Index

Bash Unix Shell Scripting:
 

Index

This index / glossary / quick-reference lists many of the important topics covered in the text. Terms are arranged in approximate ASCII sorting order, modified as necessary for enhanced clarity.

Note that commands are indexed in .

* * *

^ (caret)

~ Tilde

= Equals sign

< Left angle bracket

> Right angle bracket

| , a device for passing the output of a command to another command or to the shell

||

- (dash)

; (semicolon)

: Colon

! , inverts of a test or command

? (question mark)

// , behavior of command toward

. (dot / period)

' ... ' (single quotes)

" ... " (double quotes)

,

() Parentheses

[ , test construct

[ ]Brackets

[[ ... ]] , extended test construct

$ , in a

$

$( ... ) , setting a variable with output of a command, using parentheses notation

` ... ` , using notation

$[ ... ] (deprecated)

${ ... } Variable manipulation / evaluation

$' ... ' , using escaped characters.

\ the character following

&

# , special symbol beginning a script comment

#! , special string starting a

* Asterisk

% Percent sign

+ Plus sign

* * *

Shell Variables

$_

$- , using

$!

$?

$@ All the positional parameters,

$* All the positional parameters,

$$ of the script

$# to a , or to the script itself

$0

$1

$9

of shell variables

* * * * * *

-a compound comparison test

Address database,

Advanced Bash Scripting Guide,

&&

, escaped, \< . . . \> word boundary in a

, using :

, detecting

ASCII

field-oriented text processing language

* * *

Backlight,

, used in

, example script

, external

, DOS

, calculator utility

utility

, creating

Brackets, [ ]

Brackets, curly, {}, used in

loop control command

in Bash

* * *

, concatentate file(s)

, : , equivalent to the Bash builtin

, linking commands or operations

builtin error-handling function ( of Bash)

, special purpose

Commenting out blocks of code

operators

loop control command

, scheduling daemon

, for handling variables

Curly brackets {}

* * *

, in UNIX-type OS

, calculator utility

, data duplicator command

, Bash interprets numbers as

builtin

directory

, utility for generating dialog boxes in a script

directory stack

, in restricted shells

keyword, begins execution of commands within a

keyword, terminates a loop

, converting to shell scripts

, UNIX equivalents of (table)

, "hidden" setup and configuration files

[[ ... ]] construct

(( ... )) arithmetic expansion/evaluation construct

" ... " weak quoting

, using

* * *

-e test

, Contraction of else and

Encrypting files, using

, keyword terminating case construct

, is-equal-to test

, algorithm for generating prime numbers

, special meanings of

(filesystem mount) file

(user account) file

, Effective user ID

, Combine and evaluate expression(s), with variable expansion

command, using in

Exit and Exit status

, to make available variables to

, Expression evaluator

* * *

, decomposes an integer into its prime factors

, returns unsuccessful (1)

, a group of characters that comprises an item of data

, Bash does not recognize

, a filter to wrap lines of text

a child process

* * *

Games and amusements

, external command for parsing script command-line arguments

, Bash builtin for parsing script command-line arguments

variable

, filename expansion

(Phi)

, greater-than or equal test

, greater-than test

, text markup and formatting language

, Groups user belongs to

, compression utility

* * *

, creating lookup keys in a table

, echo to stdout lines at the beginning of a text file

, gives usage summary of a Bash

, user's home directory

, system host name

* * *

, in rcs (Revision Control System)

test construct

, Internal field separator variable

, keyword preceding [list] in a for loop

, /etc/inittab

, i.e., code block

, test for

, packet filtering and firewall utility

* * *

, table

, Emit a sequence of integers. Equivalent to .

* * *

, terminate a process by

, terminate a process by name

in /etc/rc.d/init.d

* * *

shell option

, less-than or equal test

, setting and carrying out arithmetic operations on variables

, in a

, variable indicating the line number where it appears in a script

, file (using ln command)

(&&, ||, etc.)

, the ~/.bash_logout file

, mounting a file on a

Loopback devices

, less-than test

* * *

, macro processing language

, Machine type

, marker at the head of a file indicating the file type

, file containing the list of dependencies used by command

, manual page (lookup)

builtin, loads an array with a text file

script

, arithmetic remainder operator

, example script

* * *

-n test

, a temporary FIFO buffer

, netcat, a network toolkit for TCP and UDP ports

, not-equal-to test

, !, reverses the sense of a

, Network statistics

, a filter to number lines of text

, -C option to Bash to prevent overwriting of files

, !

, avoiding

* * *

-o compound comparison test

Obfuscation

, base-8 numbers

, octal dump

Previous working directory

encryption utility

Operator

, passed to shell or script on command line or by command

, ||

* * *

, a child process cannot variables to a

Parentheses

, the path (location of system binaries)

, a filename that incorporates the complete path of a given file.

, programming language

(Quackey script)

, Process ID, an identification number assigned to a running process.

, | , a device for passing the output of a command to another command or to the shell

Pointers

in shell scripting

, Portable Operating System Interface / UNIX

, process ID of parent process

, operator

lines at head of a file, script example

Prime numbers

, formatted print command

directory

(tab expansion)

Prompt

, as problem-solving method

, Current working directory

* * *

, a Perquackey-type anagramming game (script)

Question mark, ?

* * *

Random numbers

Raspberry Pi (single-board computer)

, set value of a variable from

library

Redirection

, Default value associated with command

, shell (or script) with certain commands disabled

, command that terminates a

* * *

of a variable, definition

, set at command line

, library of useful definitions and

, $PS2

, pattern-based programming language

, construct for menu building

, when keyword is on first line of

, Emit a sequence of integers. Equivalent to .

, Change value of internal script variables

, definition of

, script embedding a command or utility

, reassigning positional parameters

, shell level, depth to which the shell (or script) is nested

, change shell options

, a message sent to a process

Simulations

(' ... ') strong

, a communication node associated with an I/O port

Sorting

, execute a script or, within a script, import a file

Spam, dealing with

Stack

Standard Deviation,

, Bash

, example script

Strings

' ... '

for writing scripts

Substitute user, log on as a different user or as root

(set user id) file flag

* * *

Table lookup,

, echo to stdout lines at the (tail) end of a text file

, archiving utility

, redirect to a file output of command(s) partway through a

test command

Test operators

Timed input

for Bash scripts

, Timeout interval

, a symbol that may expand to a or command

, terminal-control command

, character translation filter

, specifying an action upon receipt of a

Trinary (ternary) operator, C-style, var>10?88:99

, returns successful (0)

builtin

* * *

, User ID number

, to remove an

, output system information

, encoding standard for representing letters and symbols

, filter to remove duplicate lines from a sorted file

, delete a shell variable

loop

until [ condition-is-true ]; do

* * *

Variables

* * *

, suspend script execution

" ... "

loop

while [ condition ]; do

, spaces, tabs, and newline characters

, information about logged on users

characters

Word splitting

, shell

* * *

, Filter for grouping arguments

* * *

* * *

-z

, a process that has terminated, but not yet been by its