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 …

command-line - what is the purpose of &&? In shell, when you see $ command one && command two the intent is to execute the command that follows the && only if the first command is …

The =~ operator is a regular expression match operator. This operator is inspired by Perl's use of the same operator for regular expression matching. The [[ ]] is treated specially by bash; …

Oct 10, 2010 · I reckon that the handle $@ in a shell script is an array of all arguments given to the script. Is this true? I ask because I normally use search engines to gather information, but I …

It depends on the Test Construct around the operator. Your options are double parentheses, double brackets, single brackets, or test. If you use ((…)), you are testing arithmetic equality …

Apr 3, 2012 · What does a dollar sign followed by an at-sign (@) mean in a shell script? For example: umbrella_corp_options $@

Aug 1, 2019 · This is the exit status of the last executed command. For example the command true always returns a status of 0 and false always returns a status of 1: true echo $? # echoes …

I have two questions and could use some help understanding them. What is the difference between ${} and $()? I understand that () means running command in separate shell and …

Jun 3, 2012 · Quoting from man bash: -c string If the -c option is present, then commands are read from string. If there are arguments after the string, they are assigned to the positional …

A curated list of delightful Bash scripts and resources. In addition to this list, you should read the list awesome-shell. It is a curated list of awesome command-line frameworks, toolkits, guides …