xref: /illumos-gate/usr/src/man/man3proc/Pctlfd.3proc (revision 2a898b17c54fe53254413d8d4cac0de440289b59)
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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 SYNOPSIS
21.Lb libproc
22.In libproc.h
23.Ft int
24.Fo Pctlfd
25.Fa "struct ps_prochandle *P"
26.Fc
27.Sh DESCRIPTION
28The
29.Fn Pctlfd
30function returns a file descriptor to the underlying /proc file system
31.Sy ctl
32file for the process identified by the handle
33.Fa P .
34This may be used for injecting control operations manually;
35however, many interfaces for using it are provided by
36.Xr libproc 3LIB
37itself.
38.Pp
39Only live processes have a control file descriptor.
40Process handles that correspond to files and cores, created through
41.Xr Pgrab_file 3PROC
42and
43.Xr Pgrab_core 3PROC ,
44do not have a corresponding file descriptor.
45.Pp
46The file descriptor is invalidated when the process handle is released
47through
48.Xr Prelease 3PROC
49or if control is lost and the handle is reopened.
50.Sh RETURN VALUES
51Upon successful completion, the
52.Fn Pctlfd
53function returns a valid file descriptor.
54Otherwise, if none exists, then
55.Sy -1
56is returned.
57.Sh INTERFACE STABILITY
58.Sy Uncommitted
59.Sh MT-LEVEL
60See
61.Sy LOCKING
62in
63.Xr libproc 3LIB .
64.Sh SEE ALSO
65.Xr libproc 3LIB ,
66.Xr Pcreate 3PROC ,
67.Xr Pgrab 3PROC ,
68.Xr Pgrab_core 3PROC ,
69.Xr Pgrab_file 3PROC ,
70.Xr Prelease 3PROC ,
71.Xr Preopen 3PROC ,
72.Xr proc 4
73