Korn Shell: Unix and Linux Programming Manual, Third Edition, The

Environment

The environment (see environ(7)) is a list of name-value pairs that is passed to an executed program in the same way as a normal argument list. The names must be identifiers and the values are character strings. The shell interacts with the environment in several ways. On invocation, the shell scans the environment and creates a variable for each name found, giving it the corresponding value and attributes and marking it export. Executed commands inherit the environment. If the user modifies the values of these variables or creates new ones, using the export or typeset-x commands, they become part of the environment. The environment seen by any executed command is thus composed of any name-value pairs originally inherited by the ...