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

int main(int argc,char **argv) 
{ 
	char filename[128]="";
	
	strcpy(filename,argv[1]);
	printf("filename:%s\r\n",filename);
	
	FILE *fp = fopen(filename, "rb+"); 
	if (fp == NULL) 
	{
		printf("文件打开失败\n"); return -1; 
	} 
	int num_bytes = 10; // 要删除的字节数 
	fseek(fp, -num_bytes, SEEK_END); 
	ftruncate(fileno(fp), ftell(fp)); 
	fclose(fp); 
	return 0; 
}