Program to use for the |K| command. Environment variables are expanded |:set_env|. ":help" may be used to access the Vim internal help. (Note that previously setting the global option to the empty value did this, which is now deprecated.) When the first character is ":", the command is invoked as a Vim Ex command prefixed with [count]. When "man", "man -s" or an Ex command is used, Vim will automatically translate a count for the "K" command and pass it as the first argument. For "man -s" the "-s" is removed when there is no count. See |option-backslash| about including spaces and backslashes. Example: > :set keywordprg=man\ -s < This option cannot be set from a |modeline| or in the |sandbox|, for security reasons.