bash: Definitions

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1 2 Definitions
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1 These definitions are used throughout the remainder of this manual.
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1 'POSIX'
1      A family of open system standards based on Unix.  Bash is primarily
1      concerned with the Shell and Utilities portion of the POSIX 1003.1
1      standard.
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1 'blank'
1      A space or tab character.
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1 'builtin'
1      A command that is implemented internally by the shell itself,
1      rather than by an executable program somewhere in the file system.
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1 'control operator'
1      A 'token' that performs a control function.  It is a 'newline' or
1      one of the following: '||', '&&', '&', ';', ';;', ';&', ';;&', '|',
1      '|&', '(', or ')'.
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1 'exit status'
1      The value returned by a command to its caller.  The value is
1      restricted to eight bits, so the maximum value is 255.
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1 'field'
1      A unit of text that is the result of one of the shell expansions.
1      After expansion, when executing a command, the resulting fields are
1      used as the command name and arguments.
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1 'filename'
1      A string of characters used to identify a file.
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1 'job'
1      A set of processes comprising a pipeline, and any processes
1      descended from it, that are all in the same process group.
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1 'job control'
1      A mechanism by which users can selectively stop (suspend) and
1      restart (resume) execution of processes.
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1 'metacharacter'
1      A character that, when unquoted, separates words.  A metacharacter
1      is a 'space', 'tab', 'newline', or one of the following characters:
1      '|', '&', ';', '(', ')', '<', or '>'.
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1 'name'
1      A 'word' consisting solely of letters, numbers, and underscores,
1      and beginning with a letter or underscore.  'Name's are used as
1      shell variable and function names.  Also referred to as an
1      'identifier'.
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1 'operator'
11      A 'control operator' or a 'redirection operator'.  ⇒
      Redirections, for a list of redirection operators.  Operators
1      contain at least one unquoted 'metacharacter'.
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1 'process group'
1      A collection of related processes each having the same process
1      group ID.
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1 'process group ID'
1      A unique identifier that represents a 'process group' during its
1      lifetime.
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1 'reserved word'
1      A 'word' that has a special meaning to the shell.  Most reserved
1      words introduce shell flow control constructs, such as 'for' and
1      'while'.
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1 'return status'
1      A synonym for 'exit status'.
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1 'signal'
1      A mechanism by which a process may be notified by the kernel of an
1      event occurring in the system.
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1 'special builtin'
1      A shell builtin command that has been classified as special by the
1      POSIX standard.
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1 'token'
1      A sequence of characters considered a single unit by the shell.  It
1      is either a 'word' or an 'operator'.
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1 'word'
1      A sequence of characters treated as a unit by the shell.  Words may
1      not include unquoted 'metacharacters'.
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