Linux redirect the stdout to a file
1: int save_out = dup(fileno(stdout));//backup stdout
2: int out = open("cout.log", O_RDWR|O_CREAT|O_APPEND, 0600);
3: int nRet;
4: fflush(stdout);
5: dup2(out, fileno(stdout));// redirect stdout to out
8: printf("Hello world!");
10: fflush(stdout);close(out);close(stdout);
11: dup2(save_out, fileno(stdout));//return the backup
12: close(save_out);
include the header file #include <fcntl.h>
