* Use setsid instead of setpgrp in child processes. This not only

creates a new process group but also a new session.  New sessions
  have no controlling tty, so child processes like ssh cannot open
  /dev/tty (which is bad).
This commit is contained in:
Eelco Dolstra 2006-02-03 14:20:59 +00:00
parent b90daaaf6c
commit 81de538e46
1 changed files with 8 additions and 6 deletions

View File

@ -276,17 +276,19 @@ void Goal::trace(const format & f)
/* Common initialisation performed in child processes. */
void commonChildInit(Pipe & logPipe)
{
/* Put the child in a separate process group so that it doesn't
receive terminal signals. */
if (setpgid(0, 0) == -1)
throw SysError(format("setting process group"));
/* Put the child in a separate session (and thus a separate
process group) so that it has no controlling terminal (meaning
that e.g. ssh cannot open /dev/tty) and it doesn't receive
terminal signals. */
if (setsid() == -1)
throw SysError(format("creating a new session"));
/* Dup the write side of the logger pipe into stderr. */
if (dup2(logPipe.writeSide, STDERR_FILENO) == -1)
throw SysError("cannot pipe standard error into log file");
logPipe.readSide.close();
/* Dup stderr to stdin. */
/* Dup stderr to stdout. */
if (dup2(STDERR_FILENO, STDOUT_FILENO) == -1)
throw SysError("cannot dup stderr into stdout");