"cut" Command

Learn all about cut command

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cut out selected portions of each line of a file. It is used for text processing; User can use this command to extract portion of text from a file. It can be used to cut parts of a line by byte position, character and delimiter. It can also be used to cut data from file formats like CSV.

root:~# man cut

For example, let's say user has a file named test.txt which contains the following text:

first1  second1 third1  fourth1 five1
first2  second2 third2  fourth2 five2
first3  second3 third3  fourth3 five3
first4  second4 third4  fourth4 five4

In following examples, each of these words is separated by a tab character, not spaces. The tab character is the default delimiter of cut, so it will by default consider a field to be anything delimited by a tab.

Example-1

1.1 cut data by using fields (-f)

To "cut" only the second field of each line use following command:

root:~# cut -f 2 test.txt
second1
second2
second3
second4

To "cut" second to fourth field of each line use following command:

root:~# cut -f 2-4 test.txt
second1    third1    fourth1
second2    third2    fourth2
second3    third3    fourth3
second4    third4    fourth4

To "cut" first to second and fourth to fifth field of each line use following command:

root:~# cut -f 1-2,4-5 test.txt
first1    second1    fourth1    five1
first2    second2    fourth2    five2
first3    second3    fourth3    five3
first4    second4    fourth4    five4

To "cut" the third field and every field after that, by omitting the first two fields; use following command:

root:~# cut -f 3- test.txt
third1    fourth1    five1
third2    fourth2    five2
third3    fourth3    five3
third4    fourth4    five4

Example-2

2.1 cut data by using characters (-c)

To "cut" only the fifth through fifteen character of every line, use following command:

root:~# cut -c 5-15 test.txt
t1    second1
t2    second2
t3    second3
t4    second4

To "cut" first 8 characters of every line, use following command:

cut -c -8 test.txt
first1    s
first2    s
first3    s
first4    s

2.2 cut data by using bytes (-b)

To "cut" only the fifth through fifteen bytes of every line, use following command:

root:# cut -b 5-15 test.txt
t1    second1
t2    second2
t3    second3
t4    second4

Example-3

3.1 Specify delimiter other than Tab (-d)

The tab character is the default delimiter that cut uses to determine what constitutes a field. There are many instances where delimiter is not tab but some other character and that can be used by following command:

root:~# cat /etc/passwd
root:x:0:0::/root:/bin/bash
other:x:0:0:root:/.other:/bin/bash
daemon:x:1:1:daemon:/usr/sbin:/bin/sh
bin:x:2:2:bin:/bin:/bin/sh
sys:x:3:3:sys:/dev:/bin/sh
sync:x:4:65534:sync:/bin:/bin/sync
man:x:6:12:man:/var/cache/man:/bin/sh
mail:x:8:8:mail:/var/mail:/bin/sh

root:~# cut -f 1 -d: /etc/passwd
root:0
other:0
daemon:1
bin:2
sys:3
sync:4
man:6
mail:8

Note: Delimiter can be only single character. If user tries to use more than single character as delimiter than cut will raise following error:

root:~# cut -f 1 -d'::' /etc/passwd
cut: the delimiter must be a single character
Try 'cut --help' for more information.

3.2 Change Output Delimiter for Display (--output-delimiter)

By Default the output delimiter is same as input delimiter that we specify in the -d option. To change the output delimiter use the option --output-delimiter as shown below.

root:~# cut -f 1,3 -d: /etc/passwd --output-delimiter='#'
root#0
other#0
daemon#1
bin#2
sys#3
sync#4
man#6
mail#8

To use delimiter as newline, user need to give $'\n' as shown below:

root:~# cut -f 1,3 -d: /etc/passwd --output-delimiter=$'\n'
root
0
other
0
daemon
1
bin
2
sys
3
sync
4
man
6
mail
8

Example-4

4.1 Select All Fields except specified ones (--complement)

There are instances where user wants to complement the selection field list. The following example displays all the fields except field 7.

root:~# cut -d':' -f 7 /etc/passwd
/bin/bash
/bin/bash
/bin/sh
/bin/sh
/bin/sh
/bin/sync
/bin/sh
/bin/sh

root:~# cut -d':' -f 7 /etc/passwd --complement
root:x:0:0::/root
other:x:0:0:root:/.other
daemon:x:1:1:daemon:/usr/sbin
bin:x:2:2:bin:/bin
sys:x:3:3:sys:/dev
sync:x:4:65534:sync:/bin
man:x:6:12:man:/var/cache/man
mail:x:8:8:mail:/var/mail

4.2 do not print lines not containing delimiters (--only-delimited or -s)

By default, cut will print whole line if it doesnt find delimiter in the line. But it's possible to filter and display only the lines that contains the specified delimiter.

root:~# cut -d'~' -f 1 /etc/passwd
root:x:0:0::/root:/bin/bash
other:x:0:0:root:/.other:/bin/bash
daemon:x:1:1:daemon:/usr/sbin:/bin/sh
bin:x:2:2:bin:/bin:/bin/sh
sys:x:3:3:sys:/dev:/bin/sh
sync:x:4:65534:sync:/bin:/bin/sync
man:x:6:12:man:/var/cache/man:/bin/sh
mail:x:8:8:mail:/var/mail:/bin/sh

root:~# cut -d'~' -f 1 /etc/passwd -s
root:~#