C语言getline循环读文件

#include <stdio.h>
#include <stdlib.h>
#include <string.h>

int main(int argc,const char *argv[])
{
    FILE *fp;
    size_t len = 0;
    char *buff = NULL;
     ssize_t read;
     
     if(argc != 2)
     {
         fprintf(stderr,"usage: %s <src>\n",argv[0]);
         exit(1);
     }
 
     if((fp=fopen(argv[1],"r")) == NULL)
     {
         perror("fopen()");
         exit(1);
     }
     
     while((read = getline(&buff,&len,fp)) != -1)
     {
      	printf("\n buff=0x%x \n", buff);
         //buff[read-1]='\0'; 去掉行末换行符
        fprintf(stdout," line: %s",buff);
     }
     fclose(fp);
 
     exit(0);
 }

输出：

$ ./c_getline_test.exx c_getline_test.c

 buff=0xc51d70
 line: #include <stdio.h>

 buff=0xc51d70
 line: #include <stdlib.h>

 buff=0xc51d70
 line: #include <string.h>

 buff=0xc51d70
&