cut Command in Linux with Examples

Description :

Print selected parts of lines from each FILE to standard output.

Usage :

cut [OPTION]… [FILE]…

Options :

-b, –bytes=LIST
output only these bytes
-c, –characters=LIST
output only these characters
-d, –delimiter=DELIM
use DELIM instead of TAB for field delimiter
-f, –fields=LIST
output only these fields; also print any line that contains no delimiter character, unless the -s option is specified
-n
with -b: don’t split multibyte characters
-s, –only-delimited
do not print lines not containing delimiters
–output-delimiter=STRING
use STRING as the output delimiter the default is to use the input delimiter
–help
display this help and exit
–version
output version information and exit

Use one, and only one of -b, -c or -f. Each LIST is made up of one range, or many ranges separated by commas. Each range is one of:

N
N’th byte, character or field, counted from 1
N-
from N’th byte, character or field, to end of line
N-M
from N’th to M’th (included) byte, character or field
-M
from first to M’th (included) byte, character or field

With no FILE, or when FILE is -, read standard input.

Examples :

For most of the example, we’ll be using the following test file.

$ cat test.txt
cat command for file oriented operations.
cp command for copy files or directories.
ls command to list out files and directories with its attributes.

1. Select Column of Characters

To extract only a desired column from a file use -c option.

$ cut -c5 test.txt
c
o
o

2. Select Column of Characters using Range

$ cut -c2-4 test.txt
at 
p c
s c

3. Select Column of Characters using either Start or End Position

$ cut -c2- test.txt
at command for file oriented operations.
p command for copy files or directories.
s command to list out files and directories with its attributes.

This example extracts from 2nd character to end of each line from test.txt file.

$ cut -c-2 test.txt
ca
cp
ls

This example extracts 2 characters from the beginning of each line from test.txt file.

4. Specifying delimiter

The following example displays only first field of each lines from /etc/passwd file using the field delimiter : (colon). In this case, the 1st field is the username.

$ cut -d':' -f1 /etc/passwd
root
daemon
bin
sys
sync
games
man
lp
mail
news
uucp
proxy
www-data
backup
list
irc
gnats
libuuid
syslog
messagebus
avahi-autoipd
usbmux
dnsmasq
whoopsie
kernoops
rtkit
speech-dispatcher
lightdm
avahi
colord
pulse
hplip
saned
abc
nobody

5. Select Multiple Fields from a File

Below example displays username and home directory of users who has the login shell as “/bin/bash”.

$ grep "/bin/bash" /etc/passwd | cut -d':' -f1,6
root:/root
abc:/home/abc

6. Select All Fields Except the Specified Fields

The following example displays all the fields from /etc/passwd file except field 7

$ grep "/bin/bash" /etc/passwd | cut -d':' --complement -s -f7
root:x:0:0:root:/root
abc:x:1000:1000:abc,,,:/home/abc

7. Change Output Delimiter for Display
To change the output delimiter use the option –output-delimiter as shown below. In this example, the input delimiter is : (colon), but the output delimiter is # (hash).

$ grep "/bin/bash" /etc/passwd | cut -d':'  -s -f1,6,7 --output-delimiter='#'
root#/root#/bin/bash
abc#/home/abc#/bin/bash

If output delimiter is new line, then output for a single user will be

$ grep abc /etc/passwd | cut -d':' -f1,6,7 --output-delimiter=$'\n'
abc
/home/abc
/bin/bash

8. Select Fields Only When a Line Contains the Delimiter

In our /etc/passwd example, if you pass a different delimiter other than : (colon), cut will just display the whole line.

In the following example, we’ve specified the delimiter as | (pipe), and cut command simply displays the whole line, even when it doesn’t find any line that has | (pipe) as delimiter.

$ grep "/bin/bash" /etc/passwd | cut -d'|'  -f1
root:x:0:0:root:/root:/bin/bash
abc:x:1000:1000:abc,,,:/home/abc:/bin/bash

But, it is possible to filter and display only the lines that contains the specified delimiter using -s option.

The following example doesn’t display any output, as the cut command didn’t find any lines that has | (pipe) as delimiter in the /etc/passwd file.

$ grep "/bin/bash" /etc/passwd | cut -d'|' -s -f1

9. Create a new file that contained just the username (field 1) and the user ID (UID)

$ cut -d: -f 1,3 /etc/passwd > uidpid.txt
$cat uidpid.txt
root:0
daemon:1
bin:2
sys:3
sync:4
games:5
man:6
lp:7
mail:8
news:9
uucp:10
proxy:13
www-data:33
backup:34
list:38
irc:39
gnats:41
libuuid:100
syslog:101
messagebus:102
avahi-autoipd:103
usbmux:104
dnsmasq:105
whoopsie:106
kernoops:107
rtkit:108
speech-dispatcher:109
lightdm:110
avahi:111
colord:112
pulse:113
hplip:114
saned:115
abc:1000
nobody:65534