SHELL：交互式shell和非交互式shell、登录shell和非登录shell的区别

[root@test ~]# man bash
	-i
	    If the -i option is present, the shell is interactive.
	--noprofile
	    Do not read either the system-wide startup file /etc/profile or any of the personal initialization files ~/.bash_profile, ~/.bash_login, or ~/.profile.  By default, bash reads these files when  it  is  invoked  as  a login shell (see INVOCATION below).

http://smilejay.com/2012/10/interactive-shell-login-shell/