词法分析程序2

#include <stdio.h>
#include <string.h>
char c[80],t[8],ch;
int s,p,m,n,sum;
char *w[6]={"begin","if","then","while","do","end"};
void scaner();
main()
{
 p=0;
 printf("请输入一段字符(以‘#‘结束)");
 do{
    scanf("%c",&ch);
    c[p++]=ch;       
    }while(ch!=‘#‘);
 p=0;
 do{
    scaner();
    switch(s)
     {
      case 11:printf("< %-10d%5d>\n",sum,s);
          break;
      case -1:printf("你输入了错误的单词符号\n");
          getch();
          exit(0);
      default: printf("<%-10s%5d >\n",t,s);
          break;
      }
    }while(s!=0);
    getch();
 }

void scaner()
 {  
	sum=0;
    for(m=0;m<8;m++)
        t[m++]=NULL;
    ch=c[p++];
    m=0;
    while((ch==‘ ‘)||(ch==‘\n‘))
    ch=c[p++];
    if(((ch<=‘z‘)&&(ch>=‘a‘))||((ch<=‘Z‘)&&(ch>=‘A‘)))
      { 
      while(((ch<=‘z‘)&&(ch>=‘a‘))||((ch<=‘Z‘)&&(ch>=‘A‘))||((ch>=‘0‘)&&(ch<=‘9‘)))
      {
		  t[m++]=ch;
          ch=c[p++];
      }
      p--;
      s=10;
      for(n=0;n<6;n++)
    if(strcmp(t,w[n])==0)
       { 
		s=n+1;
         break;
       }
      }
    else if((ch>=‘0‘)&&(ch<=‘9‘))
      { 
		while((ch>=‘0‘)&&(ch<=‘9‘))
		{ sum=sum*10+ch-‘0‘;
          ch=c[p++];
		}
    p--;
    s=11;
      }
    else switch(ch)
    { 
     case ‘<‘:t[m++]=ch;
          ch=c[p++];
		   if(ch==‘>‘)
            {  s=22;
               t[m++]=ch;
            }
          else
            { 
			  s=20;
               p--;
		  }
		   if(ch==‘=‘)
            {  s=21;
               t[m++]=ch;
            }
			 
          break;
     case ‘>‘:t[m++]=ch;
          ch=c[p++];
          if(ch==‘=‘)
            { s=24;
              t[m++]=ch;
            }
          else
            { s=23;
              p--;
            }
          break;
     case ‘+‘: s=13;
             t[m++]=ch;
             break;

     case ‘-‘:
            s=14;
            t[m++]=ch;  
          break;

     case ‘!‘:ch=c[p++];
          if(ch==‘=‘)
           { s=30;
             t[m++]=ch;
           }
          else
          { s=31;
             p--;
          }
          break;

     case ‘=‘:
            s=25;
            t[m++]=ch;
            break;

     case ‘*‘: s=15;
           t[m++]=ch;         
		   break;

     case ‘/‘: s=16;
           t[m++]=ch;
           break;
     case ‘(‘: s=27;
           t[m++]=ch;
           break;
     case ‘)‘: s=28;
           t[m++]=ch;
           break;
     case ‘{‘: s=5;
           t[m++]=ch;
           break;
     case ‘}‘: s=6;
           t[m++]=ch;
           break;
     case ‘;‘: s=26;
          t[m++]=ch;
          break;
     case ‘\"‘: s=32;
           t[m++]=ch;
           break;
     case ‘#‘: s=0;
           t[m++]=ch;
           break;
     case ‘:‘:t[m++]=ch;
          ch=c[p++];
           if(ch==‘=‘)
            {  s=18;
               t[m++]=ch;
            }
		   else
          { s=17;
             p--;
		  }
           break;
    default: s=-1;
         break;
       }
	   t[m++]=‘\0‘;
  }