LDD3 scullp.ko与测试程序问题

Question

#include <stdio.h> #include <stdlib.h> #include <string.h> #include <errno.h> #include <unistd.h> #include <fcntl.h> #include <sys/types.h> int main(int argc,char** argv) { char *buf=malloc(atoi(argv[2])); int fn,n; if(argc!=3)         exit(1); if((fn=open(argv[1],O_RDWR))==-1){         printf("openfilenew:open file %sfailure because %s\n",argv[1],strerror(errno));         exit(1); } n=read(fn,buf,atoi(argv[2])); if(n=-1){         printf("openfilenew:read file %s failure because %s \n",argv[1],strerror(errno));         close(fn);         exit(1); } printf("openfilenew:we read %i bytes =%s\n",n,buf); close(fn); return 0; }

Answer 1

自己搞错了
if(n=-1)-------------------------if(n==-1)

Answer 2

Answer 3

Answer 4

低级错误啊

Answer 5

代码多的话，这样的错误还不好检查呢
所以有个好习惯很重要

Answer 6

尽量这样写代码：
if(－1 ＝＝ n)
笔误的话编译不过，代码风格也很重要啊

Answer 7

谢了!牢记!