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====== Grouping commands ======
===== Synopsis ===== <code>{ <LIST>; }</code>
<code> { <LIST> } </code>
===== Description =====
The list ''<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 ''<LIST>'' 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 exit status (exit code) of the list.
The input and output filedescriptors are cumulative: <code> { echo "PASSWD follows" cat /etc/passwd echo echo "GROUPS follows" cat /etc/group } >output.txt </code>
This compound command also usually is the body of a function definition, though not the only compound command that's valid there: <code> print_help() { echo "Options:" echo "-h This help text" echo "-f FILE Use config file FILE" echo "-u USER Run as user USER" } </code>
===== Examples ===== ==== A Try-Catch block ====
try_catch() {
{ # Try-block:
eval "$@"
} ||
{ # Catch-block:
echo "An error occurred"
return -1
}
}
===== Portability considerations =====
===== See also =====