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How do you know which bash I am using?
To test the above, say bash is the default shell, try echo $SHELL , and then in the same terminal, get into some other shell (KornShell (ksh) for example) and try $SHELL . You will see the result as bash in both cases. To get the name of the current shell, Use cat /proc/$$/cmdline .
What is difference between Dash and bash?
Bash continues to be used as the default interactive/login shell for users, but Dash is the one at /bin/sh and the one which is executed for system scripts such as init scripts. Dash is very fast, but also is very closely POSIX-compatible – a standard that is aligned closely with the Bourne shell.
Can Dash run Bash?
Dash (Debian Almquist shell) is a modern POSIX-compliant implementation of /bin/sh (sh, Bourne shell). Dash is not Bash compatible, but Bash tries to be mostly compatible with POSIX, and thus Dash. Dash shines in: Thus, Dash has a much smaller attack surface, while still having many eyes on its code.
What is the point of bash being linked to dash?
Sure, shiny features of bash are cool to use for us users, but when it comes to running thing in environment where you have to manage several different servers/systems – having POSIX compliant shell makes whole lot of difference. Especially, if you’re a new sysadmin and inherited environment with many scripts.
When does Bash not have the prompt set?
When an interactive shell that is not a login shell is started, bash reads and executes commands from ~/.bashrc, if that file exists. Not having your prompt set can occur in two different contexts then, login shells and non-login shells.
Why is Bash the default shell in Ubuntu?
The major reason to switch the default shell was efficiency. bash is an excellent full-featured shell appropriate for interactive use; indeed, it is still the default login shell. However, it is rather large and slow to start up and operate by comparison with dash. A large number of shell instances are started as part of the Ubuntu boot process.
Why do we use Bash in / bin / sh?
GNU wanted a Bourne-like shell that was under the GPL, so that’s why they chose Bash for their /bin/sh, instead of Bourne, which was not GPL-licensed. Modern Linux distros inherited this decision to the point that it became a defacto standard for /bin/sh to be Bash.