환경변수,environment_variable

환경,environment
변수,variable
TODO mv from 변수,variable...!!

rel
셸,shell

Sub:
PATH - see 경로,path?action=highlight&value=변수명
LD_LIBRARY_PATH - Srch:LD_LIBRARY_PATH .... for 라이브러리,library
POSIXLY_CORRECT
{
(command line에서 option을 줄 때) 이게 set이면, option들은 operand앞에 있어야만 한다고.
QQQ set이라는건 =1로 정의인가, 아님 defined인가?
QQQ 이 옵션의 용도가 무엇인지?

Normally options and operands can appear in any order, and programs
act as if all the options appear before any operands. For example,
‘sort -r passwd -t :’ acts like ‘sort -r -t : passwd’, since ‘:’ is an
option-argument of ‘-t’. However, if the ‘POSIXLY_CORRECT’ environment
variable is set, options must appear before operands, unless otherwise
specified for a particular command.
(from GNU info > coreutils > 2 Common options)
}