O traço principal indica um shell de login, de man bash
:
A login shell is one whose first character of argument zero is a
-
, or one started with the--login
option.When bash is invoked as an interactive login shell, or as a non-interactive shell with the
--login
option, it first reads and executes commands from the file/etc/profile
, if that file exists. After reading that file, it looks for~/.bash_profile
,~/.bash_login
, and~/.profile
, in that order, and reads and executes commands from the first one that exists and is readable. The--noprofile
option may be used when the shell is started to inhibit this behavior.When a login shell exits, bash reads and executes commands from the file
~/.bash_logout
, if it exists.
bash
e /bin/bash
são os mesmos, eles foram chamados de maneira diferente (o primeiro não foi chamado usando o caminho completo).