Some useful ps commands switch combinations and examples are explained below:
1. ps aux & ps ax
These commands will print all process running on the system(server). aux displays more details like user, cpu, memory etc. with respect to ax.
# ps ax
# ps aux
2. Print processes like a tree format
# ps -ejH
# ps axjf
# pstree
3. Print security information
# ps -eo {euser, ruser, suser, fuser, comm, label}
# ps axZ
# ps -eM
This switch combination displays fue features like terminal, process ID, commands, time etc.. which are related to security.
4. Find out the top 10 memory consuming process on the system(server)
# ps -auxf | sort -nr -k 4 | head -10
5. Find out top 10 CPU consuming process
# ps -auxf | sort -nr -k 3 | head -10
6. Find out every process running under a user.
# ps -U user-name -u user-name u
7. Display only the process ID of a particular process under the system(server)
# ps -C PROCESS -o pid=
Or
# pgrep PROCESS
Or
# pgrep -u user-name PROCESS (running under the user)
8. PS command to displays the process name having a particular PID
# ps -p PID -o comm=
Additional information:
# ps -Al : Show Long Format Output.
# ps -AlF : To turn on extra full mode (it will show command line arguments passed to process).
# ps -AlFH : To See Threads ( LWP and NLWP).
# ps -AlLm : To See Threads After Processes.
# ps -e
# ps -ef
# ps -eF
# ps -ely
# -e Select all processes. Identical to -A.
# -f does full-format listing. This option can be combined with many other UNIX-style options to add additional columns. It also causes the command arguments to be printed. When used with -L, the NLWP (number of threads) and LWP (thread ID) columns will be added. See the c option, the format keyword args, and the format keyword comm.
# -F extra full format. See the -f option, which -F implies.
# -l long format. The -y option is often useful with this.
# -y Do not show flags; show rss in place of addr. This option can only be used with -l.