GNU Coreutils

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GNU Coreutils

This manual documents version 8.32 of the GNU core utilities, including the standard programs for text and file manipulation.

Copyright © 1994-2020 Free Software Foundation, Inc.

Permission is granted to copy, distribute and/or modify this document

under the terms of the GNU Free Documentation License, Version 1.3 or any later version published by the Free Software Foundation; with no Invariant Sections, with no Front-Cover Texts, and with no Back-Cover Texts. A copy of the license is included in the section entitled “GNU Free Documentation License”.

Introduction

  

Caveats, overview, and authors

Common options

  

Common options

Output of entire files

  

cat tac nl od base32 base64 basenc

Formatting file contents

  

fmt pr fold

Output of parts of files

  

head tail split csplit

Summarizing files

  

wc sum cksum b2sum md5sum sha1sum sha2

Operating on sorted files

  

sort shuf uniq comm ptx tsort

Operating on fields

  

cut paste join

Operating on characters

  

tr expand unexpand

Directory listing

  

ls dir vdir dircolors

Basic operations

  

cp dd install mv rm shred

Special file types

  

mkdir rmdir unlink mkfifo mknod ln link readlink

Changing file attributes

  

chgrp chmod chown touch

Disk usage

  

df du stat sync truncate

Printing text

  

echo printf yes

Conditions

  

false true test expr

Redirection

  

tee

File name manipulation

  

dirname basename pathchk mktemp realpath

Working context

  

pwd stty printenv tty

User information

  

id logname whoami groups users who

System context

  

date arch nproc uname hostname hostid uptime

SELinux context

  

chcon runcon

Modified command invocation

  

chroot env nice nohup stdbuf timeout

Process control

  

kill

Delaying

  

sleep

Numeric operations

  

factor numfmt seq

File permissions

  

Access modes

File timestamps

  

File timestamp issues

Date input formats

  

Specifying date strings

Version sort ordering

  

Details on version-sort algorithm

Opening the software toolbox

  

The software tools philosophy

GNU Free Documentation License

  

Copying and sharing this manual

Concept index

  

General index

Exit status

  

Indicating program success or failure

Backup options

  

Backup options

Block size

  

Block size

Floating point

  

Floating point number representation

Signal specifications

  

Specifying signals

Disambiguating names and IDs

  

chgrp, chown, chroot, id: user and group syntax

Random sources

  

Sources of random data

Target directory

  

Target directory

Trailing slashes

  

Trailing slashes

Traversing symlinks

  

Traversing symlinks to directories

Treating / specially

  

Treating / specially

Standards conformance

  

Standards conformance

Multi-call invocation

  

Multi-call program invocation

cat invocation

  

Concatenate and write files

tac invocation

  

Concatenate and write files in reverse

nl invocation

  

Number lines and write files

od invocation

  

Write files in octal or other formats

base32 invocation

  

Transform data into printable data

base64 invocation

  

Transform data into printable data

basenc invocation

  

Transform data into printable data

fmt invocation

  

Reformat paragraph text

pr invocation

  

Paginate or columnate files for printing

fold invocation

  

Wrap input lines to fit in specified width

head invocation

  

Output the first part of files

tail invocation

  

Output the last part of files

split invocation

  

Split a file into fixed-size pieces

csplit invocation

  

Split a file into context-determined pieces

wc invocation

  

Print newline, word, and byte counts

sum invocation

  

Print checksum and block counts

cksum invocation

  

Print CRC checksum and byte counts

b2sum invocation

  

Print or check BLAKE2 digests

md5sum invocation

  

Print or check MD5 digests

sha1sum invocation

  

Print or check SHA-1 digests

sha2 utilities

  

Print or check SHA-2 digests

sort invocation

  

Sort text files

shuf invocation

  

Shuffle text files

uniq invocation

  

Uniquify files

comm invocation

  

Compare two sorted files line by line

ptx invocation

  

Produce a permuted index of file contents

tsort invocation

  

Topological sort

General options in ptx

  

Options which affect general program behavior

Charset selection in ptx

  

Underlying character set considerations

Input processing in ptx

  

Input fields, contexts, and keyword selection

Output formatting in ptx

  

Types of output format, and sizing the fields

Compatibility in ptx

  

The GNU extensions to ptx

cut invocation

  

Print selected parts of lines

paste invocation

  

Merge lines of files

join invocation

  

Join lines on a common field

tr invocation

  

Translate, squeeze, and/or delete characters

expand invocation

  

Convert tabs to spaces

unexpand invocation

  

Convert spaces to tabs

Character sets

  

Specifying sets of characters

Translating

  

Changing one set of characters to another

Squeezing and deleting

  

Removing characters

ls invocation

  

List directory contents

dir invocation

  

Briefly list directory contents

vdir invocation

  

Verbosely list directory contents

dircolors invocation

  

Color setup for ls

Which files are listed

  

Which files are listed

What information is listed

  

What information is listed

Sorting the output

  

Sorting the output

General output formatting

  

General output formatting

Formatting the file names

  

Formatting the file names

cp invocation

  

Copy files and directories

dd invocation

  

Convert and copy a file

install invocation

  

Copy files and set attributes

mv invocation

  

Move (rename) files

rm invocation

  

Remove files or directories

shred invocation

  

Remove files more securely

link invocation

  

Make a hard link via the link syscall

ln invocation

  

Make links between files

mkdir invocation

  

Make directories

mkfifo invocation

  

Make FIFOs (named pipes)

mknod invocation

  

Make block or character special files

readlink invocation

  

Print value of a symlink or canonical file name

rmdir invocation

  

Remove empty directories

unlink invocation

  

Remove files via unlink syscall

chown invocation

  

Change file owner and group

chgrp invocation

  

Change group ownership

chmod invocation

  

Change access permissions

touch invocation

  

Change file timestamps

df invocation

  

Report file system disk space usage

du invocation

  

Estimate file space usage

stat invocation

  

Report file or file system status

sync invocation

  

Synchronize cached writes to persistent storage

truncate invocation

  

Shrink or extend the size of a file

echo invocation

  

Print a line of text

printf invocation

  

Format and print data

yes invocation

  

Print a string until interrupted

false invocation

  

Do nothing, unsuccessfully

true invocation

  

Do nothing, successfully

test invocation

  

Check file types and compare values

expr invocation

  

Evaluate expressions

File type tests

  

File type tests

Access permission tests

  

Access permission tests

File characteristic tests

  

File characteristic tests

String tests

  

String tests

Numeric tests

  

Numeric tests

String expressions

  

+ : match substr index length

Numeric expressions

  

+ - * / %

Relations for expr

  

| & < <= = == != >= >

Examples of expr

  

Examples of using expr

tee invocation

  

Redirect output to multiple files or processes

basename invocation

  

Strip directory and suffix from a file name

dirname invocation

  

Strip last file name component

pathchk invocation

  

Check file name validity and portability

mktemp invocation

  

Create temporary file or directory

realpath invocation

  

Print resolved file names

pwd invocation

  

Print working directory

stty invocation

  

Print or change terminal characteristics

printenv invocation

  

Print all or some environment variables

tty invocation

  

Print file name of terminal on standard input

Control

  

Control settings

Input

  

Input settings

Output

  

Output settings

Local

  

Local settings

Combination

  

Combination settings

Characters

  

Special characters

Special

  

Special settings

id invocation

  

Print user identity

logname invocation

  

Print current login name

whoami invocation

  

Print effective user ID

groups invocation

  

Print group names a user is in

users invocation

  

Print login names of users currently logged in

who invocation

  

Print who is currently logged in

arch invocation

  

Print machine hardware name

date invocation

  

Print or set system date and time

nproc invocation

  

Print the number of processors

uname invocation

  

Print system information

hostname invocation

  

Print or set system name

hostid invocation

  

Print numeric host identifier

uptime invocation

  

Print system uptime and load

Time conversion specifiers

  

%[HIklMNpPrRsSTXzZ]

Date conversion specifiers

  

%[aAbBcCdDeFgGhjmuUVwWxyY]

Literal conversion specifiers

  

%[%nt]

Padding and other flags

  

Pad with zeros, spaces, etc.

Setting the time

  

Changing the system clock

Options for date

  

Instead of the current time

Date input formats

  

Specifying date strings

Examples of date

  

Examples

chcon invocation

  

Change SELinux context of file

runcon invocation

  

Run a command in specified SELinux context

chroot invocation

  

Run a command with a different root directory

env invocation

  

Run a command in a modified environment

nice invocation

  

Run a command with modified niceness

nohup invocation

  

Run a command immune to hangups

stdbuf invocation

  

Run a command with modified I/O buffering

timeout invocation

  

Run a command with a time limit

kill invocation

  

Sending a signal to processes.

sleep invocation

  

Delay for a specified time

factor invocation

  

Print prime factors

numfmt invocation

  

Reformat numbers

seq invocation

  

Print numeric sequences

File timestamps

  

File timestamp issues

Mode Structure

  

Structure of file mode bits

Symbolic Modes

  

Mnemonic representation of file mode bits

Numeric Modes

  

File mode bits as octal numbers

Directory Setuid and Setgid

  

Set-user-ID and set-group-ID on directories

General date syntax

  

Common rules

Calendar date items

  

19 Dec 1994

Time of day items

  

9:20pm

Time zone items

  

EST, PDT, UTC, …

Combined date and time of day items

  

1972-09-24T20:02:00,000000-0500

Day of week items

  

Monday and others

Relative items in date strings

  

next tuesday, 2 years ago

Pure numbers in date strings

  

19931219, 1440

Seconds since the Epoch

  

@1078100502

Specifying time zone rules

  

TZ="America/New_York", TZ="UTC0"

Authors of parse_datetime

  

Bellovin, Eggert, Salz, Berets, et al.

Version sort overview

  

Implementation Details

  

Differences from the official Debian Algorithm

  

Advanced Topics

  

Toolbox introduction

  

Toolbox introduction

I/O redirection

  

I/O redirection

The who command

  

The who command

The cut command

  

The cut command

The sort command

  

The sort command

The uniq command

  

The uniq command

Putting the tools together

  

Putting the tools together

GNU Free Documentation License

  

Copying and sharing this manual

Next: Introduction, Up: (dir)   [Contents][Index]