LinuxとFreeBSDの両方で利用できる、inotifyを使った実装を考える

     struct inotify_event {
         int         wd;       /* Watch descriptor */
         uint32_t    mask;     /* Mask of events */
         uint32_t    cookie;   /* Unique integer associating related events */
         uint32_t    len;      /* Size of name field */
         char        name[];   /* Optional null-terminated name */
     };

#include <stdio.h>
#include <string.h>
#include <unistd.h>
#include <poll.h>
#include <sys/inotify.h>
#ifdef __linux
#include <linux/limits.h>
#endif
#include <iostream>

int main( int argc, char **argv )
{
    int fd = -1;
    int wd = -1;
    if(argc<2){
        perror("error: please set directory");
        return 1;
    }
    char *dirname = argv[1];

    if( (fd = inotify_init()) == -1 ) {
        perror( "error: inotify_init" );
        return 1;
    }

    wd=inotify_add_watch(fd,dirname,IN_ATTRIB|IN_MODIFY|IN_CREATE|IN_DELETE|IN_MOVE);

    struct pollfd  spfd;
    spfd.fd=fd;
    spfd.events=POLLRDNORM;
    spfd.revents=0;

    int length = 0;

#ifdef __linux
    size_t szBuf=sizeof(struct inotify_event) + NAME_MAX + 1;
#else
    size_t szBuf=sizeof(struct inotify_event) + FILENAME_MAX + 1;
#endif
    char buf[szBuf];
    char* pc;
    struct inotify_event* pevent;
    size_t szPos=0;
    size_t szLen,szPacket;
    while(poll(&spfd,1,1000*10)>0){
        if( (szLen = read( fd, buf+szPos,  szBuf-szPos ) ) < 0 ) break;
        szPos+=szLen;
        while(szPos>=sizeof(struct inotify_event)){
                pevent=(struct inotify_event*)(buf);
                szPacket=sizeof(struct inotify_event)+pevent->len;
                if(szPos<szPacket) break;
                if(pevent->len>0) std::cout << "filename:" << pevent->name << " ";
                if(pevent->mask&IN_ATTRIB) std::cout << "IN_ATTRIB ";
                if(pevent->mask&IN_MODIFY) std::cout << "IN_MODIFY " ;
                if(pevent->mask&IN_CREATE) std::cout << "IN_CREATE ";
                if(pevent->mask&IN_DELETE) std::cout << "IN_DELETE ";
                if(pevent->mask&IN_MOVED_FROM) std::cout << "IN_MOVED_FROM ";
                if(pevent->mask&IN_MOVED_TO) std::cout << "IN_MOVED_TO";
                std::cout << std::endl;
                if(szPacket<szPos){
                        memcpy(buf,buf+szPacket,szPos-szPacket);
                        szPos-=szPacket;
                }else if(szPacket==szPos){
                        szPos=0;
                }
        }
    }

    inotify_rm_watch( fd, wd );
    close(fd);

    return 0;
}

$ ./inotify_sample .

$ touch test.txt
$ vi test.txt
$ rm test.txt

$ ./inotify_sample .
test.txt IN_CREATE
test.txt IN_MODIFY
test.txt IN_DELETE