ps - Examples and Simple Process Selection

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 To get security info: ps ‐eo euser,ruser,suser,fuser,f,comm,label ps axZ ps ‐eM To see every process running as root (real & effective ID) in user format: ps -U root -u root u To see every process with a user-defined format: ps -eo pid,tid,class,rtprio,ni,pri,psr,pcpu,stat,wchan:14,comm ps axo stat,euid,ruid,tty,tpgid,sess,pgrp,ppid,pid,pcpu,comm ps -Ao pid,tt,user,fname,tmout,f,wchan Print only the process IDs of syslogd: ps -C syslogd -o pid= Print only the name of PID 42: ps -q 42 -o comm= 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. -A Select all processes. Identical to -e. -a Select all processes except both session leaders (see getsid(2)) and processes not associated with a terminal. -d Select all processes except session leaders. --deselect Select all processes except those that fulfill the specified conditions (negates the selection). Identical to -N. -e Select all processes. Identical to -A. g Really all, even session leaders. This flag is obsolete and may be discontinued in a future release. It is normally implied by the a flag, and is only useful when operating in the sunos4 personality. -N Select all processes except those that fulfill the specified conditions (negates the selection). Identical to --deselect. T Select all processes associated with this terminal. Identical to the t option without any argument. r Restrict the selection to only running processes. 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. PROCESS SELECTION BY LIST These options accept a single argument in the form of a blank-separated or comma-separated list. They can be used multiple times. For example: ps -p "1 2" -p 3,4 -123 Identical to --pid 123. 123 Identical to --pid 123. -C cmdlist Select by command name. This selects the processes whose executable name is given in cmdlist. NOTE: The command name is not the same as the command line. Previous versions of procps and the kernel truncated this command name to 15 characters. This limitation is no longer present in

This section provides examples of how to use `ps` to view processes in different ways, including standard and BSD syntax, printing process trees, getting thread and security information, and using user-defined formats. It then details simple process selection options such as `-a`, `-A`, `-e`, `-d`, `-N`, `-T`, `-r`, and `-x`, which allow filtering processes based on terminal association, session leadership, running state, and BSD-style restrictions. Additionally, it covers process selection by list, allowing selection based on process ID or command name using options like `-C` and `-p`.