-bash: /etc/profile: Permission denied in Terminal

Select the text below, ctrl-click it & choose Services - Reveal in Finder

/etc/profile

A Finder window should open, with that file selected. Press Command I or File menu - Get Info

If the Sharing & Permissions section includes everyone : No Access, then click the padlock icon, enter an Admin name & password when prompted, then change it to everyone : Read Only.

The permissions on /etc/profile are read-only for a reason. You don't change that file, or its permissions.

What is in your Bash startup files [.bash_profile, .bash_login, .bashrc, or .profile] in your home directory that is attempting to write to /etc/profile? Nothing should. The Terminal Preferences : Shell tab : Startup : Run command should be unchecked, and so should run inside shell. Bash is the default shell without these settings.

To debug the problem, you may have to create a new folder in your home directory, and move these individual files into it, quit Terminal, and launch it again.

-bash-3.2$ mkdir ~/old_dotfiles

-bash-3.2$ mv ~/.bash_* ~/old_dotfiles; mv ~/.profile ~/old_dotfiles

To set your Terminal prompt, put the following in your new ~/.bash_profile:

MyHost="$(networksetup -getcomputername)"

export PS1='$MyHost: \w\$ '

-bash-3.2$ source ~/.bash_profile

computername: ~$

I use networksetup above so that my computername always appears in the prompt, instead of some remote DNS name when I use VPN. Here is a reference to other PS1 prompt switches.