brace expansion - How to store curly brackets in a Bash variable

Question

I am trying to write a bash script. I am not sure why in my script:

ls {*.xml,*.txt} 

works okay, but

name="{*.xml,*.txt}"
ls $name

doesn't work. I get

ls: cannot access {*.xml,*.txt}: No such file or directory

Answer 1

The expression

ls {*.xml,*.txt}

results in Brace expansion and shell passes the expansion (if any) to ls as arguments. Setting shopt -s nullglob makes this expression evaluate to nothing when there are no matching files.

Double quoting the string suppresses the expansion and shell stores the literal contents in your variable name (not sure if that is what you wanted). When you invoke ls with $name as the argument, shell does the variable expansion but no brace expansion is done.

As @Cyrus has mentioned, eval ls $name will force brace expansion and you get the same result as that of ls {*.xml,*.txt}.