Brace expansion Bash (Unix shell)

users should not use brace expansions in portable shell scripts, because bourne shell not produce same output.

when brace expansion combined wildcards, braces expanded first, , resulting wildcards substituted normally. hence, listing of jpeg , png images in current directory obtained using:

in addition alternation, brace expansion can used sequential ranges between 2 integers or characters separated double dots. newer versions of bash allow third integer specify increment.

when brace expansion combined variable expansion variable expansion performed after brace expansion, in cases may necessitate use of eval built-in, thus: