How to assign variables in bash? Discover simple steps for scripting beginners to start coding.

Variable assignment is fundamental in Bash scripting. Here are key methods and rules:

Basic Variable Assignment

Use the operator with no spaces:

name="value"

count=5

Accessing Variables

Prefix the variable name with :

echo $name   # Outputs 'value'
result=$((count  2))

Key Rules

• No spaces around : var=42 works; var = 42 fails
• Variable names are case-sensitive: $Var and $var differ
• Use uppercase by convention: API_KEY="secret"
• Names can contain letters, numbers, underscores: user_1="Alice"

Quoting Values

Use double quotes for multi-word values:

message="Hello World"
path="/home/user/docs"

Prevent unexpected word splitting with special characters using quotes.

Assigning Command Output

Capture command output with or backticks:

current_date=$(date)

file_list=`ls /dir`

Read-only Variables

Declare constants with readonly:

readonly MAX_CONNECTIONS=10

Local Variables in Functions

Limit scope with local:

myfunc() {

local func_var="This exists only in myfunc"

Advanced Assignment Techniques

• Default value: ${var:-default}
• Assignment with default: ${var:=backup_value}
• Declare integer: declare -i num=5
• Associative arrays: declare -A dict=(["key"]="value")

Practice these patterns to build robust scripts while avoiding common syntax pitfalls.