经常有这样一种需求，希望有些设置的信息（比如说账号信息）能够掉电后不丢失，重新开机后能够重新读出来。最简单的做法是把信息保存在文件中，文件在nand flash上就不会掉电丢失。
我们不仅可以向文件中写字符串，其实写结构体也是可以的。注意结构体里面不能有指针。
假设我们要保存一个账号结构体到文件，
#include <stdio.h>
#include <errno.h>
#include <string.h>
typedef struct _Account{
char usrname[128];
char passwd[128];
int age;
int level;
}Account;
void write_account2file(const char *path, Account *account)
{
FILE *fp = NULL;
fp = fopen(path, "w+");
if (NULL == fp)
{
printf("open %s fail, errno: %d", path, errno);
return;
}
fwrite(account, sizeof(Account), 1, fp);
fclose(fp);
return;
}
void read_accountFromFile(const char *path, Account *account)
{
FILE *fp = fopen(path, "r");
if (NULL == fp)
{
printf("open %s fail, errno: %d", path, errno);
return;
}
fread(account, sizeof(Account), 1, fp);
fclose(fp);
}
void main(void)
{
#if 0
Account account;
strncpy(account.usrname, "fellow", strlen("fellow"));
account.usrname[strlen("fellow")] = ' ';
strncpy(account.passwd, "1111", strlen("1111"));
account.passwd[strlen("1111")] = ' ';
account.age = 18;
account.level = 0;
write_account2file("/mnt/hgfs/share/test/account.txt", &account);
#endif
Account read;
read_accountFromFile("/mnt/hgfs/share/test/account.txt", &read);
printf("read:%s,%s,%d,%d
", read.usrname, read.passwd, read.age,read.level);
}
执行结果如下：
