[hackers] [ubase] Error out if dup2 doesn't return the fd we want || sin

[git]

commit f308a587400f29391626fe7243256c918cfd120a
Author: sin <s...@2f30.org>
Date:   Thu Apr 10 11:21:12 2014 +0100

    Error out if dup2 doesn't return the fd we want

diff --git a/getty.c b/getty.c
index 73f918d..3a580ad 100644
--- a/getty.c
+++ b/getty.c
@@ -65,9 +65,12 @@ main(int argc, char *argv[])
        fd = open(tty, O_RDWR);
        if (fd < 0)
                eprintf("open %s:", tty);
-       dup2(fd, STDIN_FILENO);
-       dup2(fd, STDOUT_FILENO);
-       dup2(fd, STDERR_FILENO);
+       if (dup2(fd, STDIN_FILENO) != STDIN_FILENO)
+               eprintf("dup2:");
+       if (dup2(fd, STDOUT_FILENO) != STDOUT_FILENO)
+               eprintf("dup2:");
+       if (dup2(fd, STDERR_FILENO) != STDERR_FILENO)
+               eprintf("dup2:");
 
        sa.sa_handler = SIG_DFL;
        sa.sa_flags = 0;