Ptx (Unix)
Template:Short description Template:Refimprove Template:Lowercase {{#invoke:Infobox|infobox}}Template:Template other{{#invoke:Check for unknown parameters | check | showblankpositional=1 | unknown = Template:Main other | preview = Page using Template:Infobox software with unknown parameter "_VALUE_"|ignoreblank=y | AsOf | author | background | bodystyle | caption | collapsetext | collapsible | developer | discontinued | engine | engines | genre | included with | language | language count | language footnote | latest preview date | latest preview version | latest release date | latest release version | latest_preview_date | latest_preview_version | latest_release_date | latest_release_version | licence | license | logo | logo alt | logo caption | logo upright | logo size | logo title | logo_alt | logo_caption | logo_upright | logo_size | logo_title | middleware | module | name | operating system | operating_system | other_names | platform | programming language | programming_language | released | replaced_by | replaces | repo | screenshot | screenshot alt | screenshot upright | screenshot size | screenshot title | screenshot_alt | screenshot_upright | screenshot_size | screenshot_title | service_name | size | standard | title | ver layout | website | qid }}Template:Main other ptx is a Unix utility, named after the permuted index algorithm which it uses to produce a search or concordance report in the Keyword in Context (KWIC) format. It is available on most Unix and Unix-like operating systems (e.g. Linux, FreeBSD). The GNU implementation<ref>At www.gnu.org - The GNU Info entry for PTX using Gnu extensions</ref> uses extensions that are more powerful than the older SysV implementation. The command is available as a separate package for Microsoft Windows as part of the UnxUtils collection of native Win32 ports of common GNU Unix-like utilities.<ref>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref>
There is also a corresponding IBM mainframe utility which performs the same function. Permuted indexes are often used in such places as bibliographic or medical databases, documentation, thesauri, or web sites to aid in locating entries of interest.