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 - What is the purpose of "&&" in a shell command? - Stack …
Dec 22, 2010 · $ 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 …
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 $@
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 …
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 …
What do the -n and -a options do in a bash if statement?
What are primaries? I call them "switches", but the bash documentation that you linked to refers to the same thing as "primaries" (probably because this is a common term used when discussing …
How to compare strings in Bash - Stack Overflow
Feb 10, 2010 · How do I compare a variable to a string (and do something if they match)?
How do I iterate over a range of numbers defined by variables in …
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?
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 …
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.