jShell/shell.y at master · steve011/jShell · GitHub

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%{
	#include <stdio.h>
	#include <stdlib.h>
	#include <string.h>
	#include "shell.h"
	int yylex(void);
	void  yyerror(char*);
	char* str;
	int str_length;
%}

%union {
	int	i;
	char *s;
	char *w;
}

/*token definitions for built in functions*/
%token <i> SETENV PRINTENV UNSETENV CD ALIAS UNALIAS BYE

/*token definitions for metacharacters*/
%token <i> LT GT VERT QUOTE WACK AMP STDERR	STDOUT STDIN END WHITESPACE

%token <w> WORD
%token <s> STRING

%start line


%%

line:		END					{YYACCEPT;}
			| cmds END  		{YYACCEPT;}
			| cmds AMP END		{amp = 1; YYACCEPT;}
			| cmds redir END	{YYACCEPT;}
			| cmds redir AMP END{amp = 1; YYACCEPT;}

cmds:		cmd.args
			| cmd.args VERT cmds

cmd.args:	cmd args

cmd:		SETENV			{
								arg_counter = 0;
								Cmd* new_cmd = &cmd_table[cmd_counter];
								strcpy(new_cmd->cmdname, "setenv");
								new_cmd->bi_type = SET;
								new_cmd->num_args = 0;
								cmd_counter++;
								bi = SET;
							}

			| PRINTENV		{
								arg_counter = 0;
								Cmd* new_cmd = &cmd_table[cmd_counter];
								strcpy(new_cmd->cmdname, "printenv");
								new_cmd->bi_type = PRINT;
								new_cmd->num_args = 0;
								cmd_counter++;
								bi = PRINT;
							}

			| UNSETENV		{
								arg_counter = 0;
								Cmd* new_cmd = &cmd_table[cmd_counter];
								strcpy(new_cmd->cmdname, "unsetenv");
								new_cmd->bi_type = UNSET;
								new_cmd->num_args = 0;
								cmd_counter++;
								bi = UNSET;
							}

			| CD			{
								arg_counter = 0;
								Cmd* new_cmd = &cmd_table[cmd_counter];
								strcpy(new_cmd->cmdname, "cd");
								new_cmd->bi_type = CHANGE;
								new_cmd->num_args = 0;
								cmd_counter++;
								bi = CHANGE;
							}

			| ALIAS			{
								arg_counter = 0;
								Cmd* new_cmd = &cmd_table[cmd_counter];
								strcpy(new_cmd->cmdname, "alias");
								new_cmd->bi_type = AL;
								new_cmd->num_args = 0;
								cmd_counter++;
								bi = AL;
							}

			| UNALIAS		{
								arg_counter = 0;
								Cmd* new_cmd= &cmd_table[cmd_counter];
								strcpy(new_cmd->cmdname, "unalias");
								new_cmd->bi_type = UNAL;
								new_cmd->num_args = 0;
								cmd_counter++;
								bi = UNAL;
							}

			| BYE			{
								arg_counter = 0;
								Cmd* new_cmd = &cmd_table[cmd_counter];
								strcpy(new_cmd->cmdname, "bye");
								new_cmd->bi_type = BY;
								new_cmd->num_args = 0;
								cmd_counter++;
								bi = BY;
							}

			| WORD			{
								arg_counter = 0;
								Cmd* new_cmd = &cmd_table[cmd_counter];
								strcpy(new_cmd->cmdname, str);
								new_cmd->bi_type = 0;
								new_cmd->num_args = 0;
								cmd_counter++;
							}

args:		/*no arguments*/
			| args WORD		{
								Cmd* my_cmd = &cmd_table[cmd_counter-1];
								strcpy(my_cmd->arguments[arg_counter], str);
								arg_counter++;
								my_cmd->num_args = arg_counter;
							}
			| args quote	{
								Cmd* my_cmd = &cmd_table[cmd_counter-1];
								strcpy(my_cmd->arguments[arg_counter], temp);
								arg_counter++;
								my_cmd->num_args = arg_counter;
							}

quote:		QUOTE words QUOTE
			| QUOTE QUOTE	{strcpy(temp, "");}

words:		WORD			{
								strcat(temp, str);
							}
			| words WORD	{
								strcat(temp, " ");
								strcat(temp, str);
							}

redir:		input_red output_red err_red
			| input_red err_red output_red
			| output_red input_red err_red
			| output_red err_red input_red
			| err_red input_red output_red
			| err_red output_red input_red

input_red:	LT infile		{
								inFile_red = 1;
							}

output_red:	GT outfile		{
								outFile_red = 1;
							}

			| GT GT outfile	{
								outFile_red = 1;
								append = 1;
							}

err_red:	STDERR GT errfile	{
									errFile_red = 1;
								}

infile:		WORD			{
								strcpy(inFile, str);
							}

outfile:	WORD			{
								strcpy(outFile, str);
							}

errfile:	WORD			{
								strcpy(errFile, str);
							}


%%
void yyerror(char *s) {
	fprintf(stderr, "%s\n", s);
}