xref: /illumos-gate/usr/src/man/man3proc/proc_walk.3proc (revision b8052df9f609edb713f6828c9eecc3d7be19dfb3)
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12.\" Copyright 2019 Joyent, Inc.
13.\"
14.Dd December  2, 2019
15.Dt PROC_WALK 3PROC
16.Os
17.Sh NAME
18.Nm proc_walk
19.Nd walk all processes or threads in /proc
20.Sh SYNOPSIS
21.Lb libproc
22.In libproc.h
23.Ft int
24.Fo proc_walk
25.Fa "proc_walk_f *func"
26.Fa "void *arg"
27.Fa "int flag"
28.Fc
29.Sh DESCRIPTION
30The
31.Fn proc_walk
32function walks all threads and processes in /proc and calls the callback
33function
34.Fa func
35once for each one with the user specified
36.Fa arg .
37The definition of the
38.Sy proc_walk_f
39is available in
40.Xr libproc 3LIB .
41.Pp
42.Fa func
43will be called once for each process and will always have its first
44argument filled in with the value of the
45.Sy psinfo
46file of the process.
47The value of
48.Fa flag
49controls whether or not information about the threads in the process are
50included and how many times the callback function
51.Fa func
52is called.
53The following values may be passed in for
54.Fa flag :
55.Bl -tag -width Dv -offset indent
56.It Dv PR_WALK_PROC
57Indicates that the walker is only concerned with the process.
58.Fa func
59will be called once for each process in the system.
60Only the
61.Sy psinfo
62will be read for the process and passed to
63.Fa func .
64The second argument, the one for the
65.Sy lwpsinfo_t ,
66will be passed as
67.Dv NULL .
68.It Dv PR_WALK_LWP
69The caller wants both process and thread information.
70.Fa func
71will be called once for each thread in the system.
72In addition to the process
73.Sy psinfo
74information, the ps specific information for a given thread will be
75included in the
76.Fa lwpsinfo_t
77argument.
78.El
79.Pp
80In addition, the following values may be combined with one of the above
81values of
82.Fa flag
83with a bitwise-inclusive-OR:
84.Bl -tag -width Dv -offset indent
85.It Dv PR_WALK_INCLUDE_SYS
86Include
87.Sy SYS
88.Pq system
89processes.
90Normally
91.Sy SYS
92processes are skipped during the walk of the process tree.
93.El
94.Pp
95The return value of the caller's
96.Fa func
97function determines whether or not iteration will continue.
98If
99.Fa func
100returns a non-zero value, then iteration will terminate and that
101return value will be returned to the caller.
102To distinguish between system errors and caller errors, it is recommended that
103the function only return positive integers in the event of an error.
104.Sh RETURN VALUES
105Upon successful completion, the
106.Fn proc_walk
107function returns
108.Sy 0 .
109Otherwise,
110.Sy -1
111is returned and
112.Sy errno
113is updated to reflect the error that occurred.
114.Sh ERRORS
115In addition to the errors listed below, the
116.Fn proc_walk
117function may fail for the same reasons as the
118.Xr opendir 3C ,
119.Xr readdir 3C ,
120and
121.Xr malloc 3C
122functions.
123.Bl -tag -width Er
124.It Er EINVAL
125.Fa flag
126is not one of
127.Dv PR_WALK_PROC
128or
129.Dv PR_WALK_LWP .
130.El
131.Sh INTERFACE STABILITY
132.Sy Uncommitted
133.Sh MT-LEVEL
134.Sy MT-Safe
135.Sh SEE ALSO
136.Xr malloc 3C ,
137.Xr opendir 3C ,
138.Xr readdir 3C ,
139.Xr libproc 3LIB ,
140.Xr proc 5
141