Getting started with Bash Using "trap" to react to signals and system events Listing Files Aliasing Jobs and Processes Redirection Control Structures Using cat Arrays Functions Bash Parameter Expansion Sourcing Find Here documents and here strings Quoting Conditional Expressions Scripting with Parameters Bash history substitutions Math Scoping Process substitution Programmable completion Customizing PS1 Brace Expansion Bash Arithmetic getopts : smart positional-parameter parsing Debugging Pitfalls Script shebang Pattern matching and regular expressions Keyboard shortcuts Change shell Copying (cp)Internal variables Job Control Case statement Word splitting Read a file (data stream, variable) line-by-line (and/or field-by-field)?File Transfer using scp Pipelines Managing PATH environment variable Avoiding date using printf Chain of commands and operations Type of Shells true, false and : commands Color script output (cross-platform)Navigating directories Using sort Namespace co-processes Typing variables Jobs at specific times Associative arrays Handling the system prompt Creating directories File execution sequence The cut command Bash on Windows 10 Cut Command Splitting Files global and local variables Design Patterns CGI Scripts Select keyword When to use eval Networking With Bash Parallel Grep strace Sleep utility Decoding URL

true, false and : commands

Infinite Loop

while true; do
    echo ok
done

or

while :; do
   echo ok
done

or

until false; do
    echo ok
done

Function Return

function positive() {
    return 0
}

function negative() {
    return 1
}

Code that will always/never be executed

if true; then
    echo Always executed
fi
if false; then
    echo Never executed
fi

Syntax:

true, : - always return 0 as exit code.
false - always returns 1 as exit code.

Contributors

Topic Id: 6655

Example Ids: 22660,22661,22662

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