
bash - What are the special dollar sign shell variables ... - Stack ...
Sep 14, 2012 · In Bash, there appear to be several variables which hold special, consistently-meaning values. For instance, ./myprogram &; echo $! will return the PID of the process …
What does $# mean in bash? - Ask Ubuntu
Jul 25, 2017 · Furthermore, when you use bash -c, behavior is different than if you run an executable shell script, because in the latter case the argument with index 0 is the shell …
bash - What is the purpose of "&&" in a shell command? - Stack …
Oct 27, 2021 · Furthermore, you also have || which is the logical or, and also ; which is just a separator which doesn't care what happend to the command before.
bash - Shell equality operators (=, ==, -eq) - Stack Overflow
If not quoted, it is a pattern match! (From the Bash man page: "Any part of the pattern may be quoted to force it to be matched as a string."). Here in Bash, the two statements yielding "yes" …
bash - What does <<< mean? - Unix & Linux Stack Exchange
Take a look at the Bash man page. This notation is part of what's called a here documents & here strings. It allows you the ability to generate multi-line data input as one continuous string. The …
Bash test: what does "=~" do? - Unix & Linux Stack Exchange
Jan 27, 2017 · I realize you said “read the bash man pages” but at first, I thought you meant read the man pages within bash. At any rate, man bash returns a huge file, which is 4139 lines (72 …
bash - What does $ ( ... ) mean in the shell? - Unix & Linux Stack …
Sep 3, 2017 · For understanding bash code it is usually very helpful to set the -x option: set -x # within a script / function or when calling a script: bash -vx ./script.sh With loops this is a little …
bash - Difference between >> and - Unix & Linux Stack Exchange
In general, in bash and other shells, you escape special characters using \. So, when you use echo foo >\> what you are saying is "redirect to a file called > ", but that is because you are …
What's the difference between <<, <<< and < < in bash?
Sep 27, 2015 · What's the difference between <<, <<< and < < in bash?Here document << is known as here-document structure. You let the program know what will be the ending text, and …
What's the difference between [ and [[ in Bash? - Stack Overflow
Make sure you have the #!/bin/bash shebang line for your script if you use double brackets. See also Bash FAQ - "What is the difference between test, [ and [ [ ?" Bash Practices - Bash Tests …