#include #include #include #include #include #include #include main(int argc, char *argv[]) { int result, fd; fd_set rset; char tmpstr[] = "seltest.XXXX"; if ((fd = mkstemp(tmpstr)) < 0) { printf ("Error %d opening temp file\n", errno); exit (-1); } lseek(fd, 0, SEEK_END); FD_ZERO(&rset); FD_SET(fd, &rset); result = select(fd + 1, &rset, 0, 0, 0); if (result == 1) printf("OK\n"); else printf("FAIL\n"); unlink(tmpstr); return !result; }