单线程读fifo写文件

int log_fifo2file(char *fifoname, char *filename, size_t size, int expire, int *exitflag)
{
int             fd1, fd2;
size_t  nread, nwrite, sum;
char    file[PATH_MAX], filenew[PATH_MAX], tmp[16];
char    buffer[65536];
struct  pollfd  pfds[1];
int     nfds;
time_t  create, now;
struct  stat st;
struct  tm      tm;

if(fifoname == NULL || filename == NULL)
return EINVAL;
/* open fifo */
mkfifo(fifoname, 0644);
if(stat(fifoname, &st) != 0)
return errno;
if(!S_ISFIFO(st.st_mode))
return -1;
if((fd1 = open(fifoname, O_RDWR|O_NONBLOCK, 0)) < 0)
return errno;
pfds[0].fd = fd1;
pfds[0].events = POLLIN;
/* open file */
snprintf(file, sizeof(file), "%s.tmp", filename);
write:
if((fd2 = open(file, O_WRONLY|O_NONBLOCK|O_CREAT, 0644)) < 0)
return errno;
create = time(NULL);
sum = 0;
/* read fifo, write file */
while(!*exitflag){
nfds = poll(pfds, 1, 1000);
if(nfds <= 0)
goto check;
nread = read(fd1, buffer, sizeof(buffer));
if(nread < 0) continue;
if(nread == 0) break;
nwrite = write(fd2, buffer, nread);
if(nwrite < 0) continue;
sum += nwrite;
check:
now = time(NULL);
if((size > 0 && sum > size) || (expire > 0 && now > create + expire)){
close(fd2);
localtime_r(&now, &tm);
sprintf(tmp, "%04d%02d%02d%02d%02d%02d", tm.tm_year+1900, tm.tm_mon+1,tm.tm_mday, tm.tm_hour, tm.tm_min, tm .tm_sec);
snprintf(filenew, sizeof(filenew), "%s-%s.log", filename, tmp);
rename(file, filenew);
goto write;
}
}
close(fd1);
close(fd2);
now = time(NULL);
localtime_r(&now, &tm);
sprintf(tmp, "%04d%02d%02d%02d%02d%02d", tm.tm_year+1900, tm.tm_mon+1,tm.tm_mday, tm.tm_hour, tm.tm_min, tm .tm_sec);
snprintf(filenew, sizeof(filenew), "%s-%s.log", filename, tmp);
rename(file, filenew);
return 0;
}