bash - Shell equality operators (=, ==, -eq) - Stack Overflow
Shell equality operators (=, ==, -eq) Asked 12 years, 3 months ago Modified 3 years, 9 months ago Viewed 656k times

Difference between ${} and $() in a shell script - Super User
Difference between $ {} and $ () in a shell script Ask Question Asked 10 years, 8 months ago Modified 1 year, 1 month ago

regex - Meaning of "=~" operator in shell script - Stack Overflow
Meaning of "=~" operator in shell script [duplicate] Ask Question Asked 13 years, 6 months ago Modified 12 years, 7 months ago

What is the meaning of $? in a shell script? - Unix & Linux Stack Exchange
When going through one shell script, I saw the term "$?". What is the significance of this term?

What does $# mean in shell? - Unix & Linux Stack Exchange
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.

Meaning of $? (dollar question mark) in shell scripts
What does echo $? mean in shell programming? true echo $? # echoes 0 false echo $? # echoes 1 From the manual: (acessible by calling man bash in your shell) ? Expands to the exit status of the most recently executed foreground pipeline. By convention an exit status of 0 means success, and non-zero return status means failure. Learn more about exit statuses on wikipedia. There are other special ...

What is the $? (dollar question mark) variable in shell scripting?
I'm trying to learn shell scripting, and I need to understand someone else's code. What is the $? variable hold? I can't Google search the answer because they block punctuation characters.

What is the difference between $@ and $* in shell scripts?
In shell scripts, what is the difference between $@ and $*? Which one is the preferred way to get the script arguments? Are there differences between the different shell interpreters about this?

What are the special dollar sign shell variables? - Stack Overflow
$! is the PID of the most recent background command. $0 is the name of the shell or shell script. Most of the above can be found under Special Parameters in the Bash Reference Manual. Here are all the environment variables set by the shell. For a comprehensive index, please see the Reference Manual Variable Index.

      >> Live EBAY Auctions