Recipe: Gathering information about processes

ps
==
$ ps
  PID TTY          TIME CMD
 1220 pts/0    00:00:00 bash
 1242 pts/0    00:00:00 ps


$ ps -f
UID        PID  PPID  C STIME TTY          TIME CMD
slynux    1220  1219  0 18:18 pts/0    00:00:00 -bash
slynux    1587  1220  0 18:59 pts/0    00:00:00 ps -f


$ ps -e | head
  PID TTY          TIME CMD
    1 ?        00:00:00 init
    2 ?        00:00:00 kthreadd
    3 ?        00:00:00 migration/0
    4 ?        00:00:00 ksoftirqd/0
    5 ?        00:00:00 watchdog/0
    6 ?        00:00:00 events/0
    7 ?        00:00:00 cpuset
    8 ?        00:00:00 khelper
    9 ?        00:00:00 netns

ps - custom fields
==================
$ ps -eo comm,pcpu | head
COMMAND         %CPU
init             0.0
kthreadd         0.0
migration/0      0.0
ksoftirqd/0      0.0
watchdog/0       0.0
events/0         0.0
cpuset           0.0
khelper          0.0
netns            0.0

syntax:
=======
$ ps [OPTIONS] --sort -paramter1,+parameter2,parameter3..

Top 10 CPU consuming processes
==============================
$ ps -eo comm,pcpu --sort -pcpu | head
COMMAND         %CPU
Xorg             0.1
hald-addon-stor  0.0
ata/0            0.0
scsi_eh_0        0.0
gnome-settings-  0.0
init             0.0
hald             0.0
pulseaudio       0.0
gdm-simple-gree  0.0

Details of processes 'bash'
============================
$ ps -eo comm,pid,pcpu,pmem | grep bash
bash             1255  0.0  0.3
bash             1680  5.5  0.3

pgrep
=====
$ pgrep bash
1255
1680

Delimitor with pgrep
====================
$ pgrep COMMAND -d DELIMITER_STRING
$ pgrep bash -d “:”
1255:1680

Filter by users with pgrep
==========================
$ pgrep -u root,slynux COMMAND

Count matching processes
========================
$ pgrep -c COMMAND

Filter real and effective user on ps command
============================================
$ ps -u root -U root -o user,pcpu

Filter by TTY
=============
$ ps -t pts/0,pts/1
  PID TTY          TIME CMD
 1238 pts/0    00:00:00 bash
 1835 pts/1    00:00:00 bash
 1864 pts/0    00:00:00 ps


Display details of threads with ps
==================================
$ ps -eLf --sort -nlwp | head
UID        PID  PPID   LWP  C NLWP STIME TTY          TIME CMD
root       647     1   647  0   64 14:39 ?        00:00:00 /usr/sbin/console-kit-daemon --no-daemon
root       647     1   654  0   64 14:39 ?        00:00:00 /usr/sbin/console-kit-daemon --no-daemon
root       647     1   656  0   64 14:39 ?        00:00:00 /usr/sbin/console-kit-daemon --no-daemon
root       647     1   657  0   64 14:39 ?        00:00:00 /usr/sbin/console-kit-daemon --no-daemon
root       647     1   658  0   64 14:39 ?        00:00:00 /usr/sbin/console-kit-daemon --no-daemon
root       647     1   659  0   64 14:39 ?        00:00:00 /usr/sbin/console-kit-daemon --no-daemon
root       647     1   660  0   64 14:39 ?        00:00:00 /usr/sbin/console-kit-daemon --no-daemon
root       647     1   662  0   64 14:39 ?        00:00:00 /usr/sbin/console-kit-daemon --no-daemon
root       647     1   663  0   64 14:39 ?        00:00:00 /usr/sbin/console-kit-daemon --no-daemon

List environment variables associated with process
==================================================
$ ps -eo cmd e
$ ps -eo pid,cmd  e | tail -n 3
 1162 hald-addon-acpi: listening on acpid socket /var/run/acpid.socket
 1172 sshd: slynux [priv]
 1237 sshd: slynux@pts/0
 1238 -bash USER=slynux LOGNAME=slynux HOME=/home/slynux PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/games MAIL=/var/mail/slynux SHELL=/bin/bash SSH_CLIENT=10.211.55.2 49277 22 SSH_CONNECTION=10.211.55.2 49277 10.211.55.4 22 SSH_TTY=/dev/pts/0 TERM=xterm-color LANG=en_IN XDG_SESSION_COOKIE=d1e96f5cc8a7a3bc3a0a73e44c95121a-1286499339.592429-1573657095