Shell - "Shell" is a program, which facilitates the interaction between the user and the operating system (kernel). There are many shell implementations available, like sh, Bash, C shell, Z shell, etc.
I understand the basic difference between an interactive shell and a non-interactive shell. But what exactly differentiates a login shell from a non-login shell? Can you give examples for uses of...
I often come across $?, $0, $1, $2, etc in shell scripting. I know that $? returns the exit status of the last command: echo "this will return 0" echo $? But what do the others do? What ...
The shell is the program which actually processes commands and returns output. Most shells also manage foreground and background processes, command history and command line editing.
docker debug <container or image> It allows you to get a shell (bash/fish/zsh) into any container. It also works for stopped containers and images. Essentially it's a replacement of docker exec -it <container> sh but with more features and less constraints (eg the debug shell has an install command to add further tools).
A bashism is a shell feature which is only supported in bash and certain other more advanced shells. It will not work under busybox sh or dash (which is /bin/sh on a lot of distros), or certain other shells like the /bin/sh provided on FreeBSD.
