User Commands proc(1)
NAME
proc, pflags, pcred, pldd, psig, pstack, pfiles, pwdx,
pstop, prun, pwait, ptree, ptime - proc tools
SYNOPSIS
/usr/bin/pflags [-r] pid | core [/lwp] ...
/usr/bin/pcred [pid | core] ...
/usr/bin/pcred [-u user/uid] [-g group/gid] [-G grouplist]
pid...
/usr/bin/pcred -l login pid...
/usr/bin/pldd [-F] [pid | core] ...
/usr/bin/psig [-n] pid ...
/usr/bin/pstack [-F] pid | core [/lwp] ...
/usr/bin/pfiles [-Fn] pid...
/usr/bin/pwdx pid...
/usr/bin/pstop pid...
/usr/bin/prun pid...
/usr/bin/pwait [-v] pid...
/usr/bin/ptree [-a] [-c] [-z zone] [pid | user] ...
/usr/bin/ptime command [arg...]
DESCRIPTION
The proc tools are utilities that exercise features of /proc
(see proc(4)). Most of them take a list of process-ids
(pid). The tools that do take process-ids also accept
/proc/nnn as a process-id, so the shell expansion /proc/*
can be used to specify all processes in the system.
Some of the proc tools can also be applied to core files
(see core(4)). The tools that apply to core files accept a
list of either process IDs or names of core files or both.
Some of the proc tools can operate on individual threads.
Users can examine only selected threads by appending
/thread-id to the process-id or core. Multiple threads can
be selected using the - and , delimiters. For example
/1,2,7-9 examines threads 1, 2, 7, 8, and 9.
See WARNINGS.
pflags Print the /proc tracing flags, the pending
and held signals, and other /proc status
information for each lwp in each process.
pcred Print or set the credentials (effective,
real, saved UIDs and GIDs) of each process.
pldd List the dynamic libraries linked into each
process, including shared objects explicitly
attached using dlopen(3C). See also ldd(1).
psig List the signal actions and handlers of each
process. See signal.h(3HEAD).
pstack Print a hex+symbolic stack trace for each
lwp in each process.
pfiles Report fstat(2) and fcntl(2) information for
all open files in each process. In addition,
a path to the file is reported if the infor-
mation is available from /proc/pid/path.
This is not necessarily the same name used
to open the file. See proc(4) for more
information.
pwdx Print the current working directory of each
process.
pstop Stop each process (PR_REQUESTED stop).
prun Set each process running (inverse of pstop).
pwait Wait for all of the specified processes to
terminate.
ptree Print the process trees containing the
specified pids or users, with child
processes indented from their respective
parent processes. An argument of all digits
is taken to be a process-id, otherwise it is
assumed to be a user login name. Default is
all processes.
ptime Time the command, like time(1), but using
microstate accounting for reproducible pre-
cision. Unlike time(1), children of the com-
mand are not timed.
OPTIONS
The following options are supported:
-a (ptree only) All. Includes children of process 0.
-c (ptree only). Contracts. Show process contract
memberships in addition to parent-child relation-
ships. See process(4). Implies -a.
-F Force. Grabs the target process even if another
process has control.
-n (psig and pfiles only) Sets non-verbose mode. psig
displays signal handler addresses rather than
names. pfiles does not display verbose information
for each file descriptor. Instead, pfiles limits
its output to the information that would be
retrieved if the process applied fstat(2) to each
of its file descriptors.
-r (pflags only) If the process is stopped, displays
its machine registers.
-v (pwait only) Verbose. Reports terminations to stan-
dard output.
-z zone (ptree only) Prints only processes in the specified
zone. Each zone ID can be specified as either a
zone name or a numerical zone ID. This option is
only useful when executed in the global zone.
Additionally, pcred supports the following options:
-g group/gid Sets the real, effective, and saved group
ids (GIDs) of the target processes to the
specified value.
-G grouplist Sets the supplementary GIDs of the target
process to the specified list of groups. The
supplementary groups should be specified as
a comma-separated list of group names ids.
An empty list clears the supplementary group
list of the target processes.
-l login Sets the real, effective, and saved UIDs of
the target processes to the UID of the
specified login. Sets the real, effective,
and saved GIDs of the target processes to
the GID of the specified login. Sets the
supplementary group list to the supplemen-
tary groups list of the specified login.
-u user/uid Sets the real, effective, and saved user ids
(UIDs) of the target processes to the speci-
fied value.
In order to set the credentials of another process, a pro-
cess must have sufficient privilege to change its user and
group ids to those specified according to the rules laid out
in setuid(2) and it must have sufficient privilege to con-
trol the target process.
USAGE
These proc tools stop their target processes while inspect-
ing them and reporting the results: pfiles, pldd, and
pstack. A process can do nothing while it is stopped. Thus,
for example, if the X server is inspected by one of these
proc tools running in a window under the X server's control,
the whole window system can become deadlocked because the
proc tool would be attempting to print its results to a win-
dow that cannot be refreshed. Logging in from from another
system using rlogin(1) and killing the offending proc tool
would clear up the deadlock in this case.
See WARNINGS.
Caution should be exercised when using the -F flag. Imposing
two controlling processes on one victim process can lead to
chaos. Safety is assured only if the primary controlling
process, typically a debugger, has stopped the victim pro-
cess and the primary controlling process is doing nothing at
the moment of application of the proc tool in question.
Some of the proc tools can also be applied to core files, as
shown by the synopsis above. A core file is a snapshot of a
process's state and is produced by the kernel prior to ter-
minating a process with a signal or by the gcore(1) utility.
Some of the proc tools can need to derive the name of the
executable corresponding to the process which dumped core or
the names of shared libraries associated with the process.
These files are needed, for example, to provide symbol table
information for pstack(1). If the proc tool in question is
unable to locate the needed executable or shared library,
some symbol information is unavailable for display. Simi-
larly, if a core file from one operating system release is
examined on a different operating system release, the run-
time link-editor debugging interface (librtld_db) cannot be
able to initialize. In this case, symbol information for
shared libraries is not available.
EXIT STATUS
The following exit values are returned:
0 Successful operation.
non-zero An error has occurred.
FILES
/proc/* process files
ATTRIBUTES
See attributes(5) for descriptions of the following attri-
butes:
____________________________________________________________
| ATTRIBUTE TYPE | ATTRIBUTE VALUE |
|_____________________________|_____________________________|
| Availability | SUNWesu |
|_____________________________|_____________________________|
| Interface Stability | See below. |
|_____________________________|_____________________________|
Human Readable Output is Unstable. Options are Evolving.
SEE ALSO
gcore(1), ldd(1), pargs(1), pgrep(1), pkill(1), plimit(1),
pmap(1), preap(1), ps(1), ppgsz(1), pwd(1), rlogin(1),
time(1), truss(1), wait(1), fcntl(2), fstat(2), setuid(2),
dlopen(3C), signal.h(3HEAD), core(4), proc(4), process(4),
attributes(5), zones(5)
WARNINGS
The following proc tools stop their target processes while
inspecting them and reporting the results: pfiles, pldd,
pmap, and pstack.
A process can do nothing while it is stopped. Stopping a
heavily used process in a production environment, even for a
short amount of time, can cause severe bottlenecks and even
hangs of these processes, causing them to be unavailable to
users. Some databases could also terminate abnormally. Thus,
for example, a database server under heavy load could hang
when one of the database processes is traced using the above
mentioned proc tools. Because of this, stopping a UNIX pro-
cess in a production environment should be avoided.
A process being stopped by these tools can be identified by
issuing /usr/bin/ps -eflL and looking for "T" in the first
column. Notice that certain processes, for example "sched",
can show the "T" status by default most of the time.
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