我有一个C程序,在其中使用遍历目录结构的递归函数。它接受一个toy_data.to_json()
'{"GDP_Quarterly_Growth_Rate":{"-710294400000":-0.266691,"-707616000000":-0.266691,"-704937600000":-0.266691,"-702345600000":-0.206496,"-699667200000":-0.206496,"-697075200000":-0.206496,"-694396800000":1.564208,"-691718400000":1.564208,"-689212800000":1.564208,"-686534400000":1.504256}}'
toy_data.resample('M', convention = 'start').mean()
变量,并从中创建一个gmtime结构。
递归dir函数来自How to recursively list directories in C on Linux?
time_t
这是运行程序时的输出。
void traversedir(time_t cutoff, const char* name, int indent)
{
if (indent > 9)
return;
DIR* dir;
struct dirent* entry;
if (!(dir = opendir(name)))
return;
struct tm *t = gmtime(&cutoff);
printf("%d-%d-%d %d:%d:%d (%lld)\n", (1900 + t->tm_year), (t->tm_mon + 1), t->tm_mday, t->tm_hour, t->tm_min, t->tm_sec, (long long) cutoff);
sleep(1); // only for debugging
while ((entry = readdir(dir)) != NULL) {
if (entry->d_type == DT_DIR) {
char path[1024];
if (entry->d_name[0] == '.' && !isValidNumber(entry->d_name))
continue;
snprintf(path, sizeof(path), "%s/%s", name, entry->d_name);
...
traversedir(cutoff, path, indent + 2);
}
}
closedir(dir);
}
void imageCleanup()
{
time_t cutoff = (time(NULL) - (86400 * 10));
do {
printf("Cutoff: %lld\n", (long long) cutoff);
traversedir(cutoff, "/path/to/dir", 0);
sleep(2);
cutoff += 3600;
} while (!available_storage() && cutoff < time(NULL));
}
从其转换结构的Cutoff: 1534245930
2018-8-14 11:25:30 (1534245930)
2018-8-24 11:25:31 (1534245930)
2018-8-14 11:25:30 (1534245930)
2018-8-24 11:25:33 (1534245930)
2018-8-14 11:25:30 (1534245930)
2018-8-14 11:25:35 (1534245930)
2018-8-14 11:25:30 (1534245930)
2018-8-14 11:25:30 (1534245930)
2018-8-24 11:25:38 (1534245930)
2018-8-14 11:25:30 (1534245930)
2018-8-14 11:25:30 (1534245930)
2018-8-14 11:25:30 (1534245930)
2018-8-14 11:25:30 (1534245930)
2018-8-24 11:25:43 (1534245930)
2018-8-14 11:25:30 (1534245930)
2018-8-14 11:25:30 (1534245930)
2018-8-14 11:25:30 (1534245930)
2018-8-14 11:25:30 (1534245930)
2018-8-14 11:25:30 (1534245930)
2018-8-14 11:25:30 (1534245930)
2018-8-14 11:25:30 (1534245930)
2018-8-14 11:25:30 (1534245930)
2018-8-24 11:25:52 (1534245930)
2018-8-14 11:25:30 (1534245930)
2018-8-24 11:25:54 (1534245930)
2018-8-14 11:25:55 (1534245930)
2018-8-24 11:25:56 (1534245930)
2018-8-14 11:25:30 (1534245930)
2018-8-24 11:25:58 (1534245930)
在括号中。始终为time_t
或2018年8月14日上午11:25:30,程序执行时为零十天。
您可以看到转换非常不一致。秒数次于执行时的实际时间。一天也要更改几次。
任何人都知道或有什么想法会导致这种情况?我已经尝试过制作一个简单的循环来转换静态1534245930
而没有任何问题,所以我只能假定它有一些东西要
答案 0 :(得分:2)
请注意,gmtime
不是reentrant,因为它返回某些静态数据的地址。您需要gmtime_r
(因为您的traversedir
函数是递归的),并且应该使用本地struct tm
automatic variable。
如此
struct tm mytm;
struct tm *t = gmtime_r(&cutoff, &mytm);
然后t
将指向call stack上的mytm
(而不是某些静态数据)。
您还应该使用strftime(3)(同样,将足够大的缓冲区声明为自动变量,或者使用一些堆分配的缓冲区)。