使用inotify检测linux目录内文件变化

#include <unistd.h>
#include <sys/inotify.h>
#include <stdio.h>
#include <error.h>
#include <errno.h>
#include <string.h>

#define ERROR(text) error(1, errno, "%s", text)

typedef struct test{
int flag;
const char *name;
}EventMask;

int freadsome(void *dest, size_t remain, FILE *file)
{
char *offset = (char*)dest;
while (remain) {
int n = fread(offset, 1, remain, file);
if (n==0) {
return -1;
}
remain -= n;
offset += n;
}
return 0;
}

int main(int argc, char *argv[])
{
const char *target;
if (argc == 1) {
target = ".";
}
else {
target = argv[1];
}

EventMask event_masks[] = {
{IN_ACCESS        , "IN_ACCESS"}        ,
{IN_ATTRIB        , "IN_ATTRIB"}        ,
{IN_CLOSE_WRITE   , "IN_CLOSE_WRITE"}   ,
{IN_CLOSE_NOWRITE , "IN_CLOSE_NOWRITE"} ,
{IN_CREATE        , "IN_CREATE"}        ,
{IN_DELETE        , "IN_DELETE"}        ,
{IN_DELETE_SELF   , "IN_DELETE_SELF"}   ,
{IN_MODIFY        , "IN_MODIFY"}        ,
{IN_MOVE_SELF     , "IN_MOVE_SELF"}     ,
{IN_MOVED_FROM    , "IN_MOVED_FROM"}    ,
{IN_MOVED_TO      , "IN_MOVED_TO"}      ,
{IN_OPEN          , "IN_OPEN"}          ,

{IN_DONT_FOLLOW   , "IN_DONT_FOLLOW"}   ,
{IN_EXCL_UNLINK   , "IN_EXCL_UNLINK"}   ,
{IN_MASK_ADD      , "IN_MASK_ADD"}      ,
{IN_ONESHOT       , "IN_ONESHOT"}       ,
{IN_ONLYDIR       , "IN_ONLYDIR"}       ,

{IN_IGNORED       , "IN_IGNORED"}       ,
{IN_ISDIR         , "IN_ISDIR"}         ,
{IN_Q_OVERFLOW    , "IN_Q_OVERFLOW"}    ,
{IN_UNMOUNT       , "IN_UNMOUNT"}       ,
};

int monitor = inotify_init();
if ( -1 == monitor ) {
ERROR("monitor");
}

int watcher = inotify_add_watch(monitor, target, IN_ALL_EVENTS);
if ( -1 == watcher  ) {
ERROR("inotify_add_watch");
}

FILE *monitor_file = fdopen(monitor, "r");
char last_name[1024];
char name[1024];
/* event:inotify_event -> name:char[event.len] */

while (1) {

struct inotify_event event;
if ( -1 == freadsome(&event, sizeof(event), monitor_file) ) {
ERROR("freadsome");
}
if (event.len) {
freadsome(name, event.len, monitor_file);
} else {
sprintf(name, "FD: %d\n", event.wd);
}

if (strcmp(name, last_name) != 0) {
puts(name);
strcpy(last_name, name);
}

/* 显示event的mask的含义 */
int i = 0;
for (i=0; i<sizeof(event_masks)/sizeof(EventMask); ++i)
{
if (event.mask & event_masks[i].flag) {
printf("\t%s\n", event_masks[i].name);
}
}
}
return 0;
}