====== Grouping commands ====== ===== Synopsis ===== { ; } { } ===== Description ===== The [[syntax:basicgrammar#lists|list]] '''' is simply executed in the **current** shell environment. The list must be terminated with a **newline** or **semicolon**. For parsing reasons, the curly braces must be separated from '''' by a **semicolon** and **blanks** if they're in the same line! ((Actually any properly terminated compound command will work without extra separator (also in some other shells), **example**: ''{ while sleep 1; do echo ZzZzzZ; done }'' is valid. But this is not documented, infact the documentation explicitly says that a semicolon or a newline must separate the enclosed list. -- thanks ''geirha'' at Freenode))((The main reason is the fact that in shell grammar, the curly braces are not control operators but reserved words -- TheBonsai)) This is known as a **group command**. The return status is the [[scripting:basics#exit_codes|exit status (exit code)]] of the list. The input and output **filedescriptors** are cumulative: { echo "PASSWD follows" cat /etc/passwd echo echo "GROUPS follows" cat /etc/group } >output.txt This compound command also usually is the body of a [[syntax:basicgrammar#shell_function_definitions | function definition]], though not the only compound command that's valid there: print_help() { echo "Options:" echo "-h This help text" echo "-f FILE Use config file FILE" echo "-u USER Run as user USER" } ===== Examples ===== ==== A Try-Catch block ==== try_catch() { { # Try-block: eval "$@" } || { # Catch-block: echo "An error occurred" return -1 } } ===== Portability considerations ===== ===== See also ===== * [[syntax:ccmd:grouping_subshell | grouping commands in a subshell]]