number1.l

一个词法分析实验的源代码

%{
#include <string.h>
#include <stdlib.h>
#define LEN sizeof(struct ident)

struct ident
{
	char *str;
	int num;
	struct ident *next;
};
struct ident *Keyword=NULL; 
struct ident *Identifier=NULL;
FILE *fp;
char *Integer[100];
char *Float[100];
int IntNum=0, FloatNum=0,OperNum=0,SymNum=0;  //这些用来计数

void InsertKey(char *newone)
{
	struct ident *p,*q;
	struct ident *news;
	if(strcmp(newone,Keyword->str)==0)
	{
		Keyword->num++;
		return;
	}
    p=Keyword;
    q=Keyword;
    p=p->next;
    while(p!=NULL)
    {
		if( strcmp(newone,p->str)==0)
			break;
		p=p->next;
	    q=q->next;
	}
	if(p==NULL)
	{
		news=(struct ident *)malloc(LEN);
		news->str=(char *)malloc(sizeof(newone)+1);
	    strcpy(news->str,newone);
	   	news->num=1;
	   	q->next=news;
	   	news->next=NULL;
	}
	else
	{
		p->num++;
	}
}	
void InsertId(char *newone)
{
	struct ident *p,*q;
	struct ident *news;
	if(strcmp(newone,Identifier->str)==0)
	{
		Identifier->num++;
		return;
	}
    p=Identifier;
	q=Identifier;
    p=p->next;
    while(p!=NULL)
    {
		if( strcmp(newone,p->str)==0)
			break;
		p=p->next;
	    q=q->next;
	}
	if(p==NULL)
	{
		news=(struct ident *)malloc(LEN);
        news->str=(char *)malloc(sizeof(newone)+1);
		strcpy(news->str,newone);
		news->num=1;
		q->next=news;
		news->next=NULL;
	}
	else
	{
		p->num++;
	}
}	

void AddToKey(char *newone)
{
	if(Keyword==NULL)
	{
		Keyword=(struct ident *)malloc(LEN);
        Keyword->str=(char *)malloc(sizeof(newone)+1);
		strcpy(Keyword->str,newone);
		Keyword->num=1;
		Keyword->next=NULL;
	}
	else
	{
		InsertKey(newone);
	
	}

}

void AddToId(char *newone)
{
	if(Identifier==NULL)
	{
		Identifier=(struct ident *)malloc(LEN);
        Identifier->str=(char *)malloc(sizeof(newone)+1);
		strcpy(Identifier->str,newone);
		Identifier->num=1;
		Identifier->next=NULL;
	}
	else
	{
		InsertId(newone);
	
	}

}


void print()
{
        int i,j;
	struct ident *s,*p;
	p=Keyword;
        fprintf(fp,"关键字如下：\n");
	while(p!=NULL)
	{
		fprintf(fp,"%20s %3d time(s)\n",p->str,p->num);
        p=p->next;
	}
        fprintf(fp,"识别的变量如下：\n");
	s=Identifier;
	while(s!=NULL)
	{
		fprintf(fp,"%20s %3d time(s)\n",s->str,s->num);
        s=s->next;
	}

        fprintf(fp,"整数总数：       %d\n",IntNum);
        for(i=0;i<IntNum;i++)
             fprintf(fp,"%s\n",Integer[i]);
        fprintf(fp,"\n");
        fprintf(fp,"浮点数总数：     %d\n",FloatNum);
        for(j=0;j<FloatNum;j++)
             fprintf(fp,"%s\n",Float[j]);
        fprintf(fp,"\n");	
	fprintf(fp,"运算符号：(+-*/=())共有   %d time(s)\n",OperNum);
	fprintf(fp,"标点符号：(,;)共有        %d time(s)\n",SymNum);
	
		
}
%}
INTEGER [0-9]
ID [a-zA-Z][A-Za-z0-9]*

%%
{INTEGER}+   {Integer[IntNum]=(char *)malloc(sizeof(yytext)+1);strcpy(Integer[IntNum],yytext); IntNum++;}//当出现整数时
{INTEGER}+"."{INTEGER}*   {Float[FloatNum]=(char *)malloc(sizeof(yytext)+1);strcpy(Float[FloatNum],yytext); FloatNum++;}   //当出现浮点数时

if|then|begin|end|procedure|while|do|read|write|call|const|var|odd   { AddToKey(yytext); }

{ID}     {   AddToId(yytext);  }     //当出现其他字符串时

"+"|"-"|"*"|"/"|"="|"("|")"  {  OperNum++; } //当出现这些运算浮时

";"|","      { SymNum++; }  //当出现； 和 ，时

"{"[^}\n]*"}"    { }   //将这些符号略去，不做统计
 
[ \t\n]+ {}  //空格和换行浮不做统计

. {  
fprintf( fp,"Unrecognized: %s\n", yytext );  
} 

%%

int yywrap()
{
	return 1;
}

main( argc, argv )
int argc;
char **argv;
{
         ++argv; --argc;
         if( argc > 0)
        {
	        yyin = fopen( argv[0], "r" );
		fp=fopen("output.txt","w");
		yylex();                                    
		fprintf(fp,"\n             下面是词法分析结果 : \n");
                print();
		fclose(fp);
		printf("词法分析结束，请打开output.txt查看结果 .\n");
        }
	else
	{
	        printf("对不起，没有找到源文件。请重试！！ \n");
	}

	return 0;
}