Open links in new tab
  1. 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 …

  2. bash - What is the purpose of "&&" in a shell command? - Stack …

    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 …

  3. bash - Shell equality operators (=, ==, -eq) - Stack Overflow

    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" …

  4. How do I execute a bash script in Terminal? - Stack Overflow

    Mar 9, 2018 · I have a bash script like: #!/bin/bash echo Hello world! How do I execute this in Terminal?

  5. Meaning of $? (dollar question mark) in shell scripts

    Aug 1, 2019 · 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 …

  6. What does $# mean in bash? - Ask Ubuntu

    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 …

  7. 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 …

  8. Bash test: what does "=~" do? - Unix & Linux Stack Exchange

    Jan 27, 2017 · I realize you said “read the bash man pages” but at first, I thought you meant read the man pages within bash. At any rate, man bash returns a huge file, which is 4139 lines (72 …

  9. bash - Difference between >> and - Unix & Linux Stack Exchange

    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 …

  10. 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 …