pure-bash-bible

Table of Contents

FOREWORD

STRINGS

Trim leading and trailing white-space from string

Trim all white-space from string and truncate spaces

Use regex on a string

Split a string on a delimiter

Change a string to lowercase

Change a string to uppercase

Reverse a string case

Trim quotes from a string

Strip all instances of pattern from string

Strip first occurrence of pattern from string

Strip pattern from start of string

Strip pattern from end of string

Percent-encode a string

Decode a percent-encoded string

Check if string contains a sub-string

Check if string starts with sub-string

Check if string ends with sub-string

ARRAYS

Reverse an array

Remove duplicate array elements

Random array element

Cycle through an array

Toggle between two values

LOOPS

Loop over a range of numbers

Loop over a variable range of numbers

Loop over an array

Loop over an array with an index

Loop over the contents of a file

Loop over files and directories

FILE HANDLING

Read a file to a string

Read a file to an array (by line)

Get the first N lines of a file

Get the last N lines of a file

Get the number of lines in a file

Count files or directories in directory

Create an empty file

Extract lines between two markers

FILE PATHS

Get the directory name of a file path

Get the base-name of a file path

VARIABLES

Assign and access a variable using a variable

Name a variable based on another variable

ESCAPE SEQUENCES

Text Colors

Text Attributes

Cursor Movement

Erasing Text

PARAMETER EXPANSION

Indirection

Replacement

Length

Expansion

Case Modification

Default Value

BRACE EXPANSION

Ranges

String Lists

CONDITIONAL EXPRESSIONS

File Conditionals

File Comparisons

Variable Conditionals

Variable Comparisons

ARITHMETIC OPERATORS

Assignment

Arithmetic

Bitwise

Logical

Miscellaneous

ARITHMETIC

Simpler syntax to set variables

Ternary Tests

TRAPS

Do something on script exit

Ignore terminal interrupt (CTRL+C, SIGINT)

React to window resize

Do something before every command

Do something when a shell function or a sourced file finishes executing

PERFORMANCE

Disable Unicode

OBSOLETE SYNTAX

Shebang

Command Substitution

Function Declaration

INTERNAL VARIABLES

Get the location to the `bash` binary

Get the version of the current running `bash` process

Open the user's preferred text editor

Get the name of the current function

Get the host-name of the system

Get the architecture of the Operating System

Get the name of the Operating System / Kernel

Get the current working directory

Get the number of seconds the script has been running

Get a pseudorandom integer

INFORMATION ABOUT THE TERMINAL

Get the terminal size in lines and columns (from a script)

Get the terminal size in pixels

Get the current cursor position

CONVERSION

Convert a hex color to RGB

Convert an RGB color to hex

CODE GOLF

Shorter `for` loop syntax

Shorter infinite loops

Shorter function declaration

Shorter `if` syntax

Simpler `case` statement to set variable

OTHER

Use `read` as an alternative to the `sleep` command

Check if a program is in the user's PATH

Get the current date using `strftime`

Get the username of the current user

Generate a UUID V4

Progress bars

Get the list of functions in a script

Bypass shell aliases

Bypass shell functions

Run a command in the background

Capture the return value of a function without command substitution

AFTERWORD