Coreutils

The GNU Core Utilities is a package of GNU software containing the basic tools for Unix-like operating systems.

File utilities

chcon

changes file security context (SELinux);

chgrp

changes file group ownership;

chown

changes file ownership;

chmod

changes the permissions of a file or directory;

cp

copies a file or directory;

dd

copies and converts a file;

df

shows disk free space on filesystems;

dir

is exactly like ls -C -b (files are by default listed in columns and sorted vertically);

dircolors

setup color for ls;

install

copies files and sets attributes;

ln

creates a link to a file;

ls

lists directory contents;

mkdir

creates a directory;

mkfifo

makes named pipes (FIFOs);

mknod

makes block or character special files;

mktemp

creates a temporary file or directory;

mv

moves or renames files;

rm

removes (deletes) files;

rmdir

removes empty directories;

shred

overwrites a file to hide its contents, and optionally deletes it (may be not effective in some cases or with some filesystems, e.g., ext3, ext4, btrfs, reiser, xfs, ...);

sync

flushes file system buffers;

touch

changes file's timestamps;

truncate

shrinks or extends the size of a file to the specifed size;

vdir

is exactly like ls -l -b (files are by default listed in long format);

Text utilities

base64

base64 encode/decode data and print to standard output;

cat

concatenates and prints files on the stdout;

cksum

checksums and count the bytes in a file;

comm

compares two sorted files line by line;

csplit

splits a file into sections determined by context lines;

cut

removes sections from each line of files;

expand

converts tabs to spaces;

fmt

simple optimal text formatter;

fold

wraps each input line to fit in specified width;

head

outputs the first 10 lines of a file to stdout;

join

joins lines of two files on a common field;

md5sum

computes and checks MD5 message digest;

nl

numbers lines of files;

od

dumps files in octal and other formats;

paste

merges lines of files;

ptx

produces a permuted index of file contents;

pr

converts text files for printing;

sha1sum

sha224sum

sha256sum

sha384sum

sha512sum

computes and checks SHA-1, SHA-224, SHA-256, SHA-384, SHA-512 message digest;

shuf

generates random permutations;

sort

sorts lines of text files;

split

splits a file into pieces;

sum

checksums and counts the blocks in a file;

tac

concatenates and prints files in reverse;

tail

outputs the last 10 lines of a file;

tr

translates or deletes characters;

tsort

performs a topological sort;

unexpand

converts spaces to tabs;

uniq

removes duplicate lines from a sorted file;

wc

prints the number of bytes, words, and lines in a file;

Shell utilities

arch

prints machine hardware name (like uname -m);

basename

strips path prefix (directory) and suffix from filenames;

chroot

changes the root dir (i.e., allows to run cmd or interactive shell with special root dir);

date

prints/sets the system date and time;

dirname

strips last component (non-directory suffix) from the file name;

du

shows disk space usage on file systems;

echo

displays a specified line of text;

env

displays and modifies environment variables;

expr

evaluates expressions;

factor

factors numbers (e.g., factor 20 gives 2 2 5);

false

does nothing, but exits unsuccessfully (C lang defines EXIT_SUCCESS = 0, EXIT_FAILURE = 1);

groups

prints the groups of which the user is a member;

hostid

prints the numeric identifier for the current host (HEX);

id

prints real/effective UID and GID;

link

creates a link to a file;

logname

prints the user's login name;

nice

modifies the scheduling priority;

nohup

allows a cmd to continue running after logging out;

pathchk

checks whether file names are valid or portable;

pinky

a lightweight version of finger;

printenv

prints environment variables (e.g., printenv PATH);

printf

formats and prints data;

pwd

prints the current working directory;

readlink

displays value of a symbolic link;

runcon

run cmd with the specified security context;

seq

prints a sequence of numbers;

sleep

delays for a specified amount of time;

stat

returns data about an inode;

stty

changes and prints terminal line settings;

su

runs a shell or cmd with substitute user and group IDs;

tee

sends output to multiple files;

test

evaluates an expression;

timeout

runs cmd with a time limit;

true

does nothing, but exits successfully (EXIT_SUCCESS = 0);

tty

prints terminal name;

uname

prints misc system information;

unlink

removes the specified file using the unlink function (e.g., unlink msg2.txt);

uptime

tells how long the system has been running;

users

prints the user names of users currently logged in to the current host;

who

prints a list of all users currently logged in;

whoami

prints the effective userid;

yes

outputs a string repeatedly until killed by CTRL+C;