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.

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

26 DFómh 2023 · I have a script that parses a rudimentary .env file and exports its contents as environment variables, before taking further action: set -eu test -f .env && load_dotenv …

8 Beal 2012 · 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 …

2 Lún 2025 · When it comes to shell scripts it's difficult to support both short options and long options. I usually pick one or the other and use getopt or getopts as appropriate.

30 Iúil 2025 · This [escaping a colon in PATH on UNIX] is impossible according to the POSIX standard. This is not a function of a specific shell, PATH handling is done within the execvp …

Difference between Login Shell and Non-Login Shell? I have been looking at /etc/profile and /etc/bash.bashrc to see how they are run, and notice that some are executed by non-login …

I have a file, f1.txt: ID Name 1 a 2 b 3 g 6 f The number of spaces is not fixed. What is the best way to replace all the white spaces with one space using only tr? ...

What can you do with the eval command? Why is it useful? Is it some kind of a built-in function in bash? There is no man page for it..

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