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;
}