$1.*$parser$.$h$*$

c

#ifndef PARSER$\_$H

#define PARSER$\_$H

void program$()$;

void statement$()$;

void forStatement$()$;

void ifStatement$()$;

void whileStatement$()$;

void doWhileStatement$()$;

void expression$()$;

void condition$()$;

void match$($int expectedToken$)$;

#endif $//$ PARSER$\_$H

$2.*$parser$.$c$*$

c

#include

#include

#include "token.h$"$

#include "parser.h$"$

void program$()\{$

getChar$()$;

lex$()$;

while $($nextToken $!=$ EOF$\_$TOKEN$)\{$

statement$()$;

$\}$

$\}$

void statement$()\{$

switch $($nextToken$)\{$

case FOR$\_$CODE: forStatement$()$; break;

case IF$\_$CODE: ifStatement$()$; break;

case WHILE$\_$CODE: whileStatement$()$; break;

case DO$\_$CODE: doWhileStatement$()$; break;

default: printf$("$Syntax error: invalid statement

$")$; exit$(1)$;

$\}$

$\}$

void forStatement$()\{$

match$($FOR$\_$CODE$)$;

match$($LEFT$\_$PAREN$)$;

expression$()$;

match$($SEMICOLON$)$;

condition$()$;

match$($SEMICOLON$)$;

expression$()$;

match$($RIGHT$\_$PAREN$)$;

match$($LEFT$\_$BRACE$)$;

while $($nextToken $!=$ RIGHT$\_$BRACE$)\{$ statement$()$; $\}$

match$($RIGHT$\_$BRACE$)$;

$\}$

void ifStatement$()\{$

match$($IF$\_$CODE$)$;

match$($LEFT$\_$PAREN$)$;

condition$()$;

match$($RIGHT$\_$PAREN$)$;

match$($LEFT$\_$BRACE$)$;

while $($nextToken $!=$ RIGHT$\_$BRACE$)\{$ statement$()$; $\}$

match$($RIGHT$\_$BRACE$)$;

if $($nextToken $==$ ELSE$\_$CODE$)\{$

match$($ELSE$\_$CODE$)$;

match$($LEFT$\_$BRACE$)$;

while $($nextToken $!=$ RIGHT$\_$BRACE$)\{$ statement$()$; $\}$

match$($RIGHT$\_$BRACE$)$;

$\}$

$\}$

void whileStatement$()\{$

match$($WHILE$\_$CODE$)$;

match$($LEFT$\_$PAREN$)$;

condition$()$;

match$($RIGHT$\_$PAREN$)$;

match$($LEFT$\_$BRACE$)$;

while $($nextToken $!=$ RIGHT$\_$BRACE$)\{$ statement$()$; $\}$

match$($RIGHT$\_$BRACE$)$;

$\}$

void doWhileStatement$()\{$

match$($DO$\_$CODE$)$;

match$($LEFT$\_$BRACE$)$;

while $($nextToken $!=$ RIGHT$\_$BRACE$)\{$ statement$()$; $\}$

match$($RIGHT$\_$BRACE$)$;

match$($WHILE$\_$CODE$)$;

match$($LEFT$\_$PAREN$)$;

condition$()$;

match$($RIGHT$\_$PAREN$)$;

match$($SEMICOLON$)$;

$\}$

void expression$()\{$

lex$()$;

$\}$

void condition$()\{$

lex$()$;

$\}$

void match$($int expectedToken$)\{$

if $($nextToken $==$ expectedToken$)\{$

lex$()$;

$\}$ else $\{$

printf$("$Syntax error: expected token $\%$d

$",$ expectedToken$)$;

exit$(1)$;

$\}$

$\}$

int main$()\{$

if $(($in$\_$fp $=$ fopen$("$front$.$in$","$r$"))==$ NULL$)\{$

printf$("$ERROR $-$ cannot open front.in

$")$;

return $1$;

$\}$ else $\{$

program$()$;

printf$("$Parsing completed successfully.

$")$;

fclose$($in$\_$fp$)$;

$\}$

return $0$;

$\}$

$3.*$token$.$h$*$

c

#ifndef TOKEN$\_$H

#define TOKEN$\_$H

#include

$//$ Token definitions

enum $\{$

EOF$\_$TOKEN, how can I run these files in ubuntu in the same director