103 lines
3.3 KiB
Plaintext
103 lines
3.3 KiB
Plaintext
https://pubs.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#tag_18_10_02
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/* -------------------------------------------------------
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The grammar symbols
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------------------------------------------------------- */
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%token WORD
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%token LESS // '<'
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%token GREAT // '>'
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%token DLESS // '<<'
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%token DGREAT // '>>'
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%token PIPE // '|'
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/* -------------------------------------------------------
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The Simplified Grammar
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------------------------------------------------------- */
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%start program
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%%
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pipeline : command
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| pipe_sequence '|' command
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;
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command : cmd_prefix cmd_name cmd_suffix
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| cmd_prefix cmd_name
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| cmd_name cmd_suffix
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| cmd_name
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;
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cmd_name : WORD // Apply rule 7a
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;
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cmd_prefix : io_redirect
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| cmd_prefix io_redirect
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;
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cmd_suffix : io_redirect
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| cmd_suffix io_redirect
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| WORD
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| cmd_suffix WORD
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;
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io_redirect : io_file
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| io_here
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;
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io_file : '<' filename
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| LESSAND filename
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| '>' filename
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| GREATAND filename
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| DGREAT filename
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| LESSGREAT filename
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| CLOBBER filename
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;
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filename : WORD // Apply rule 2
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;
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io_here : DLESS here_end
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;
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here_end : WORD // Apply rule 3
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;
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/* -------------------------------------------------------
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The Grammar
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------------------------------------------------------- */
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%start program
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%%
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pipeline : pipe_sequence
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;
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pipe_sequence : command
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| pipe_sequence '|' command
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;
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command : simple_command
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;
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simple_command : cmd_prefix cmd_word cmd_suffix
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| cmd_prefix cmd_word
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| cmd_prefix
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| cmd_name cmd_suffix
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| cmd_name
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;
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cmd_name : WORD /* Apply rule 7a */
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;
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cmd_word : WORD /* Apply rule 7b */
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;
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cmd_prefix : io_redirect
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| cmd_prefix io_redirect
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;
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cmd_suffix : io_redirect
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| cmd_suffix io_redirect
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| WORD
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| cmd_suffix WORD
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;
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io_redirect : io_file
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| io_here
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;
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io_file : '<' filename
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| LESSAND filename
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| '>' filename
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| GREATAND filename
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| DGREAT filename
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| LESSGREAT filename
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| CLOBBER filename
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;
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filename : WORD /* Apply rule 2 */
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;
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io_here : DLESS here_end
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;
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here_end : WORD /* Apply rule 3 */
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;
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