grammar.txt

Tokens:

	NEWLINE             '\n'
	WORD
	NAME
	PARAMETER_EXPANSION '$...'
	INPUT_REDIRECT      '<'
	OUTPUT_REDIRECT     '>'
	PIPE                '|'
	ASYNC_LIST          '&'
	SEQ_LIST            ';'
	IF                  'if'
	ELSE                'else'
	FI                  'fi'
	THEN                'then'
	FOR                 'for'
	WHILE               'while'
	DO                  'do'
	DONE                'done'
	IN                  'in'
	INTEGER
	PLUS                '+'
	MINUS               '-'
	MULTIPLY            '*'
	DIVIDE              '/'
	LPAR                '('
	RPAR                ')'
	END

compound_list :              term
              | newline_list term
              |              term newline_list
              | newline_list term newline_list

term : cc_list term
     | list    term
     | list
     | cc_list

cc_list : cc_list newline_list compound_command
        |                      compound_command
        |         newline_list compound_command

compound_command: for_clause
                | if_clause
                | while_clause

if_clause : If compound_list Then compound_list else_part Fi
          | If compound_list Then compound_list           Fi

else_part: Else compound_list

while_clause: While compound_list do_group

do_group : Do compound_list Done

for_clause : For WORD linebreak                          do_group
           | For WORD linebreak In wordlist newline_list do_group

wordlist : wordlist WORD
         | wordlist PARAMETER_EXPANSION
         | wordlist arithm_expression
         |          WORD
         |          PARAMETER_EXPANSION
         |          arithm_expression

list : newline_list pipeline_list
     |              pipeline_list

pipeline_list : pipeline_list separator pipeline
              | pipeline_list separator
              |                         pipeline

separator : separator_op linebreak
          | newline_list

separator_op : ASYNC_LIST
             | SEQ_LIST

newline_list :              NEWLINE
             | newline_list NEWLINE

linebreak : newline_list
          | 'empty'

simple_command : cmd_prefix cmd_name cmd_suffix
               | cmd_prefix cmd_name
               | cmd_prefix
               |            cmd_name cmd_suffix
               |            cmd_name

cmd_prefix :            NAME'='WORD
           |            NAME'='PARAMETER_EXPANSION
           |            NAME'='arithm_expression
           | cmd_prefix NAME'='WORD
           | cmd_prefix NAME'='PARAMETER_EXPANSION
           | cmd_prefix NAME'='arithm_expression

cmd_name : WORD
         | PARAMETER_EXPANSION

cmd_suffix :	        io_redirect
           | cmd_suffix io_redirect
           |            WORD
           |            PARAMETER_EXPANSION
           |            arithm_expression
           | cmd_suffix WORD
           | cmd_suffix PARAMETER_EXPANSION
           | cmd_suffix arithm_expression

arithm_expression : arithm_term
                  | arithm_term (PLUS  arithm_term)*
                  | arithm_term (MINUS arithm_term)*

arithm_term : arithm_factor
            | arithm_factor (MULTIPLY arithm_factor)*
            | arithm_factor (DIVIDE   arithm_factor)*

arithm_factor : INTEGER
              | PARAMETER_EXPANSION
              | LPAR arithm_expression RPAR
              | PLUS  arithm_factor
              | MINUS arithm_factor

filenme: WORD
       | PARAMETER_EXPANSION

io_redirect : INPUT_REDIRECT  filename
            | OUTPUT_REDIRECT filename