#include<stdio.h>

#include<string.h>

#include<conio.h>

#include<ctype.h>

FILE *fp;

char delim[14]={' ','\t','\n',',',';','(',')','{','}','[',']','#','<','>'};

char oper[7]={'+','-','*','/','%','=','!'};

char key[21][12]={"int","float","char","double","bool","void","extern","unsigned","goto","static","class","struct","for","if","else","return","register","long","while","do"};

char predirect[2][12]={"include","define"};

char header[6][15]={"stdio.h","conio.h","malloc.h","process.h","string.h","ctype.h"};

void skipcomment();

void analyze();

void check(char []);

int isdelim(char);

int isop(char);

int fop=0,numflag=0,f=0;

char c,ch,sop;

void main()

{

char fname[12];

clrscr();

printf("\n enter filename:");

scanf("%s",fname);

fp=fopen(fname,"r");

if(fp==NULL)

printf("\n the file does not exist");

else

analyze();

printf("\n end of file \n");

getch();

}

void analyze()

{

char token[50];

int j=0;

while(!feof(fp))

{

c=getc(fp);

if(c=='/')

{

//skip comment();

}

else if(c==’ ‘)

while((c=getc(fp))!="");

else if(isalpha(c))

{

if(numflag==1)

{

token[j]='\0';

check(token);

numflag=0;

j=0;

f=0;

}

else

{

token[j]=c;

j++;

}

if(f==0)

f=1;

}

else if(isalnum(c))

{

if(numflag==0)

numflag=1;

token[j]=c;

j++;

}

else

{

if(isdelim(c))

{

if(numflag==1)

{

token[j]='\0';

check(token);

numflag=0;

}

if(f==1)

{

token[j]='\0';

numflag=0;

check(token);

}

j=0;

f=0;

printf("\n delimiters \t%c",c);

}

else if(isop(c))

{

if(numflag==1)

{

token[j]='\0';

check(token);

numflag=0;

j=0;

f=0;

}

if(f==1)

{

token[j]='\0';

j=0;

f=0;

numflag=0;

check(token);

}

if(fop==1)

{

fop=0;

printf("\n operator \t %c%c",c,sop);

}

else

printf("\n operator \t%c",c);

}

else if(c=='.')

{

token[j]=c;

j++;

}

}

}

}

int isdelim(char c)

{

int i;

for(i=0;i<14;i++)

{

if(c==delim[i])

return 1;

}

return 0;

}

int isop(char c)

{

int i,j;

char ch;

for(i=0;i<7;i++)

{

if(c==oper[i])

{

ch=getc(fp);

for(j=0;j<6;j++)

{

if(ch==oper[j])

{

fop=1;

sop=ch;

return 1;

}

}

ungetc(ch,fp);

return 1;

}

}

return 0;

}

void check(char t[])

{

int i;

if(numflag==1)

{

printf("\n number \t\t%s",t);

return;

}

for(i=0;i<2;i++)

{

if(strcmp(t,predirect[i])==0)

{

printf("\n preprocessor directive %s",t);

return;

}

}

for(i=0;i<6;i++)

{

if(strcmp(t,header[i])==0)

{

printf("\n header file \t%s",t);

return;

}

}

for(i=0;i<21;i++)

{

if(strcmp(key[i],t)==0)

{

printf("\n keyword \t\t%s",key[i]);

return;

}

}

printf("\n identifier \t%s",t);

}

void skipcomment()

{

ch=getc(fp);

if(ch=='/')

{

while((ch=getc(fp))!='\0');

}

else if(ch=='*')

{

while(f==0)

{

ch=getc(fp);

if(c=='/')

f=1;

}

}

f=0;

}