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 …

Feb 20, 2011 · When going through one shell script, I saw the term "$?". What is the significance of this term?

Oct 27, 2021 · The shell will try to create directory test and then, only if it was successful will try create file inside it. So you may interrupt a sequence of steps if one of them failed.

BTW, in bash a semi-colon is a statement separator, not a statement terminator, which is a new-line. So if you only have one statement on a line then the ; at end-of-line are superfluous. Not …

I want to redirect both standard output and standard error of a process to a single file. How do I do that in Bash?

What does $# mean in shell? I have code such as if [ $# -eq 0 ] then I want to understand what $# means, but Google search is very bad for searching these kinds of things.

Nov 15, 2010 · 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 …

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 is the Linux command to check the server OS and its version? I am connected to the server using shell.

Aug 30, 2010 · How do I know if a variable is set in Bash? For example, how do I check if the user gave the first parameter to a function? function a { # if $1 is set ? }