Explaining Brace Expansion in Bash
The aim of this page📝 is to delve into brace expansion in bash, exploring its history, functionality, and usage in various commands.
1 min readFeb 22, 2024
History of Brace Expansion
- Brace expansion was introduced in the Bourne Shell and later adopted by Bash.
- It allows for generating arbitrary strings based on patterns without external commands.
Functionality of Brace Expansion
- Brace expansion is a shell feature that generates multiple strings from a specified pattern enclosed in curly braces
{}. - It is not the same as globbing but is useful for creating lists of strings efficiently.
Usage of Brace Expansion
- Generating sequences of strings:
echo {1..5}
# 1 2 3 4 5- Creating combinations/cartesian product of strings:
echo {apples,bananas,oranges}_{ripe,unripe}.jpg
# apples_ripe.jpg apples_unripe.jpg bananas_ripe.jpg bananas_unripe.jpg oranges_ripe.jpg oranges_unripe.jpg- Enumerating options:
cp file{a,b,c}.txt destination/Benefits of Brace Expansion
- Provides a concise way to generate multiple strings without the need for loops or external commands.
- Useful for tasks like file copying, string manipulation, and generating sequences.
