0917 Lexical analysis

#include <stdio.h>
#include <string.h>//strcmp ()
#include <conio.h>//getch ()
#define MAX 200
Char Pro[max], lin[20];
int N,i,syn;
Char *word[6]={' begin ', ' if ', ' then ', ' while ', ' Do ', ' end '}; keywords, special identifiers
Char ch;
Scaner ()//scan
{
int j=0;
for (n=0; n<20; n++)
Lin[n]=null; Temporary array Initialization
ch=pro[i++];//reading a string
while (ch== ")//judge, skip null characters
ch=pro[i++];//reading the whole word
if ((ch>= ' A ' &&ch<= ' Z ') | | (ch>= ' A ' &&ch<= ' z ') | |        (ch>=48&&ch<=57)) Determine if it is a letter or a number
{
if ((ch>= ' A ' &&ch<= ' Z ') | |                       (ch>= ' A ' &&ch<= ' Z ')) Judging identifiers and Special keywords
{
Lin[j++]=ch;
ch=pro[i++];//pro[i++] Empty, keyword
while ((ch>= ' A ' &&ch<= ' Z ') | | (ch>= ' A ' &&ch<= ' z ') | | (ch>=48&&ch<=57)) Judging identifiers
{
Lin[j++]=ch;
Ch=pro[i++];
}
lin[j]= ' + ';//end sign, enter
i--;
syn=10;//Word species code
for (n=0;n<6; n++)
if (strcmp (Lin,word[n]) ==0)//Find out if the keyword table matches
{
syn=n+1;
break;
}
}
else//Judging numbers
{
while (ch>=48&&ch<=57)
{
Lin[j++]=ch;
Ch=pro[i++];
}
i--;
lin[j]= ' + ';
syn=11;
}
}
else//Judging other symbols
{
Judgment <,<=,<>


if (ch== ' < ')
{
Lin[j++]=ch;
Ch=pro[i++];
if (ch== ' = ')
{
syn=21;
Lin[j++]=ch;
lin[j]= ' + ';
}
else if (ch== ' > ')
{
syn=22;
Lin[j++]=ch;
lin[j]= ' + ';
}
Else
{
syn=20;
lin[j]= ' + ';
i--;
}
}
Judging >,>=
else if (ch== ' > ')
{
Lin[j++]=ch;
Ch=pro[i++];
if (ch== ' = ')
{
syn=24;
Lin[j++]=ch;
lin[j]= ' + ';
}
Else
{
syn=23;
lin[j]= ' + ';
i--;
}
}
Judgment:,: =
else if (ch== ': ')
{
Lin[j++]=ch;
Ch=pro[i++];
if (ch== ' = ')
{
syn=18;
Lin[j++]=ch;
lin[j]= ' + ';
}
Else
{
syn=17;
lin[j]= ' + ';
i--;
}
}
Judging other symbols
else if (ch== ' + ')
{
syn=13;
Lin[j++]=ch;
lin[j]= ' + ';
}
else if (ch== '-')
{
syn=14;
Lin[j++]=ch;
lin[j]= ' + ';
}
else if (ch== ' * ')
{
syn=15;
Lin[j++]=ch;
lin[j]= ' + ';
}
else if (ch== '/')
{
syn=16;
Lin[j++]=ch;
lin[j]= ' + ';
}
else if (ch== ' = ')
{
syn=25;
Lin[j++]=ch;
lin[j]= ' + ';
}
else if (ch== '; ')
{
syn=26;
Lin[j++]=ch;
lin[j]= ' + ';
}
else if (ch== ' (')
{
syn=27;
Lin[j++]=ch;
lin[j]= ' + ';
}
else if (ch== ') ')
{
syn=28;
Lin[j++]=ch;
lin[j]= ' + ';
}
else if (ch== ' # ')
{
syn=0;
Lin[j++]=ch;
lin[j]= ' + ';
}
Else
Syn=-1;
}
Return SYN;
}
void read ()//read-in data function
{
FILE *FP;
int k;
for (k=0;k<max-1;k++)
{
scanf (FP, "%c", &pro[k]);
}
pro[k]= ' + ';
}
void Main ()

{
printf ("Please input source code:\n");
do{
Ch=getchar ();//Read into string
Pro[i++]=ch;
}while (ch!= ' # ');
i=0;

Do
{
Scaner ();
Switch (SYN)
{
Case 11:printf ("(%d,%s) \ n", Syn,lin);
Break
Case-1: printf ("error symbol \ n");
Break
Default:printf ("(%d,%s) \ n", Syn,lin);
}
} while (syn!=0);
Getch ();
}

0917 Lexical analysis