[buug] Linux hacking question
itz at speakeasy.org
Fri May 31 23:43:48 PDT 2002
Hi, how can I get the ID of the foreground process group for a
terminal? Assume I am running with root privileges, but the terminal
is _not_ my controlling terminal (in fact I am a daemon, so I have no
controlling terminal). I tried
ioctl(terminal_fd, TIOCGPGRP, &foreground);
but it fails with ENOTTY, and in linux/drivers/char/tty_io.c I find
tiocgpgrp(struct tty_struct *tty, struct tty_struct *real_tty, pid_t *arg)
* (tty == real_tty) is a cheap way of
* testing if the tty is NOT a master pty.
if (tty == real_tty && current->tty != real_tty)
return put_user(real_tty->pgrp, arg);
so it's clear it that it fails in my case, root or not.
Ian Zimmerman, Oakland, California, U.S.A.
GPG: 433BA087 9C0F 194F 203A 63F7 B1B8 6E5A 8CA3 27DB 433B A087
EngSoc adopts market economy: cheap is wasteful, efficient is expensive.
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