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 …
bash - Shell equality operators (=, ==, -eq) - Stack Overflow
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 …
shell - Bash regex =~ operator - Stack Overflow
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 …
linux - What does $@ mean in a shell script? - Stack Overflow
Apr 3, 2012 · What does a dollar sign followed by an at-sign (@) mean in a shell script? For example: umbrella_corp_options $@
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 …
An "and" operator for an "if" statement in Bash - Stack Overflow
Modern shells such as Bash and Zsh have inherited this construct from Ksh, but it is not part of the POSIX specification. If you're in an environment where you have to be strictly POSIX …
How do AND and OR operators work in Bash? - Stack Overflow
8 In bash, && and || have equal precendence and associate to the left. See Section 3.2.3 in the manual for details. So, your example is parsed as $ (echo this || echo that) && echo other And …
bash - Precedence of the shell logical operators &&, || - Unix
From the bash manpage (edited)... Lists A list is a sequence of one or more pipelines separated by one of the operators ;, &, &&, or ││, and optionally terminated by one of ;, &, or . Of these …
bash - Difference between 'if -e' and 'if -f' - Stack Overflow
Apr 18, 2012 · 59 $ man bash -e file True if file exists. -f file True if file exists and is a regular file. A regular file is something that isn't a directory, symlink, socket, device, etc.
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 …