Substring Extraction

In this page:

Substring Extraction

Substring Extraction

${variable:start:length} extracts a portion of a string starting at a given index (0-based) for a given number of characters. Omitting length extracts everything from start to the end. This is Bash's built-in equivalent of a substring function found in other languages.

Note: A negative start, like ${var: -3}, extracts from the end of the string (note the required space before the minus).

Example: Substring Extraction

bash

#!/bin/bash
text="Hello, Bash World!"
echo "${text:0:5}"
echo "${text:7:4}"
echo "${text:7}"

🔒

Chapter Quiz — Complete all 11 topics to unlock

0/11 topics done

Complete these topics first:

String Length
Defining and Calling Functions
Substring Extraction
Function Parameters
String Replacement
Return Values and Exit Codes
Local Variables and Scope
String Comparison
Recursion
grep with Strings
Sourcing Files to Share Functions

← Previous Lesson Defining and Calling Functions Next Lesson → Function Parameters

Substring Extraction

Substring Extraction

Chapter Quiz — Complete all 11 topics to unlock

Login to run this code