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  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 which …

  2. 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 command used to invoke it.

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

    Oct 27, 2021 · 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.

  4. What does 'set -e' mean in a Bash script? - Stack Overflow

    By default, Bash does not do this. This default behavior is exactly what you want if you are using Bash on the command line you don't want a typo to log you out! But in a script, you really want the …

  5. 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" are pattern …

  6. 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 to the exit status …

  7. 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 pages) long.

  8. What does the -e do in a bash shebang? - Unix & Linux Stack Exchange

    All the bash command line switches are documented in man bash. -e Exit immediately if a pipeline (which may consist of a single simple command), a subshell command enclosed in parentheses, or …

  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 escaping the …

  10. bash if -a vs -e option - Stack Overflow

    Use -e . For single ' [', the bash builtin behaves the same as the test bash builtin, which behaves the same as /usr/bin/[ and /usr/bin/test (the one is a symlink to the other). Note the effect of -a depends …