daemon.man

.TP
\fB--pidfile\fR[\fB=\fIpidfile\fR]
Causes a file (by default, \fB\*(PN.pid\fR) to be created indicating
the PID of the running process.  If \fIpidfile\fR is not specified, or
if it does not begin with \fB/\fR, then it is created in
\fB@RUNDIR@\fR.

.TP
\fB--overwrite-pidfile\fR
By default, when \fB--pidfile\fR is specified and the specified pidfile 
already exists and is locked by a running process, \fB\*(PN\fR refuses 
to start.  Specify \fB--overwrite-pidfile\fR to cause it to instead 
overwrite the pidfile.

When \fB--pidfile\fR is not specified, this option has no effect.

.TP
\fB--detach\fR
Causes \fB\*(PN\fR to detach itself from the foreground session and
run as a background process.

.TP
\fB--no-chdir\fR
By default, when \fB--detach\fR is specified, \fB\*(PN\fR 
changes its current working directory to the root directory after it 
detaches.  Otherwise, invoking \fB\*(PN\fR from a carelessly chosen 
directory would prevent the administrator from unmounting the file 
system that holds that directory.
.IP
Specifying \fB--no-chdir\fR suppresses this behavior, preventing
\fB\*(PN\fR from changing its current working directory.  This may be 
useful for collecting core files, since it is common behavior to write 
core dumps into the current working directory and the root directory 
is not a good directory to use.
.IP
This option has no effect when \fB--detach\fR is not specified.