Core utilities

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Core utilities are the basic, fundamental tools of a GNU/Linux system. This article provides an incomplete overview of them, links their documentation and describes useful alternatives. The scope of this article includes, but is not limited to, the GNU coreutils. Most core utilities are traditional Unix tools and many were standardized by POSIX but have been developed further to provide more features.

Most command-line interfaces are documented in man pages, utilities by the GNU Project are documented primarily in Info manuals, some shells provide a help command for shell builtin commands. Additionally most utilities print their usage when run with the --help flag.


The following table lists some important utilities which Arch Linux users should be familiar with. See also intro(1).

Package Utility Description Documentation Alternatives
shell built-ins cd change directory cd(1p) #cd alternatives
GNU coreutils ls list directory ls(1), info tree, #ls alternatives
cat concatenate files to stdout cat(1), info tac(1), #cat alternatives
mkdir make directory mkdir(1), info
rmdir remove empty directory rmdir(1), info
rm remove files or directories rm(1), info shred unlink(1)
cp copy files or directories cp(1), info #cp alternatives
mv move files or directories mv(1), info
ln make hard or symbolic links ln(1), info sln(8) (soname recovery)
chown change file owner and group chown(1), info chgrp(1)
chmod change file permissions chmod(1), info
dd convert and copy a file dd(1), info #dd alternatives
df report file system disk space usage df(1), info #df alternatives
du estimate disk space used by files and directories du(1), info #du alternatives
GNU tar tar tar archiver tar(1), info archivers
GNU less less terminal pager less(1) terminal pagers
GNU findutils find search files or directories find(1), info, GregsWiki #find alternatives
GNU diffutils diff compare files line by line diff(1), info #diff alternatives
GNU grep grep print lines matching a pattern grep(1), info #grep alternatives
GNU sed sed stream editor sed(1), info, one-liners sad, sd
GNU AWK (gawk) AWK pattern scanning and processing language gawk(1), info AWK#Alternative implementations
util-linux dmesg print or control the kernel ring buffer dmesg(1) systemd journal
lsblk list block devices lsblk(8)
mount mount a filesystem mount(8)
umount unmount a filesystem umount(8)
su substitute user su(1) sudo, doas
kill terminate a process kill(1) pkill(1), killall(1)
procps-ng pgrep look up processes by name or attributes pgrep(1) pidof(1)
ps show information about processes ps(1) top(1), task managers
free display amount of free and used memory free(1)

Preventing data loss

rm, mv, cp and shell redirections happily delete or overwrite files without asking. rm, mv, and cp all support the -i flag to prompt the user before every removal / overwrite. Some users like to enable the -i flag by default using aliases. Relying upon these shell options can be dangerous, because you get used to them, resulting in potential data loss when you use another system or user that does not have them. The best way to prevent data loss is to create backups.


This table lists core utilities that often come in handy.

Package Utility Description Documentation Alternatives
shell built-ins alias define or display aliases alias(1p)
type print the type of a command type(1p) command(1p), whereis(1), which(1)
time time a command time(1p)
GNU coreutils tee read stdin and write to stdout and files tee(1), info pee(1)
mktemp make a temporary file or directory mktemp(1), info
mknod create named pipe or device node mknod(1), mkfifo(1), info
truncate shrink or extend the size of a file truncate(1), info fallocate(1)
basenc encoding input and output it basenc(1), base64(1), info
cut print selected parts of lines cut(1), info colrm(1), hck, choose
tr translate or delete characters tr(1), info uconv(1)
od dump files in octal and other formats od(1), info hexdump(1), vim's xxd(1)
sort sort lines sort(1), info
uniq report or omit repeated lines uniq(1), info anewer, runiqAUR, huniq-gitAUR
comm compare two sorted files line by line comm(1), info zetAUR
head output the first part of files head(1), info
join join lines of two inputs on a common field join(1), info combine(1) zetAUR
md5sum calculate cryptography hash functions of inputs and output sha256sum(1), sha512sum(1), info shasum(1), hashdeep(1), rhash(1)
tail output the last part of files, or follow files tail(1), info
wc print newline, word and byte count wc(1), info
GNU binutils strings print printable characters in binary files strings(1), info stringsextAUR
util-linux column columnate file, optionally pretty-printing in table with grid column(1) paste(1), csviewAUR
GNU findutils xargs combine or template arguments from stdin to invoke external command xargs(1) parallel(1) (parallel_alternatives(7))
GNU glibc iconv convert character encodings iconv(1) recode, uconv(1)
GNU sharutils uudecode encode file into email friendly text uuencode(1), uudecode(1), info uudeview(1)
file file guess file type file(1)

The moreutils package provides useful tools like sponge(1) that are missing from the GNU coreutils.


Alternative core utilities are provided by the following packages:

  • BusyBox — Utilities for rescue and embedded systems. || busybox
  • Toybox — An all-in-one Linux command line. || toyboxAUR
  • uutils — Cross-platform Rust rewrite of the GNU coreutils. || uutils-coreutils
  • Heirloom Toolchest — Traditional implementations of standard Unix utilities. || heirloom-shAUR, heirloom-doctoolsAUR
  • 9base — A port of various original Plan9 tools to unix. || 9base
  • sbase — A suckless variant of the *nix core utilities. || sbase-gitAUR
  • ubase — An extension of the sbase utilities. || ubase-gitAUR

cat alternatives

  • bat — A cat clone with syntax highlighting and Git integration. || bat

cd alternatives

  • zoxide — A smart cd command that learns your habits, allowing you to navigate anywhere in just a few keystrokes. || zoxide
  • autojump — A faster way to navigate your filesystem from the command line. || autojumpAUR

See also Bash#Auto "cd" when entering just a path and Zsh#Remembering recent directories.

cp alternatives

Using rsync#As cp/mv alternative allows you to resume a failed transfer, to show the transfer status, to skip already existing files and to make sure of the destination files integrity using checksums.

ls alternatives

  • broot — A new way to see and navigate directory trees. || broot
  • clifm — A file manager that can list files like ls(1) would (plus icons and RGB colors support). || clifmAUR
  • eza — Another ls replacement with color support, tree view, git integration and other features. Based on exa, which is no longer supported. || eza
  • lsd — Modern ls with a lot of pretty colors and awesome icons. || lsd

find alternatives

  • fd — Simple, fast and user-friendly alternative to find. Ignores hidden and .gitignore'd files by default. || fd
  • fuzzy-find — Fuzzy completion for finding files. || ff-gitAUR
  • mlocate — Merging locate/updatedb implementation. || mlocate
  • plocate — A much faster locate. || plocate
  • rawhide — find files using pretty C expressions. || rawhideAUR

For graphical file searchers, see List of applications/Utilities#File searching.

diff alternatives

While diffutils does not provide a word-wise diff, several other programs do:

  • git diff can do a word diff with --color-words, using --no-index it can also be used for files outside of Git working trees.
  • cwdiff — A GNU wdiff wrapper that colorizes the output. || cwdiffAUR
  • git-delta — A syntax-highlighting pager for git, diff, and grep output. || git-delta
  • dwdiff — A word diff front-end for the diff program; supports colors. || dwdiffAUR
  • icdiff — A colorized diff tool written in Python. "Improved color diff" is meant to supplement normal diff use. || icdiffAUR
  • wdiff — A wordwise implementation of GNU diff; does not support colors. || wdiff

See also List of applications/Utilities#Comparison, diff, merge.

grep alternatives

  • mgrep — A multiline grep. || mgrepAUR
  • pdfgrep — A tool to search text in PDF files. || pdfgrep
  • ripgrep-all — Search in plain text and also in PDFs, E-Books, Office documents, zip, tar.gz. || ripgrep-all

Code searchers

These tools aim to replace grep for code search. They do recursive search by default, skip binary files and respect .gitignore.

  • ack — A Perl-based grep replacement, aimed at programmers with large trees of heterogeneous source code. || ack
  • ripgrep (rg) — A search tool that combines the usability of ag with the raw speed of grep. || ripgrep
  • The Silver Searcher (ag) — Code searching tool similar to ack, but faster. || the_silver_searcher
  • ugrep (ug) — Ultrafast grep with interactive user interface, fuzzy search, boolean queries, hexdumps and more. || ugrep

See also: cscope.

Interactive filters

  • fzf — General-purpose command-line fuzzy finder, powered by find by default. || fzf
  • fzy — A fast, simple fuzzy text selector with an advanced scoring algorithm. || fzy
  • peco — Simplistic interactive filtering tool. || peco
  • percol — Adds flavor of interactive filtering to the traditional pipe concept of the UNIX shell. || percolAUR
  • skim — Fuzzy finder written in Rust, similar to fzf. || skim

dd alternatives

This article or section needs expansion.

Reason: ddrescue should be added to a list below and briefly described. Given the name similarity, it would be nice to mention the differences from dd_rescue. (Discuss in Talk:Core utilities)

See also: dd and ddrescue

Alternative dd implementations

This subsection lists dd implementations whose interface and default behaviour is mostly compliant with the POSIX specification of dd(1p).

  • ddpt — A portable rewrite of sg_dd(8) by the SCSI subsystem maintainer of the Linux kernel, with optional but very specialised hardware I/O (SCSI command sets) support, plus many other features. || ddptAUR
  • sdd — A dd implementation portable across UNIX environments by Joerg Schilling, that can checksum the copied data and retry reading bad blocks. || schily-tools-sddAUR
Spin-offs of GNU dd

The GNU implementation of dd found in coreutils also conforms to POSIX. This subsection lists its forks.

  • dcfldd — feature-enhanced fork of GNU dd for forensics and security scenarios, includes on-the-fly hashing capability, flexible wipes, write verification, output to multiple targets at the same time, split and piped output. || dcflddAUR
  • dc3dd — Another patched version of GNU dd from the United States Department of Defense Cyber Crime Center (DC3), with similar goals and features to dcfldd. || dc3ddAUR

Modernised dd analogues

This subsection lists dd alternatives that do not conform to POSIX (in terms of the JCL-resembling command-line syntax and default behaviour).

  • dd_rescue — A feature-packed, modernised dd analogue that is suitable for daily scripting, disk cloning, and data recovery. || dd_rescue
  • rw — Minimal and portable dd analogue with conventional command-line flags. || rwAUR

buffer spin-offs

This subsection lists forks of bufferAUR, a general-purpose I/O buffering utility similar to dd but has a dynamic-sized buffer. It supports blockwise I/O and can be used when dumping from/to an LTO-tape to avoid shoe shining.

  • mbuffer — Continuation of the buffer utility with threading and other features. || mbuffer

df alternatives

  • duf — A disk usage/free utility. || duf

du alternatives

  • cdu — du wrapper with colors and a pretty histogram. || cduAUR
  • dust — A more intuitive version of du, in Rust. || dust
  • dua — Fast disk usage analyzer, supports deleting files, written in Rust. || dua-cli
  • gdu — Disk usage analyzer with console interface, written in Go. || gdu
  • ncdu — An extremely lightweight and simple ncurses based disk usage analyzer, written in Zig. || ncdu

See also List of applications/Utilities#Disk usage display.

See also