Pctlfd —
obtain the process control file descriptor
Process Control Library (libproc, -lproc)
#include
<libproc.h>
int
Pctlfd(
struct
ps_prochandle *P);
The
Pctlfd() function returns a file
descriptor to the underlying /proc file system
ctl file for the process identified by the handle
P. This may be used for injecting control
operations manually; however, many interfaces for using it are provided by
libproc(3LIB) itself.
Only live processes have a control file descriptor. Process handles that
correspond to files and cores, created through
Pgrab_file(3PROC) and
Pgrab_core(3PROC), do not have a corresponding
file descriptor.
The file descriptor is invalidated when the process handle is released through
Prelease(3PROC) or if control is lost and the
handle is reopened.
Upon successful completion, the
Pctlfd()
function returns a valid file descriptor. Otherwise, if none exists, then
-1 is returned.
Uncommitted
See
LOCKING in
libproc(3LIB).
libproc(3LIB),
Pcreate(3PROC),
Pgrab(3PROC),
Pgrab_core(3PROC),
Pgrab_file(3PROC),
Prelease(3PROC),
Preopen(3PROC),
proc(4)