C program for Lexical Analyzer

#include<iostream.h>
#include<conio.h>
#include<stdio.h>
#include<string.h>
#include<stdlib.h>
#include<ctype.h>
struct pgm
{
char line[20];
} s[100];
void check(char s[])
{
cout<<"\n";
if(!strcmpi(s,"If"))
{
cout<<"keyword:If";
return;
}
if(!strcmpi(s,"Then"))
{
cout<<"keyword:Then";
return;
}
if(!strcmpi(s,"Else"))
{
cout<<"keyword:else";
return;
}
if(!strcmpi(s,"[END]"))
{
return;
}
cout<<"expression:"<<s;
}
void main()
{
char t[20];
int i=0,j=0,k=0;
clrscr();
cout<<"\n\n enter the program code:(to stop input type End)\n";
do
{
gets(s[i].line);
}
while(strcmpi(s[i++].line,"END"));
k = k-1;
do
{
k++;
for(i=0;s[k].line[i]!='\0';i++,j++)
{
if(s[k].line[i]==' ')
{
t[j]='\0';
j=-1;
check(t);
}
else
t[j]=s[k].line[i];
}
t[j]='\0';
j=0;
check(t);
}
while(strcmpi(s[k].line,"END"));
getch();
}

#include<iostream.h> #include<conio.h> #include<stdio.h> #include<string.h> #include<stdlib.h> #include<ctype.h> struct pgm { char line[20]; } s[100]; void check(char s[]) { cout<<"\n"; if(!strcmpi(s,"If")) { cout<<"keyword:If"; return; } if(!strcmpi(s,"Then")) { cout<<"keyword:Then"; return; } if(!strcmpi(s,"Else")) { cout<<"keyword:else"; return; } if(!strcmpi(s,"[END]")) { return; } cout<<"expression:"<<s; } void main() { char t[20]; int i=0,j=0,k=0; clrscr(); cout<<"\n\n enter the program code:(to stop input type End)\n"; do { gets(s[i].line); } while(strcmpi(s[i++].line,"END")); k = k-1; do { k++; for(i=0;s[k].line[i]!='\0';i++,j++) { if(s[k].line[i]==' ') { t[j]='\0'; j=-1; check(t); } else t[j]=s[k].line[i]; } t[j]='\0'; j=0; check(t); } while(strcmpi(s[k].line,"END")); getch(); }