环境变量

语句格式

string = ENVVAR/ 'variable'{,ASK|,SET,'value'}[,IFERR,label:]

描述

提供对环境变量。平移，设置或创建指定的环境变量。做一个查询时的环境变量必须已经存在。当设置环境变量，一个新的，如果不存在创建;否则，该变量的值被修改。在没有发生错误的所有情况下，该命令将返回指定的环境变量中一个串的形式的最新翻译。当发生错误时，给出一个错误信息或者IFERR是支链上，并没有什么被返回

参数

Parameter

Description

variable

A string representing the environment variable to access. This string is case sensitive in the UNIX operating system.

ASK

Minor word that specifies the translation of an environment variable.

SET

Minor word that specifies the creation or setting of an environment variable.

value

A string representing the value of the environment variable to use in the set operation.

IFERR,label:

Specifies a label to which program execution jumps if an error occurs.

Parameter	Description
variable	A string representing the environment variable to access. This string is case sensitive in the UNIX operating system.
ASK	Minor word that specifies the translation of an environment variable.
SET	Minor word that specifies the creation or setting of an environment variable.
value	A string representing the value of the environment variable to use in the set operation.
IFERR,label:	Specifies a label to which program execution jumps if an error occurs.