rc 命令

常用示例

说明

rc is the Plan 9 command interpreter, offering a cleaner alternative to the Bourne shell. Originally designed for Plan 9 from Bell Labs, it has been ported to Unix systems and provides a simpler, more consistent syntax. Unlike the Bourne shell's string variables, rc provides list-valued variables (arrays of strings) as a fundamental type. This eliminates many quoting problems and makes argument handling more natural. Rc uses C-like syntax for control structures: if, while, for, switch, and fn for function definitions. The syntax is defined by a formal grammar (implemented with yacc), making it unambiguous and predictable. Pipes, redirections, and command substitution work similarly to other shells. Background execution uses &, and command grouping uses {} instead of subshells.

参数

-c _command_

Execute the given command string and exit

-e

Exit if any command returns non-zero status

-i

Run interactively (read commands from terminal)

-l

Behave as a login shell (read profile)

-n

Do not read the personal profile ($home/lib/profile)

-v

Echo input to standard error as it is read

-x

Print commands and arguments as they are executed