The particular initialization files responsible for your system's configuration depend on which shell the system administrator has specified as your default shell when your system was first installed. The Bourne shell is the default shell for the Solaris operating environment, but you can also use the C shell or Korn shell. Each of these shells has its own initialization file (or files).
$ echo $SHELL /bin/sh
Review the output of the command to determine your default shell.
Refer to the following list to identify your default shell.
Regardless of the shell you are using, when you first log in your system generally runs the system profile file, /etc/profile. This file is generally owned by the system administrator and is readable (but not writable) by all users.
After your system executes the system profile, it runs the user profile. The user profile is one (or more) initialization files that define your working environment. For example, if you're in the CDE environment your system checks this file (or set of files) each time you start a new terminal or window.
Depending on which shell is set up as your default, your user profile can be one of the following:
.profile (for the Bourne and Korn shells)
.bash_profile (for the Bourne Again shell)
.login and .cshrc (for the C shell)
.tcshrc and .cshrc (for the TC shell)
.zlogin and .zshrc (for the Z shell)