沙盒

These definitions are used throughout the remainder of this manual.

这些定义将在本手册的其余部分使用到。

POSIX（可移植操作系统接口）

A family of open system standards based on Unix. Bash is primarily concerned with the Shell and Utilities portion of the POSIX 1003.1 standard.

基于Unix家族的一个开放系统标准。Bash主要关心POSIX 1003.1标准的Shell以及工具部分。

blank

A space or tab character.

一个空格（space）或制表符（tab）。

builtin（内建/嵌入）

A command that is implemented internally by the shell itself, rather than by an executable program somewhere in the file system.

一个由shell自己内部实现的的命令，它不是一个存储于文件系统中的可执行程序。

control operator（控制操作符）

A token that performs a control function. It is a newline or one of the following: ‘||’, ‘&&’, ‘&’, ‘;’, ‘;;’, ‘|’, ‘|&’, ‘(’, or ‘)’.

一个记号并执行一个控制功能。它是一个换行符或以下东东：‘||’, ‘&&’, ‘&’, ‘;’, ‘;;’, ‘|’, ‘|&’, ‘(’, or ‘)’。

exit status（退出状态）

The value returned by a command to its caller. The value is restricted to eight bits, so the maximum value is 255.

由命令返回该值到它的调用者。此值限于一个8比特值，所以它的最大值是255。

field（字段）

A unit of text that is the result of one of the shell expansions. After expansion, when executing a command, the resulting fields are used as the command name and arguments.

一个文本单位是该shell扩展的结果。扩展之后，当执行一个命令时，这个结果字段被用作命令名或参数。

filename

A string of characters used to identify a file.

由字符组成的字符串用于识别一个文件。

job（作业）

A set of processes comprising a pipeline, and any processes descended from it, that are all in the same process group.

由一组操作组成的操作流水，它的任何后裔操作均属于同一个操作组。

job control（作业控制）

A mechanism by which users can selectively stop (suspend) and restart (resume) execution of processes.

一套机制，用户可以选择性地停止和重启操作的执行。

metacharacter（元字符）

A character that, when unquoted, separates words. A metacharacter is a blank or one of the following characters: ‘|’, ‘&’, ‘;’, ‘(’, ‘)’, ‘<’, or ‘>’.

name

A word consisting solely of letters, numbers, and underscores, and beginning with a letter or underscore. Names are used as shell variable and function names. Also referred to as an identifier.

operator

A control operator or a redirection operator. See Redirections, for a list of redirection operators. Operators contain at least one unquoted metacharacter.

process group

A collection of related processes each having the same process group ID.

process group ID

A unique identifier that represents a process group during its lifetime.

reserved word

A word that has a special meaning to the shell. Most reserved words introduce shell flow control constructs, such as for and while.

return status

A synonym for exit status.

signal

A mechanism by which a process may be notified by the kernel of an event occurring in the system.

special builtin

A shell builtin command that has been classified as special by the POSIX standard.

token

A sequence of characters considered a single unit by the shell. It is either a word or an operator.

word

A sequence of characters treated as a unit by the shell. Words may not include unquoted metacharacters.