xref: /illumos-gate/usr/src/man/man3proc/Pctlfd.3proc (revision 45ede40b2394db7967e59f19288fae9b62efd4aa)
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12.\" Copyright 2015 Joyent, Inc.
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14.Dd May 11, 2016
15.Dt PCTFLD 3PROC
16.Os
17.Sh NAME
18.Nm Pctlfd
19.Nd obtain the process control file descriptor
20.Sh LIBRARY
21.Lb libproc
22.Sh SYNOPSIS
23.In libproc.h
24.Ft int
25.Fo Pctlfd
26.Fa "struct ps_prochandle *P"
27.Fc
28.Sh DESCRIPTION
29The
30.Fn Pctlfd
31function returns a file descriptor to the underlying /proc file system
32.Sy ctl
33file for the process identified by the handle
34.Fa P .
35This may be used for injecting control operations manually;
36however, many interfaces for using it are provided by
37.Xr libproc 3LIB
38itself.
39.Pp
40Only live processes have a control file descriptor.
41Process handles that correspond to files and cores, created through
42.Xr Pgrab_file 3PROC
43and
44.Xr Pgrab_core 3PROC ,
45do not have a corresponding file descriptor.
46.Pp
47The file descriptor is invalidated when the process handle is released
48through
49.Xr Prelease 3PROC
50or if control is lost and the handle is reopened.
51.Sh RETURN VALUES
52Upon successful completion, the
53.Fn Pctlfd
54function returns a valid file descriptor.
55Otherwise, if none exists, then
56.Sy -1
57is returned.
58.Sh INTERFACE STABILITY
59.Sy Uncommitted
60.Sh MT-LEVEL
61See
62.Sy LOCKING
63in
64.Xr libproc 3LIB .
65.Sh SEE ALSO
66.Xr libproc 3LIB ,
67.Xr Pcreate 3PROC ,
68.Xr Pgrab 3PROC ,
69.Xr Pgrab_core 3PROC ,
70.Xr Pgrab_file 3PROC ,
71.Xr Prelease 3PROC ,
72.Xr Preopen 3PROC ,
73.Xr proc 4
74