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 …

Oct 27, 2021 · $ command one && command two the intent is to execute the command that follows the && only if the first command is successful. This is idiomatic of Posix shells, and not …

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 …

Oct 18, 2013 · What is the operator =~ called? I'm not sure it has a name. The bash documentation just calls it the =~ operator. Is it only used to compare the right side against the …

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 …

529 = and == are for string comparisons -eq is for numeric comparisons -eq is in the same family as -lt, -le, -gt, -ge, and -ne == is specific to bash (not present in sh (Bourne shell), ...). Using …

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 …

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 …

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 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 …