root@james-desktop:/mnt/buildroot-2011.11# make
>>> udev 173 Building
PATH="/mnt/buildroot-2011.11/output/host/bin:/mnt/buildroot-2011.11/output/host/usr/bin:/mnt/buildroot-2011.11/output/host/usr/sbin/:/opt/QtSDK/Desktop/Qt/474/gcc/bin:/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/games:/ct-ng-1.13.2/bin/" PERLLIB="/mnt/buildroot-2011.11/output/host/usr/lib/perl" /usr/bin/make -j2 -C /mnt/buildroot-2011.11/output/build/udev-173/
make[1]: 正在进入目录 `/mnt/buildroot-2011.11/output/build/udev-173'
/usr/bin/make --no-print-directory all-recursive
Making all in .
CC libudev/libudev-monitor.lo
CC libudev/libudev-queue.lo
libudev/libudev-monitor.c: In function 'udev_monitor_new_from_socket':
libudev/libudev-monitor.c:153: error: 'SOCK_NONBLOCK' undeclared (first use in this function)
libudev/libudev-monitor.c:153: error: (Each undeclared identifier is reported only once
libudev/libudev-monitor.c:153: error: for each function it appears in.)
libudev/libudev-monitor.c:153: error: 'SOCK_CLOEXEC' undeclared (first use in this function)
libudev/libudev-monitor.c: In function 'udev_monitor_new_from_netlink_fd':
libudev/libudev-monitor.c:186: error: 'SOCK_CLOEXEC' undeclared (first use in this function)
libudev/libudev-monitor.c:186: error: 'SOCK_NONBLOCK' undeclared (first use in this function)
http://blog.csdn.net/zjnig711/article/details/6148562
#if defined(SOCK_NONBLOCK)
return ::socket(AF_INET, SOCK_STREAM | SOCK_NONBLOCK, IPPROTO_TCP);
/* If they have O_NONBLOCK, use the Posix way to do it */
#elif defined(O_NONBLOCK)
/* Fixme: O_NONBLOCK is defined but broken on SunOS 4.1.x and AIX 3.2.5. */
int sock = socket(PF_INET, SOCK_STREAM, 0);
int flags;
if (-1 == (flags = fcntl(sock, F_GETFL, 0)))
flags = 0;
fcntl(sock, F_SETFL, flags | O_NONBLOCK);
return sock;
#else
int sock = socket(PF_INET, SOCK_STREAM, 0);
/* Otherwise, use the old way of doing it */
int flags = 1;
ioctl(sock, FIOBIO, &flags);
return sock;
#endif
http://kernel.org/doc/man-pages/online/pages/man2/socket.2.html
int socket(int domain, int type, int protocol);
Since Linux 2.6.27, the type argument serves a second purpose: in addition to specifying a socket type, it may include the bitwise OR of any of the following values, to modify the behavior of socket(): SOCK_NONBLOCK Set the O_NONBLOCK file status flag on the new open file description. Using this flag saves extra calls to fcntl(2) to achieve the same result. SOCK_CLOEXEC Set the close-on-exec (FD_CLOEXEC) flag on the new file descriptor. See the description of the O_CLOEXEC flag in open(2) for reasons why this may be useful.
2.6.27才有SOCK_NONBLOCK ,我们用的内核是Linux 2.6.22