# { > Multipurpose shell syntax. > More information: . - Isolate variable names: `echo ${HOME}work` - Brace expand sequences: `echo {1..3} {a..c}{dir1,dir2,dir3}` - Check if `variable` is set before returning text: `echo ${variable:+variable is set and contains $variable}` - Set default values in case `variable` is unset: `echo ${variable:-default}` - Return `variable` length in characters: `echo ${#variable}` - Return a string slice: `echo ${variable:3:7}` - Recursively expand a `variable`: `echo ${!variable}` - Group command output together: `{ {{command1; command2; ...}} } | {{another_command}}`