Karl Berry Olaf Bachmann and many others. The following may appear anywhere in a simple command or may precede or follow a complex command.
Expansion occurs before word or digit is used except as noted below.
If the result of substitution on word produces more than one filename, redirection occurs for each separate filename in turn. If the file does not exist then it is created. If the file does not exist then it is created. No parameter expansion, command substitution or filename generation is performed on word . The resulting document, called a here-document , becomes the standard input.