... In most cases on a Linux system this will be bash . It is bash 's job to read your commands and see that they are acted on. ... This looks at all the files in my home directory whose names start with sh-utils-1.16 and end with .patch . ... The file /etc/profile controls the system-wide behaviour of bash. ... Once bash has read the system-wide configuration file, it looks for your personal configuration file. It checks in your home directory for .bash_profile , .bash_login and .profile . ...