Example--Listing Processes

The following example shows output from the ps command when no options are used.

$ ps
   PID TTY      TIME COMD
  1664 pts/4    0:06 csh
  2081 pts/4    0:00 ps

The following example shows output from ps -ef. This output shows that the first process that is executed when the system boots is sched (the swapper) followed by the init process, pageout, and so on.

$ ps -ef
     UID   PID  PPID  C    STIME TTY      TIME CMD
    root     0     0  0   Dec 20 ?        0:17 sched
    root     1     0  0   Dec 20 ?        0:00 /etc/init -
    root     2     0  0   Dec 20 ?        0:00 pageout
    root     3     0  0   Dec 20 ?        4:20 fsflush
    root   374   367  0   Dec 20 ?        0:00 /usr/lib/saf/ttymon
    root   367     1  0   Dec 20 ?        0:00 /usr/lib/saf/sac -t 300
    root   126     1  0   Dec 20 ?        0:00 /usr/sbin/rpcbind
    root    54     1  0   Dec 20 ?        0:00 /usr/lib/sysevent/syseventd
    root    59     1  0   Dec 20 ?        0:00 /usr/lib/picl/picld
    root   178     1  0   Dec 20 ?        0:03 /usr/lib/autofs/automountd
    root   129     1  0   Dec 20 ?        0:00 /usr/sbin/keyserv
    root   213     1  0   Dec 20 ?        0:00 /usr/lib/lpsched
    root   154     1  0   Dec 20 ?        0:00 /usr/sbin/inetd -s
    root   139     1  0   Dec 20 ?        0:00 /usr/lib/netsvc/yp/ypbind ...
    root   191     1  0   Dec 20 ?        0:00 /usr/sbin/syslogd
    root   208     1  0   Dec 20 ?        0:02 /usr/sbin/nscd
    root   193     1  0   Dec 20 ?        0:00 /usr/sbin/cron
    root   174     1  0   Dec 20 ?        0:00 /usr/lib/nfs/lockd
  daemon   175     1  0   Dec 20 ?        0:00 /usr/lib/nfs/statd
    root   376     1  0   Dec 20 ?        0:00 /usr/lib/ssh/sshd
    root   226     1  0   Dec 20 ?        0:00 /usr/lib/power/powerd
    root   315     1  0   Dec 20 ?        0:00 /usr/lib/nfs/mountd
    root   237     1  0   Dec 20 ?        0:00 /usr/lib/utmpd
    .
    .
    .    

The /proc File System and Commands

You can display detailed information about the processes listed in the /proc directory by using process commands. The /proc directory is also known as the process file system (PROCFS). Images of active processes are stored here by their process ID number.

The process tools are similar to some options of the ps command, except that the output that is provided by these commands is more detailed. In general, the process commands do the following:

• Display more information about processes, such as fstat and fcntl, working directories, and trees of parent and child processes

• Provide control over processes by allowing users to stop or resume them

Managing Processes With /proc Process Commands

You can display detailed, technical information about or control active processes by using some of the process commands. Table 23-3 lists some of the /proc commands.

If a process becomes trapped in an endless loop, or if it takes too long to execute, you might want to stop (kill) the process. For more information about stopping processes using the pkill command, see Chapter 23, Managing System Processes (Tasks).

The /proc file system is a directory hierarchy that contains additional subdirectories for state information and control functions.

The /proc file system also provides a watchpoint facility that is used to remap read and write permissions on the individual pages of a process's address space. This facility has no restrictions and is MT-safe.

Debugging tools have been modified to use /proc's watchpoint facility, which means that the entire watchpoint process is faster.

The following restrictions have been removed when setting watchpoints by using the dbx debugging tool:

• Setting watchpoints on local variables on the stack due to SPARC register windows

• Setting watchpoints on multithreaded processes

For more information, see proc(4), core(4), and mdb(1).

Table 23-3 /proc Process Commands

For more information, see proc(1).

How to Display Information About Processes

1. Obtain the process ID of the process you want to display more information about.

   # pgrep process

   
   

   process is the name of the process you want to display more information about.

   The process ID is displayed in the first column of the output.

2. Display the process information you need.

   # /usr/bin/pcommand pid

   
   

   pcommand	Process tool command that you want to run. Table 23-3 lists these commands.
   pid	Indicates the process ID.

Example--Displaying Information About Processes

The following example shows how to use process tool commands to display more information about an lpsched process.

# pgrep lpsched 1
213
# pwdx 213 2
213:    /
# ptree 213 3
213   /usr/lib/lpsched
# pfiles 213 4
213:    /usr/lib/lpsched
  Current rlimit: 4096 file descriptors
   0: S_IFIFO mode:0000 dev:270,0 ino:67 uid:0 gid:0 size:0
      O_RDWR
   1: S_IFIFO mode:0000 dev:270,0 ino:67 uid:0 gid:0 size:0
      O_RDWR
   3: S_IFCHR mode:0666 dev:136,0 ino:35882 uid:0 gid:3 rdev:21,0
      O_WRONLY FD_CLOEXEC
   4: S_IFDOOR mode:0444 dev:275,0 ino:18526 uid:0 gid:0 size:0
      O_RDONLY|O_LARGEFILE FD_CLOEXEC  door to nscd[208]
   5: S_IFREG mode:0664 dev:136,0 ino:64648 uid:71 gid:8 size:0
      O_WRONLY

1. Obtains the process identification number for lpsched

2. Displays the current working directory for lpsched

3. Displays the process tree that containslpsched

4. Displays fstat and fcntl information