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What does the Linux Cut command with practical examples refer to? for this question, this article introduces the corresponding analysis and solutions in detail, hoping to help more partners who want to solve this problem to find a simpler and easier way.

The cut command is used on Linux and Unix systems, cutting bytes, characters, and fields from each line of the file and writing them to standard output.

We will learn about Linux cut commands through some practical examples that you can use in your daily command-line activities.

Cut commands and syntax

The basic syntax for cut commands is as follows:

Cut OPTION... [FILE]...

Let's take a look at this option, and there is no option that this command does not work.

Clipping options:

-f: extract through the specified field. The cut command uses "TAB" as the default field delimiter.

The default delimiter is-ddisplacement Tab, which allows you to use a specific delimiter.

-b: extract by specifying a byte. You can also specify a byte range.

-c: split by character. This can be a comma-separated list of numbers or a range of numbers separated by a hyphen (-). -complement: used to supplement the selection

-output-delimiter: to change the output delimiter, use the option-output-delimiter = 'delimiter'.

-only-delimited:Cut will not output lines without delimiters

In this tutorial, we will use the following text file named "content.txt" and the / etc / passwd file to illustrate our example.

$cat content.txt Ubuntu LinuxMicrosoft WindowsOsX El CapitanUnixFreeBSD

How to cut with a delimiter

The most commonly used cut option is a combination of-d and-f, which basically extracts content based on specific delimiters and listed fields.

For example, the following only outputs the first field of each line in the'/ etc / passwd' file using the delimiter (:).

$cut-dazzlement'- F1 / etc/passwdrootbindaemonadmlpsyncshutdownhaltmailoperatorgames...

In the following example, we use a space ("") as the delimiter and remove the first field from the file named 'content.txt'.

$cut-d ""-f 1 content.txt UbuntuMicrosoftOsXUnixFreeBSD

This example extracts multiple fields from a specific file. Here, we use the colon (:) delimiter to extract the first and sixth fields from the file "/ etc / passwd", which contains the string "/ bin / bash":

$grep "/ bin/bash" / etc/passwd | cut-dazzlement'- F1 recorder 6 rootslax / rootslax / etc/passwd / rootslax

To display the field range, specify the start and end fields separated by hypen (-), as follows:

$grep "/ bin/bash" / etc/passwd | cut-dazzlement'- F1-4 Magic 6, 7 rootvans, 0lg0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 2, 0, 2, 0, 5, 2, 5, 2, 4, 4, 4, 4, 4, 5, 4, 4, 4, 5, 4, 4, 5, 4, 4, 5, 4, 5, 4, 4, 5, 4, 4, 5, 4, 5, 4, 4, 5, 4, 5, 4, 4, 5, 4, 5, 4, 5, 4, 4, 5, 4, 5, 4, 4, 5, 4, 4, 5, 4, 5, 4, 4, 5, 4, 4, 5, 4, 4, 4, 5, 4, 5, 4, 4, 5

How to supplement output selection

To supplement the list of selected fields, use the-complement option. This option is used to select all fields except the specified field.

In the following example command, all fields except the second field in the'/ etc / passwd' file are output:

$grep "/ bin/bash" / etc/passwd | cut-dazzlement'- complement-f2root:0:0:root:/root:/bin/bash

How to specify the output delimiter

To specify the output delimiter, use the-output-delimiter option. The input delimiter is specified by the-d option, and by default, the output delimiter is the same as the input separator.

Let's first take a look at the case where the output does not use output delimiters, as follows:

$cut-d:-F1 cut 7 / etc/passwd | sort | uniq-u_apt:/usr/sbin/nologinbackup:/usr/sbin/nologinbin:/usr/sbin/nologindaemon:/usr/sbin/nologindnsmasq:/usr/sbin/nologingames:/usr/sbin/nologingnats:/usr/sbin/nologinirc:/usr/sbin/nologinlandscape:/usr/sbin/nologinlist:/usr/sbin/nologinlp:/usr/sbin/nologinlxd:/bin/false

Now I have added the-output-delimiter option and replaced the input delimiter colon (:) with the output delimiter "SPACE", as follows:

$cut-d:-F1 etc/passwd 7-- output-delimiter'/ etc/passwd | sort | uniq-u_apt / usr/sbin/nologinbackup / usr/sbin/nologinbin / usr/sbin/nologindaemon / usr/sbin/nologindnsmasq / usr/sbin/nologingames / usr/sbin/nologingnats / usr/sbin/nologinirc / usr/sbin/nologinlandscape / usr/sbin/nologinlist / usr/sbin/nologinlp / usr/sbin/nologinlxd / bin/false

Let's look at another example, where we use the output delimiter to output on each field of the new line.

Here, we use-output-delimiter as $'\ npermission to represent the new line.

The output is as follows:

$grep root/ etc/passwd | cut-dazzlement'- F1 output-delimiter=$' 6, 7-- output-delimiter=$'\ n'root/root/bin/bashoperator/root/sbin/nologin

How to cut by character

Used to cut by character position. Remember, "TABS" and "space" are also considered characters.

To output the first character from each line of a file named content.txt, use the following command:

$cut-c 1 content.txtUMOUF

In the following example, we will display the characters 1 to 7 (range) for each line in the file:

$cut-c 1-7 content.txtUbuntuMicrosoOsX ElUnixFreeBSD

Let's see how to select a column by a specific start or end position.

To extract a column from the second character to the last character:

$cut-c2-content.txtbuntu Linuxicrosoft WindowssX El CapitannixreeBSD

To extract a column from the first character to the fourth character:

Cut-C muri 4 content.txtUbunMicrOsXUnixFree

How to cut by byte

Use the-b option to select a portion of a row by specifying the byte position with numbers separated by commas (,). Use hyphens to specify a byte range.

The following example cuts out the first, second, and third bytes of the file named "content.txt":

$cut-b 1jue 2je 3 content.txt UbuMicOsXUniFre

We can also list ranges using the following command:

$cut-b 1-3 content.txt Ubutu MicosoOsXEl UniFreBSD 5-7

Some practical examples

Cut is the most practical way to combine different Linux or Unix commands.

For example, you would use the ps command to extract "USER", "PID" and "COMMAND" as follows:

Ps-L u n | tr-s "| cut-d"-f 2pje 3e 1414USER PID COMMAND0 676 / sbin/agetty-o-p--\ u-keep-baud 115200 38400 ttyS0 vt2200 9600 ttyS0 vt2200 681 / sbin/agetty-o-p--\ u-noclear tty1 linux0 23174-bash0 26737 ps-L u n0 26738 tr-s0 26739 cut-d-f 2jue 3jue 14-

Let's give another example to extract the "total", "used", and "free" values of memory and save them to a text file using several commands:

$free-m | tr-s''| sed'/ ^ Memplet'| cut-d ""-f2-4 > > memory.txtOutput$ cat memory.txt985 86234

Conclusion

The cut command can be passed along with many other Linux or Unix commands. You can pass one or more filters through a pipe for other text processing.

One of the limitations of the cut command is that it does not support specifying multiple characters as delimiters. Multiple spaces are counted as multiple field delimiters, and you must use the tr command before cutting to get the desired output.

What is Linux system Linux is a free-to-use and free-spread UNIX-like operating system, is a POSIX-based multi-user, multi-task, multi-threaded and multi-CPU operating system, using Linux can run major Unix tools, applications and network protocols.

This is the answer to the question about what the Linux Cut command with practical examples refers to. I hope the above content can be of some help to you. If you still have a lot of doubts to be solved, you can follow the industry information channel for more related knowledge.

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