bash(1) Mac OS X Manual Page

bash(1) Mac OS X Manual Page:

DEFINITIONS
       The following definitions are used throughout the rest of this document.
       blank  A space or tab.
       word   A sequence of characters considered as a single unit by the shell.  Also known as a token.
       name   A word consisting only of alphanumeric characters  and  underscores,  and  beginning  with  an
              alphabetic character or an underscore.  Also referred to as an identifier.
       metacharacter
              A character that, when unquoted, separates words.  One of the following:
              |  & ; ( ) < > space tab

  control operator

              A token that performs a control function.  It is one of the following symbols:
              || & && ; ;; ( ) | 

RESERVED WORDS
       Reserved  words  are  words that have a special meaning to the shell.  The following words are recog-
       nized as reserved when unquoted and either the first word of a  simple  command  (see  SHELL  GRAMMAR
       below) or the third word of a case or for command:

       ! case  do done elif else esac fi for function if in select then until while { } time [[ ]]

SHELL GRAMMAR
   Simple Commands
       A simple command is a sequence of optional variable assignments followed by blank-separated words and
       redirections, and terminated by a control operator.  The first word specifies the command to be  exe-
       cuted,  and  is  passed as argument zero.  The remaining words are passed as arguments to the invoked
       command.

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