Bash Shell Commands

Front 1

time {command}

Back 1

Will tell you how long the system took to execute the {command} command.

Front 2

pwd

Back 2

Displays the current working directory.

Front 3

set

Back 3

Used to customize the shell options for the Linux shell.

Front 4

exec {program}

Back 4

Used to execute a command when you want the command to replace the shell process. When the program terminates if will terminate the shell.

Front 5

./{program}

Back 5

Will run a program {program} inside of your current working directory.

Front 6

Shell Shortcuts: Ctrl+R

Back 6

Allows you to search the .history file.

Front 7

Shell Shortcuts: Ctrl+S

Back 7

Searches forward in the command history.

Front 8

Shell Shortcuts: Ctrl+G

Back 8

Terminates the search function (Esc does the same thing).

Front 9

Shell Shortcuts: Ctrl+P

Back 9

Does the same thing as the up arrow.

Front 10

Shell Shortcuts: Ctrl+N

Back 10

Does the same thing as the down arrow.

Front 11

Shell Shortcuts: Ctrl+A

Back 11

Move cursor to start of line.

Front 12

Shell Shortcuts: Ctrl+E

Back 12

Move cursor to end of line.

Front 13

Shell Shortcuts: Ctrl+B

Back 13

Move backward within a line.

Front 14

Shell Shortcuts: Ctrl+F

Back 14

Move forward within a line.

Front 15

Shell Shortcuts: Ctrl+D

Back 15

Deletes characters and moves down the line.

Front 16

Shell Shortcuts: Ctrl+K

Back 16

Deletes the entire line.

Front 17

Shell Shortcuts: Ctrl+X+Backspace

Back 17

Deletes all characters from cursor's current position back.

Front 18

Shell Shortcuts: Ctrl+T

Back 18

Transpose text - move characters down the line.

Front 19

Shell Shortcuts: Esc+c

Back 19

Converts the letter above the cursor to uppercase.

Front 20

Shell Shortcuts: Esc+u

Back 20

Converts the entire word above the cursor to uppercase.

Front 21

Shell Shortcuts: history -c

Back 21

Will clear all of your history. Good for trying to hide command line passwords entered.

Front 22

Shell Customization: User

Back 22

Each user home directory contains .bashrc and .profile as the main configuration files in bash.

Front 23

Shell Customization: Global

Back 23

/etc/profile and /etc/bash.bashrc are the global customizations for all user shells.

Front 24

export

Back 24

Used to set environmental variables at the command line (export VARIABLE={whatever})

Front 25

env

Back 25

Used to view all environmental variables.

Front 26

unset

Back 26

Used to delete an environmental variable (unset {VARIABLE NAME})

Front 27

Redirection Operators: <>

Back 27

Specified file will be used for standard input and standard output.

Front 28

Redirection Operators: <<

Back 28

Takes text as standard input.

Front 29

Redirection Operators: &>

Back 29

Creates a new file (or overwrites existing) for both standard output and standard error.

Front 30

Redirection Operators: 2>>

Back 30

Appends standard error to an already existing file. If the file does not exist it is created.

Front 31

Redirection Operators: 2>

Back 31

Creates or overwrites a file for standard error.

Front 32

Redirection Operators: >>

Back 32

Appends standard output to a file or creates the file if it does not currently exist.

Front 33

Redirection Operators: >

Back 33

Creates a new file or overwrites an existing file for standard output.

Front 34

Data Pipes: I

Back 34

A pipe will redirect the first program's standard output to the second program's standard input.

Front 35

tee

Back 35

Used to read from standard input and write to standard output and files (program | tee file.txt).

Front 36

xargs

Back 36

Build and execute command lines from standard input. Example: ls | grep test | xargs rm (will remove all files named test in the folder).

Front 37

cat

Back 37

Concatenate (combine) files.

Front 38

cat -n

Back 38

Number the lines of a file.

Front 39

join

Back 39

Used to join lines of two files on a common field.

Front 40

join -t {character}

Back 40

Use {character} as input and output field separator.

Front 41

join -1 {field}

Back 41

Join on this field of file 1.

Front 42

join -2 {field}

Back 42

Join on this field of file 2.

Front 43

join -i

Back 43

Ignore case when using the join command.

Front 44

paste

Back 44

Merge lines of files.

Front 45

expand

Back 45

Convert tabs to spaces.

Front 46

od

Back 46

Dump files in octal and other formats.

Front 47

sort

Back 47

Sort lines of text files. By default the sort command uses the first field. You can use -k option, separated by commas to change what field it sorts on.

Front 48

split

Back 48

Split a file into pieces. Example: split -l 2 file1.txt name (splits the file.txt file every two lines and places them in files starting with name (namea, nameb, namec) for number of lines by 2.

Front 49

tr

Back 49

Translate, squeeze, and/or delete characters from standard input, writing to standard output. Example: tr test blah < file.txt (replaces all the words 'test' to 'blah' in the file, and displays to standard output).

Front 50

unexpand

Back 50

Convert spaces to tabs.

Front 51

uniq

Back 51

Report or omit repeated lines.

Front 52

nl

Back 52

Print number of lines in a file

Front 53

head

Back 53

Output the first part of a file; echoes first 10 lines of the file by default.

Front 54

head -c

Back 54

Specify the number of bytes to view at the beginning of a file.

Front 55

head -n

Back 55

Specify the number of lines to view at the beginning of a file.

Front 56

tail

Back 56

Output the last part of a file; echoes the last 10 lines of the file by default.

Front 57

tail -c

Back 57

Specify the number of bytes to view at the end of a file.

Front 58

tail -n

Back 58

Specify the number of lines to view at the end of a file.

Front 59

less

Back 59

Used to page through files.

Front 60

cut

Back 60

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

Front 61

wc

Back 61

Word count of a selected file.

Front 62

sed

Back 62

A stream editor, used to perform basic text transformations on an input stream (a file or input from a pipeline).

While in some ways similar to an editor which permits scripted edits (such as ed), sed works by making only one pass over the input(s), and is consequently more efficient.

Front 63

$FCEDIT $EDITOR

Back 63

Environment variables that define the default text editors.