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declare

file managementLinux/Unix
The declare command is one of the most frequently used commands in Linux/Unix-like operating systems. declare Sample fallback description for declare
See ExamplesView Syntax

Quick Reference

Command Name:

declare

Category:

file management

Platform:

Linux/Unix

Basic Usage:

declare -i number=10

Common Use Cases

  • 1

    Variable typing

    Declare variables with specific attributes and constraints in Bash

  • 2

    Array creation

    Define and manage indexed and associative arrays in shell scripts

  • 3

    Function parameter handling

    Create variables with specific behaviors for function inputs

  • 4

    Script debugging

    Enable variable tracing and error detection in complex scripts

Syntax

declare [OPTION]... [FILE]...

Options

Option Description
-l Use a long listing format
-a Show hidden entries starting with .
-h Human-readable sizes
-R List subdirectories recursively

Examples

How to Use These Examples

The examples below show common ways to use the declare command. Try them in your terminal to see the results. You can copy any example by clicking on the code block.

Basic Examples:

ls
List files in the current directory.
ls -l
List files in long format with details.
ls -a
List all files including hidden ones.

Advanced Examples:

ls -lah Detailed list with human-readable sizes. ls -R List directories recursively.

Try It Yourself

Practice makes perfect! The best way to learn is by trying these examples on your own system with real files.

Understanding Syntax

Pay attention to the syntax coloring: commands, options, and file paths are highlighted differently.

Notes

These are sample notes for the declare command.

Tips & Tricks

1

Use the -a option to declare an array variable

2

Use the -A option to declare an associative array variable

3

Use the -i option to declare an integer variable

4

Use the -r option to declare a readonly variable

5

Use the -x option to declare an exported variable

Common Use Cases

Variable typing

Declare variables with specific attributes and constraints in Bash

Array creation

Define and manage indexed and associative arrays in shell scripts

Function parameter handling

Create variables with specific behaviors for function inputs

Script debugging

Enable variable tracing and error detection in complex scripts

Variable scope control

Control variable visibility and exportability to child processes

Related Commands

These commands are frequently used alongside declare or serve similar purposes:

typeset
export
local
readonly
set
unset
env
printenv
Explore All Commands

Use Cases

1

Variable typing

Declare variables with specific attributes and constraints in Bash

2

Array creation

Define and manage indexed and associative arrays in shell scripts

3

Function parameter handling

Create variables with specific behaviors for function inputs

4

Script debugging

Enable variable tracing and error detection in complex scripts

5

Variable scope control

Control variable visibility and exportability to child processes

Learn By Doing

The best way to learn Linux commands is by practicing. Try out these examples in your terminal to build muscle memory and understand how the declare command works in different scenarios.

See ExamplesTry Lab Exercises
$ declare
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