report a snapshot of the current processes.
$ ps --help Usage: ps [options] Try 'ps --help <simple|list|output|threads|misc|all>' or 'ps --help <s|l|o|t|m|a>' for additional help text. For more details see ps(1).
$ ps --help simple Usage: ps [options] Basic options: -A, -e all processes -a all with tty, except session leaders a all with tty, including other users -d all except session leaders -N, --deselect negate selection r only running processes T all processes on this terminal x processes without controlling ttys For more details see ps(1).
# man ps
EXAMPLES
To see every process on the system using standard syntax:
ps -e
ps -ef
ps -eF
ps -ely
To see every process on the system using BSD syntax:
ps ax
ps axu
To print a process tree:
ps -ejH
ps axjf
To get info about threads:
ps -eLf
ps axms
SIMPLE PROCESS SELECTION
a Lift the BSD-style "only yourself" restriction, which is imposed upon the set of all processes when some
BSD-style (without "-") options are used or when the ps personality setting is BSD-like. The set of
processes selected in this manner is in addition to the set of processes selected by other means. An
alternate description is that this option causes ps to list all processes with a terminal (tty), or to
list all processes when used together with the x option.
x Lift the BSD-style "must have a tty" restriction, which is imposed upon the set of all processes when
some BSD-style (without "-") options are used or when the ps personality setting is BSD-like. The set of
processes selected in this manner is in addition to the set of processes selected by other means. An
alternate description is that this option causes ps to list all processes owned by you (same EUID as ps),
or to list all processes when used together with the a option.
OUTPUT FORMAT CONTROL
u Display user-oriented format.
l Display BSD long format.
OUTPUT MODIFIERS
f ASCII art process hierarchy (forest).
w Wide output. Use this option twice for unlimited width.
[root@localhost ~]# ps -ef UID PID PPID C STIME TTY TIME CMD root 1 0 0 00:01 ? 00:00:00 init [3] root 2 1 0 00:01 ? 00:00:00 [migration/0] root 3 1 0 00:01 ? 00:00:00 [ksoftirqd/0] (abbr)
You can check %CPU and %MEM.
[root@localhost ~]# ps aux USER PID %CPU %MEM VSZ RSS TTY STAT START TIME COMMAND root 1 0.3 0.0 10348 688 ? Ss 00:01 0:00 init [3] root 2 0.0 0.0 0 0 ? S< 00:01 0:00 [migration/0] root 3 0.0 0.0 0 0 ? SN 00:01 0:00 [ksoftirqd/0] (abbr)
[root@localhost ~]# ps alx F UID PID PPID PRI NI VSZ RSS WCHAN STAT TTY TIME COMMAND 4 0 1 0 15 0 10348 684 - Ss ? 0:00 init [3] 1 0 2 1 -100 - 0 0 migrat S< ? 0:00 [migration/0] 1 0 3 1 34 19 0 0 ksofti SN ? 0:00 [ksoftirqd/0] (abbr)
[root@localhost ~]# ps auxf USER PID %CPU %MEM VSZ RSS TTY STAT START TIME COMMAND (abbr) root 319 0.2 0.1 10868 956 ? S<s 00:08 0:00 /sbin/udevd -d root 1102 0.0 0.1 10864 944 ? S< 00:08 0:00 \_ /sbin/udevd -d root 1103 0.0 0.1 10864 944 ? S< 00:08 0:00 \_ /sbin/udevd -d (abbr) root 1120 0.4 0.8 100364 4168 ? Ss 00:09 0:00 \_ sshd: root@pts/0 root 1122 0.2 0.3 108304 1900 pts/0 Ss 00:09 0:00 \_ -bash root 1137 0.0 0.2 110336 1144 pts/0 R+ 00:09 0:00 \_ ps auxf (abbr) root 1042 0.0 0.8 183796 4236 ? Ss 00:08 0:00 /usr/sbin/httpd apache 1048 0.0 1.0 185448 5300 ? S 00:08 0:00 \_ /usr/sbin/httpd apache 1049 0.0 1.0 185448 5300 ? S 00:08 0:00 \_ /usr/sbin/httpd apache 1050 0.0 1.0 185448 5300 ? S 00:08 0:00 \_ /usr/sbin/httpd apache 1051 0.0 1.0 185448 5300 ? S 00:08 0:00 \_ /usr/sbin/httpd apache 1052 0.0 1.0 185448 5300 ? S 00:08 0:00 \_ /usr/sbin/httpd apache 1053 0.0 1.0 185448 5300 ? S 00:08 0:00 \_ /usr/sbin/httpd apache 1054 0.0 1.0 185448 5300 ? S 00:08 0:00 \_ /usr/sbin/httpd apache 1055 0.0 1.0 185448 5300 ? S 00:08 0:00 \_ /usr/sbin/httpd (abbr)
ps auwwx --sort=-rss ps -C httpd -o pid,pmem,sz,rss,vsz,comm --sort -rss ps auxw -L --sort=-vsz > /tmp/ps.`date +%Y%m%d%k%M%S`
ps auwwx --sort=-pcpu
ps -C httpd | wc -l
ps auxw | grep mysql | grep -v grep | wc -l
ps -C httpd -L |wc -l ← -L with thred
# ps aux USER PID %CPU %MEM VSZ RSS TTY STAT START TIME COMMAND root 1 0.3 0.0 10348 688 ? Ss 00:01 0:00 init [3] root 2 0.0 0.0 0 0 ? S< 00:01 0:00 [migration/0]
| Article | Explanation |
|---|---|
| USER | |
| PID | |
| %CPU | cpu utilization of the process |
| %MEM | ratio of the process's resident set size to the physical memory on the machine, expressed as a percentage. |
| VSZ | virtual memory size of the process in KiB When the process is started, the memory size to be secured. |
| RSS | resident set size, the non-swapped physical memory that a task has used (in kiloBytes). In the VSZ, size that occupied the physical memory actually If the swap-out has occurred, I will check whether there is a process size of RSS is extremely large. |
| TTY | |
| STAT | |
| START | |
| TIME | |
| COMMAND |