Re: How to write a proper fork hook code?
On Sun, 2015-03-01 at 23:08 +0100, Svante Signell wrote:
> On Sun, 2015-03-01 at 22:06 +0100, Samuel Thibault wrote:
Much simpler code: It only opens a file and calls fork!
FCNTL_CALLS version triggers the hook
RPC_CALLS version does not
#define _GNU_SOURCE
#include <stdio.h>
#include <error.h>
#include <errno.h>
#include <unistd.h>
#include <sys/types.h>
#include <sys/wait.h>
#include <hurd.h>
#define FCNTL_CALLS
//#undef FCNTL_CALLS
//#undef RPC_CALLS
#define RPC_CALLS
int main (int argc, char **argv)
{
pid_t pid;
int status;
#ifdef FCNTL_CALLS
int fd1;
#endif
#ifdef RPC_CALLS
int fd2;
#endif
if (argc != 2)
error (1, 0, "Usage: %s file", argv[0]);
#ifdef FCNTL_CALLS
fd1 = open (argv[1], O_RDONLY | O_WRONLY | O_CREAT);
if (fd1 == -1)
error (1, errno, "fopen");
#endif
#ifdef RPC_CALLS
fd2 = file_name_lookup (argv[1], O_READ | O_WRITE | O_CREAT, 0666);
if (fd2 == MACH_PORT_NULL)
error (1, errno, "file_name_lookup");
#endif
printf ("Parent pid = %d\n", getpid());
pid = fork ();
if (pid == -1)
error (1, errno, "fork");
else if (pid == 0)
{
printf ("Child PID in the child = %d\n", pid);
exit(0);
}
else
{
printf ("Child PID in the parent = %d\n", pid);
waitpid(pid, &status, 0);
}
#ifdef FCNTL_CALLS
close (fd1);
#endif
#ifdef RPC_CALLS
mach_port_deallocate (mach_task_self (), fd2);
#endif
return 0;
}
Reply to: