top (Unix)

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top is a command in most Unix- like operating systems that outputs a continuously updated list of the system's currently running processes . Top also shows the load of the CPU , memory consumption and a lot of other information. Some versions of top can be configured very flexibly with regard to the information to be displayed.

The command is very useful for system administrators , among other things , as it gives an overview of which users and processes are putting the most stress on the system. For further processing by a script language or for recording, the output from top can also be redirected to a text file.

Compared to the command for one-time listing of processes,, psthe constant updating of top offers the advantage that the command does not have to be restarted constantly to stay up to date. In addition, top only shows as many processes as can fit in the terminal window. This means that (by default) only the most stressful processes are shown.

Development and variants

The development of top was inspired by the command of monitor process/topcputhe VMS operating system . William LeFebvre wrote the first implementation of top in April 1984 for BSD 4.1 as a student at Rice University . The project was published as open source under the very liberal BSD license , which is why the program quickly spread in various BSD variants and other Unix systems.

top has been redesigned several times from scratch for various operating systems and under different licenses. AIX version 4.3 included an enhanced version called topas . The first version for Linux was designed by Roger Binns in 1991, the newest and most widespread variant by James C. Warner supports other extensions in addition to a colored display of the process list.

Web links

Individual evidence

  1. William LeFebvre: Unix Top - information . Archived from the original on December 10, 2016. Info: The archive link was automatically inserted and not yet checked. Please check the original and archive link according to the instructions and then remove this notice. Retrieved February 13, 2017. @1@ 2Template: Webachiv / IABot /
  2. ^ Roger Binns: Top for Linux . 16 Sep 2014. Retrieved February 13, 2016.