bytes (-b), characters (-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 zeroth 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.

History

The original Bell Labs version was written by Gottfried W. R. Luderer.^[1] ^[2] is part of the X/Open Portability Guide since issue 2 of 1987. It was inherited into the first version of POSIX.1 and the Single Unix Specification. It first appeared in AT&T System III UNIX in 1982.

The version of cut bundled in GNU coreutils was written by David M. Ihnat, David MacKenzie, and Jim Meyering. The command is available as a separate package for Microsoft Windows as part of the UnxUtils collection of native Win32 ports of common GNU Unix-like utilities.^[3] The command has also been ported to the IBM i operating system.^[4]

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:theta: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

bar:ba

two:thha: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- filequuxfive:six:sevenepsilon:zeta:eta:theta:iota:kappa:lambda:muthe quick brown fox jumps over the lazy dog

(note that because the colon character is not found in the last line the entire line is shown)

Option -d specifies 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 presupposes usage of option -f.

To output the third field of each line using space as the field delimiter:$ cut -d " " -f 3 filefoo:bar:baz:qux:quuxone:two:three:four:five:six:sevenalpha:beta:gamma:delta:epsilon:zeta:eta:theta:iota:kappa:lambda:mubrown(Note that because the space character is not found in the first three lines these entire lines are shown.)

To separate two words having any delimiter:$ line=process.processid$ cut -d "." -f1 <<< $lineprocess$ cut -d "." -f2 <<< $lineprocessid

Syntax

cut [-b list] [-c list] [-f list] [-n] [-d delim] [-s] [file]

Flags which may be used include:

: Bytes; a list following specifies a range of bytes which will be returned, e.g. would return the first 66 bytes of a line. NB If used in conjunction with, no multi-byte characters will be split. NNB. will only work on input lines of less than 1023 bytes

External links

- Softpanorama cut page.
Cut out selected fields of each line of a file A portrait of cut(1) and its historical background.

Notes and References

Web site: cut(1) - OpenBSD manual pages.
Web site: [TUHS] A portrait of cut(1)]. 15 January 2020 .
Web site: Native Win32 ports of some GNU utilities. unxutils.sourceforge.net.
Web site: IBM System i Version 7.2 Programming Qshell . en . IBM . . IBM . 2020-09-05 . live. https://web.archive.org/web/20200918130823/https://www.ibm.com/support/knowledgecenter/ssw_ibm_i_74/rzahz/rzahzpdf.pdf?view=kc . 2020-09-18 .