pkill is a command-line utility initially written for use with the Solaris 7

Solaris Operating System

Solaris is a Unix operating system originally developed by Sun Microsystems. It superseded their earlier SunOS in 1993. Oracle Solaris, as it is now known, has been owned by Oracle Corporation since Oracle's acquisition of Sun in January 2010....

 operating system. It has since been reimplemented for Linux

Linux

Linux is a Unix-like computer operating system assembled under the model of free and open source software development and distribution. The defining component of any Linux system is the Linux kernel, an operating system kernel first released October 5, 1991 by Linus Torvalds...

 and some BSDs.

As with the kill

Kill (Unix)

In computing, kill is a command that is used in several popular operating systems to send signals to running processes, for example to request the termination of this process.-Unix and Unix-like:...

and killall

Killall

killall is a command line utility available on Unix-like systems. There are two very different implementations.* The implementation supplied with genuine UNIX System V and with the Linux [ftp://ftp.cistron.nl/pub/people/miquels/sysvinit/ sysvinit] tools is a particularly dangerous command that...

commands, pkill is used to send signals

Signal (computing)

A signal is a limited form of inter-process communication used in Unix, Unix-like, and other POSIX-compliant operating systems. Essentially it is an asynchronous notification sent to a process in order to notify it of an event that occurred. When a signal is sent to a process, the operating system...

 to 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...

. The pkill command allows the use of extended regular expression

Regular expression

In computing, a regular expression provides a concise and flexible means for "matching" strings of text, such as particular characters, words, or patterns of characters. Abbreviations for "regular expression" include "regex" and "regexp"...

 patterns and other matching criteria.

Example usage

Kill the most recently created acroread process

pkill -n acroread


Send a USR1 signal to acroread process:

pkill -USR1 acroread

See also

• List of Unix programs
• kill
  Kill (Unix)
  In computing, kill is a command that is used in several popular operating systems to send signals to running processes, for example to request the termination of this process.-Unix and Unix-like:...
  
  (1)
• nice
  Nice (Unix)
  nice is a program found on Unix and Unix-like operating systems such as Linux. nice directly maps to a kernel call of the same name. For a given process, it changes the priority in the kernel's scheduler. A niceness of −20 is the highest priority and 19 or 20 is the lowest priority...
  
  (1)
• skill(1), a command-line utility to send signals or report process status, pkill is favoured over it
• top(1), htop(1)