Arguments Shell parameters Variables Variable Substitution List of Environment variables List of Special bash shell variables Array Variables functions Define Function Macros Redirection Redirect output from one command as input for another
if Conditionally perform a command for Expand words, and execute commands while Execute commands The break and continue builtins may be used to control loop execution.
Using brackets to Group and expand expressions Logical, arithmetical and comparison operators Conditional execution command-A AND/OR command-B Comparison Operators exists, greater than, equal to Escape Characters, delimiters and Quotes File operators -f Command Substitution
Working with the bash Shell:
Run a bash shell script Prompt Statement variables Bash startup files bashrc Here documents and Here Strings strftime Date and time string formats
Keyboard Shortcuts - bash Terminal Keyboard Shortcuts - macOS Key Bindings Create a bootable OS X drive Defaults - A list of macOS preferences macOS Root user - How to Enable/Disable macOS Filesystem hierarchy Background Processes (Westwind) Valid Filenames in macOS
For examples of all the above see macOS books