test7_5.txt

linux under the C programming which complementary with the book of <linux under the C programming

#include <stdio.h>

int character;
char *token;

void lexicure(void);

int main(void)
{
    	lexicure();
    	while(character)
    	{
        	fprintf(stdout, token);
        	lexicure();
     	}
  
     	exit(0);
}


void lexicure(void)
{
    	character=getchar();
    	switch(character)
    	{
        	case 'A'...'Z': 
            		while((('A'<=character)&&('Z'>=character))|| (('0'<=character)&&('9'>=character)))
            		{
                		token+=character;
                		character=getchar();
            		}
            		if(character!=EOF)
				ungetc(character, stdin);
            		else
                		ungetc(0, stdin);
            		break;
        	case '0'...'9': 
            		while(('0'<=character)&&('9'>=character))
            		{
                		token+=character;
                		character=getchar();
            		}
            		if(character!=EOF)
				ungetc(character, stdin);
            		else
                		ungetc(0, stdin);
            		break;
	}
}