Write a lexical analyzer which reads a C- program

#include<stdio.h> #include<string.h> #include<stdlib.h> void removeduplicate(); void final(); int Isiden(char ch); int Isop(char ch); int Isdel(char ch); int Iskey(char * str); void removeduplicate(); char op[8]={'+','-','*','/','=','<','>','%'}; char del[8]={'}','{',';','(',')','[',']',','}; char *key[]={"int","void","main","char","float", "if", "else"}; int idi=0,idj=0,k,opi=0,opj=0,deli=0,uqdi=0,uqidi=0,uqoperi=0,kdi=0,liti=0,ci=0; int num1=1, num2=2, num3, num4=4, num5=5; int uqdeli[20],uqopi[20],uqideni[20],l=0,j; char uqdel[20],uqiden[20][20],uqop[20][20],keyword[20][20]; char iden[20][20],oper[20][20],delem[20],litral[20][20],lit[20],constant[20][20]; void lexanalysis(char *str) { int i=0; while(str[i]!='\0') { if(Isiden(str[i])) //for identifiers { while(Isiden(str[i])) { iden[idi][idj++]=str[i++]; } iden[idi][idj]='\0'; idi++;idj=0; } else if(str[i]=='"') //for literals { lit[l++]=str[i]; for(j=i+1;str[j]!='"';j++) { lit[l++]=str[j]; } lit[l++]=str[j];lit[l]='\0'; strcpy(litral[liti++],lit); i=j+1; } else if(Isop(str[i])) // for operators { while(Isop(str[i])) { oper[opi][opj++]=str[i++]; } oper[opi][opj]='\0'; opi++;opj=0; } else if(Isdel(str[i])) //for delemeters { while(Isdel(str[i])) { delem[deli++]=str[i++]; } } else { i++; } } removeduplicate(); final(); } int Isiden(char ch) { if(isalpha(ch)||ch=='_'||isdigit(ch)||ch=='.') return 1; else return 0; } int Isop(char ch) { int f=0,i; for(i=0;i<8&&!f;i++) { if(ch==op[i]) f=1; } return f; } int Isdel(char ch) { int f=0,i; for(i=0;i<8&&!f;i++) { if(ch==del[i]) f=1; } return f; } int Iskey(char * str) { int i,f=0; for(i=0;i<5;i++) { if(!strcmp(key[i],str)) f=1; } return f; } void removeduplicate() { int i,j; for(i=0;i<20;i++) { uqdeli[i]=0; uqopi[i]=0; uqideni[i]=0; } for(i=1;i<deli+1;i++) //removing duplicate delemeters { if(uqdeli[i-1]==0) { uqdel[uqdi++]=delem[i-1]; for(j=i;j<deli;j++) { if(delem[i-1]==delem[j]) uqdeli[j]=1; } } } for(i=1;i<idi+1;i++) //removing duplicate identifiers { if(uqideni[i-1]==0) { strcpy(uqiden[uqidi++],iden[i-1]); for(j=i;j<idi;j++) { if(!strcmp(iden[i-1],iden[j])) uqideni[j]=1; } } } for(i=1;i<opi+1;i++) //removing duplicate operators { if(uqopi[i-1]==0) { strcpy(uqop[uqoperi++],oper[i-1]); for(j=i;j<opi;j++) { if(!strcmp(oper[i-1],oper[j])) uqopi[j]=1; } } } } void final() { int i=0; idi=0; for(i=0;i<uqidi;i++) { if(Iskey(uqiden[i])) //identifying keywords strcpy(keyword[kdi++],uqiden[i]); else if(isdigit(uqiden[i][0])) //identifying constants strcpy(constant[ci++],uqiden[i]); else strcpy(iden[idi++],uqiden[i]); } // printing the outputs printf("\n\tDelemeter are : \n"); for(i=0;i<uqdi;i++) printf("\t%c\n",uqdel[i]); printf("\n\tOperators are : \n"); for(i=0;i<uqoperi;i++) { printf("\t"); puts(uqop[i]); } printf("\n\tIdentifiers are : \n"); for(i=0;i<idi;i++) { printf("\t"); puts(iden[i]); } printf("\n\tKeywords are : \n"); for(i=0;i<kdi;i++) { printf("\t"); puts(keyword[i]); if(keyword[i] == "if") { printf("1"); } } printf("\n\tConstants are :\n"); for(i=0;i<ci;i++) { printf("\t"); puts(constant[i]); } printf("\n\tLiterals are :\n"); for(i=0;i<liti;i++) { printf("\t"); puts(litral[i]); } } void main() { char str[50]; //clrscr(); printf("\nEnter the string : "); scanf("%[^\n]c",str); lexanalysis(str); //getch(); }