221105027_计续本05_李超_编译词法分析.c

词法分析

#include<stdio.h>
#include<ctype.h>
#define keywordSum 8

char * keyword[keywordSum]={"if","else","for","while","do","int","read","write"};
char singleword[50]="-*/(){};,:!";
char doubleword[10]="><=!&|";
extern char Scanin[300]，Scanout[300];
Extern FILE *fin，*fout;

int TESTscan()
{
	char ch, token[40];
	int es=0,j,n;

	printf("请输入源程序文件名(包括路径)：");
	scanf("%s",Scanin);
	if ((fin=fopen(Scanin,"r"))==NULL)
	{
		printf(“\n 打开词法分析输入文件出错！\n");
		return(1);
	}
	if ((fout=fopen(Scanout,"w"))==NULL)
	{
		printf("\n 创建词法分析输出文件出错！\n");
		return(2);
	}
	ch=getc(fin);
	while (ch!=EOF)
	{
		while (ch==''||ch=='\n'||ch=='\t') ch=getc(fin);
		if (isalpha(ch))
		{
			token[0]=ch;j=1;
			ch=getc(fin);
			while (isalnum(ch))

			{
				token [j++]=ch;
				ch=getc(fin);
			}
			token[j]='\0';
			//查保留字
			n=0;
			while ((n<keywordSum) && strcmp(token,keyword[n])) n++;
			if (n>=keywordSum)
				fprintf(fout,"%s\t%s\n","ID",token);
			else
				fprintf(fout,"%s\t%s\n",token,token) ;
		}
		else if (isdigit(ch))
		{
			token[0]=ch;j=1;
			ch=getc(fin);
			while(isdigit(ch))
			{
				token[j++]=ch;
				ch=getc(fin);
			}
			token[j]='\0'
			fprintf(fout,"%s\t%s\n","NUM",token) ;
		}
		else if (strchr(doubleword,ch)>0)
		{
			token[0]=ch;token[1]='\0';
			ch=getc(fin);
		}else				
			token[1]='\0';
			fprintf(fout,"%s\t%s\n",token,token);
		}
		else if (ch=='/')
	{
		ch=getc(fin);
		if (ch=='*')
		{
			char ch1;
			ch1=getc(fin);
			do
			{	
				ch=ch1;ch1=getc(fin);
			}
			while ((ch!='*'||ch1!='/')&&ch1!=EOF);

			ch=getc(fin);
		}
	}else
	{
		token[0]='/' ;token[1]='\0';
		fprintf(fout,"%s\t%s\n",token,token);
	}
}else
{
	token[0]=ch;token[1]='\0';
			ch=getc(fin);
			es=3;
			printf(fout,"%s\t%s\n", "ERROR",token);
		}
	}
	fclose(fin);
 	fclose(fout);
	return(es);




#include<stdio.h>
#include<ctype.h>
extern int TEST scan( );
char Scanin[300],Scanout[300] ;
FILE *fin,*fout;
void main( ){
	int es=0;
	es=TESTscan( ) ;
		if (es>0) printf(“词法分析有错，编译停止！") ;
	else printf (“词法分析成功！\n") ;
}