Terminal uses an interactive non-login shell
SSH uses an interactive login shell
Running a script uses non-interactive non-login shell
# i: Interative Shell
# l: Login Shell (Not always present)
echo $-
# -: Login Shell (Not always present)
echo $0Interactive Login Shell
The user is expected to provide the input (interact)
Used when a new session is started using console or SSH
The input and output are both connected to the terminal and will be visible to user
This type of shell uses the .zprofile and .zshenv file
Interactive Non-Login Shell
The user is expected to provide the input (interact)
Used when a new terminal is opened or a new shell is spawned
This type of shell uses the .zshrc and .zshenv file
Non-Interactive Login Shell
Very rarely used
It is non-interactive (no user input) and loads config to setup environment
Can be used by automated scripts
The output of non-interactive shells are not normally shown to user
This type of shell uses the .zprofile and .zshenv file
Non-Interactive Non-Login Shell
This type of shell is commonly used to run automated scripts (cron, -c)
User cannot interact with the shell and no config to setup environment is used
The output of non-interactive shells are not normally shown to user
This type of shell uses the .zshenv file