A Unix-like operating system is one that behaves in a manner similar to a Unix system, while not necessarily conforming to or being certified to any version of the Single UNIX Specification....
operating systems, the ps program (short for "process status") displays the currently-running processes
Process (computing)
In computing, a process is an instance of a computer program that is being executed. It contains the program code and its current activity. Depending on the operating system , a process may be made up of multiple threads of execution that execute instructions concurrently.A computer program is a...
top is a program found in many Unix-like operating systems. It produces an ordered list of running processes selected by user-specified criteria, and updates it periodically. Default ordering by CPU usage, and only the top CPU consumers shown top shows how much processing power and memory are...
provides a real-time view of the running processes.
Microsoft Windows is a series of operating systems produced by Microsoft.Microsoft introduced an operating environment named Windows on November 20, 1985 as an add-on to MS-DOS in response to the growing interest in graphical user interfaces . Microsoft Windows came to dominate the world's personal...
Windows PowerShell is Microsoft's task automation framework, consisting of a command-line shell and associated scripting language built on top of, and integrated with the .NET Framework...
, ps is a predefined command alias for the Get-Process cmdlet which basically serves the same purpose.
Examples
For example:
PID TTY TIME CMD
7431 pts/0 00:00:00 su
7434 pts/0 00:00:00 bash
18585 pts/0 00:00:00 ps
Users can also utilize the ps command in conjunction with the grep
Grep
grep is a command-line text-search utility originally written for Unix. The name comes from the ed command g/re/p...
pgrep is a command-line utility initially written for use with the Solaris 7 operating system. It has since been reimplemented for Linux and the BSDs . It searches for all the named processes that can be specified as extended regular expression patterns, and—by default—returns their process ID...
pkill is a command-line utility initially written for use with the Solaris 7 operating system. It has since been reimplemented for Linux and some BSDs.As with the kill and killall commands, pkill is used to send signals to processes...
commands) command to find information about one process, such as its process id:
$ # Trying to find the PID of `firefox-bin` which is 2701
$ ps -A | grep firefox-bin
2701 ? 22:16:04 firefox-bin
pgrep is a command-line utility initially written for use with the Solaris 7 operating system. It has since been reimplemented for Linux and the BSDs . It searches for all the named processes that can be specified as extended regular expression patterns, and—by default—returns their process ID...
:
$ pgrep -l firefox-bin
2701 firefox-bin
To see every process running as root (real & effective ID) in user format:
ps -U root -u root u
USER PID %CPU %MEM VSZ RSS TTY STAT START TIME COMMAND
root 1 0.0 0.0 10348 640 ? Ss 2009 0:06 init [5]
An operating system is a set of programs that manage computer hardware resources and provide common services for application software. The operating system is the most important type of system software in a computer system...
POSIX , an acronym for "Portable Operating System Interface", is a family of standards specified by the IEEE for maintaining compatibility between operating systems...
standards, ps commonly runs with the options -ef, where "-e" selects every process and "-f" chooses the "full" output format. Another common option on these systems is -l, which specifies the "long" output format.
Most systems derived from BSD fail to accept the SUS and POSIX standard options because of historical conflicts
(for example, the "e" or "-e" option will cause the display of environment variable
Environment variable
Environment variables are a set of dynamic named values that can affect the way running processes will behave on a computer.They can be said in some sense to create the operating environment in which a process runs...
s).
On such systems, ps commonly runs with the non-standard options aux, where "a" lists all processes on a terminal
Computer terminal
A computer terminal is an electronic or electromechanical hardware device that is used for entering data into, and displaying data from, a computer or a computing system...
, including those of other users, "x" lists all processes without controlling terminals and "u" adds a column for the controlling user for each process. Note that, for maximum compatibility when using this syntax, there is no "-" in front of the "aux". Also you can add 'ww' after aux, like "ps auxww" for complete information about the process including all parameters.
nmon is a popular system monitor tool for the AIX and Linux operating systems.- Description :The original nmon was a freely downloadable tool for AIX 4.3 from the AIX wiki. It was also rewritten for the Linux operating system running on IA-32, x86-64, RS/6000 and Power processor and Mainframe and...
— a system monitor tool for the AIX and Linux operating systems.
pgrep is a command-line utility initially written for use with the Solaris 7 operating system. It has since been reimplemented for Linux and the BSDs . It searches for all the named processes that can be specified as extended regular expression patterns, and—by default—returns their process ID...
pstree is a Unix command that shows the running processes as a tree. It is used as a more visual alternative to the ps command. The root of the tree is either init or the process with the given pid.-See also:*top*ps*kill*nice*tree-External links:...
top is a program found in many Unix-like operating systems. It produces an ordered list of running processes selected by user-specified criteria, and updates it periodically. Default ordering by CPU usage, and only the top CPU consumers shown top shows how much processing power and memory are...
External links
ps — Specification from the Single Unix Specification
