proc, pflags, pcred, pldd, psig, pstack, pfiles, pwdx,
pstop, prun, pwait, ptree, ptime - proc tools
/usr/bin/pflags [-r] [pid | core] ...
/usr/bin/pcred [pid | core] ...
/usr/bin/pldd [-F] [pid | core] ...
/usr/bin/psig [-n] pid...
/usr/bin/pstack [-F] [pid | core] ...
/usr/bin/pfiles [-F] pid...
/usr/bin/pwdx [-F] pid...
/usr/bin/pwait [-v] pid...
/usr/bin/ptree [-a] [pid | user] ...
/usr/bin/ptime command [arg...]
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.
Print the /proc tracing flags, the pending and held
signals, and other /proc status information for each
lwp in each process.
pcred Print 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(3DL). See also ldd(1).
psig List the signal actions and handlers of each process.
Print a hex+symbolic stack trace for each lwp in each
Report fstat(2) and fcntl(2) information for all open
files in each process.
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 precision. Unlike time(1),
children of the command are not timed.
The following options are supported:
-a (ptree only) All. Includes children of process 0.
-F Force. Grabs the target process even if another pro-
cess has control.
-n (psig only) Displays signal handler addresses rather
-r (pflags only) If the process is stopped, displays its
-v (pwait only) Verbose. Reports terminations to standard
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.
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 may 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 will be unavailable for display.
Similarly, 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) may
not be able to initialize. In this case, symbol information
for shared libraries will not be available.
The following exit values are returned:
0 Successful operation.
An error has occurred.
proc tools supporting files
See attributes(5) for descriptions of the following attri-
| ATTRIBUTE TYPE | ATTRIBUTE VALUE |
| Availability | SUNWesu (32-bit) |
| | SUNWesxu (64-bit) |
gcore(1), ldd(1), pargs(1), pgrep(1), pkill(1), plimit(1),
pmap(1), preap(1), ps(1), pwd(1), rlogin(1), time(1),
truss(1), wait(1), fcntl(2), fstat(2), dlopen(3DL),
signal(3HEAD), core(4), proc(4), attributes(5)
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.
Man(1) output converted with