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 which …

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 whenever that …

Dec 22, 2010 · 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.

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" are pattern …

Oct 18, 2013 · 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; …

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 command used to invoke it.

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 less helpful. But …

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 placing $ means passing...

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 escaping the …

Oct 4, 2008 · Related discusions: bash for loop: a range of numbers and unix.stackexchange.com - In bash, is it possible to use an integer variable in the loop control of a for loop?