Bash brace expansion

Some examples of Bash's brace expansion.

The values inside the braces are repeated

echo a{b,c,d}e

abe ace ade

And you can embed braces within braces

echo a{b,c,d{e,f}}g

abg acg adeg adfg

Or it can be a sequence inside the braces

echo a{1..10}b

a1b a2b a3b a4b a5b a6b a7b a8b a9b a10b

Also includes an optional increment

echo a{1..10..2}

a1b a3b a5b a7b a9b

A simple real world example

mkdir -p james/{{logs,err}/{server1,server2},src,bin}

This makes the following directories:

james
james/logs
james/logs/server1
james/logs/server2
james/err
james/err/server1
james/err/server2
james/src
james/bin