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(1)/etc/profile: This file sets the environment information for each user of the system, and the file is executed when the user logs on for the first time. and collect the shell settings from the configuration file of the/ETC/PROFILE.D directory.
(2)/etc/environment: is the environment to set up the entire system , and/etc/profile is the setting of all users of the environment, the former is not related to the login user, the latter with the login user .
(3)/ETC/BASHRC: executes this file for each user running the bash Shell . When the bash shell is opened, the file is read.
(4) ~/.bash_profile: Each user can use this file to enter the shell information dedicated to their own use, when the user log on, the file is only executed once ! By default, he sets some environment variables to execute the user's. bashrc file.
(5) ~/.BASHRC: This file contains bash information dedicated to your bash shell, which is read when you log in and every time you open a new shell .
Linux environment variable file environment, profile, BASHRC meaning