a non-empty character string or an  R  function that sets the default text
editor, e.g., for ` [ edit ](/link/edit?package=base&version=3.6.2) ` and ` [
file.edit ](/link/file.edit?package=base&version=3.6.2) ` . Set from the
environment variable ` EDITOR ` on UNIX, or if unset ` VISUAL ` or ` vi ` . As
a string it should specify the name of or path to an external command.

` example.ask ` :

    

default for the ` ask ` argument of ` [ example
](/link/example?package=base&version=3.6.2) ` .

` help.ports ` :

    

optional integer vector for setting ports of the internal HTTP server, see ` [
startDynamicHelp ](/link/startDynamicHelp?package=base&version=3.6.2) ` .

` help.search.types ` :

    

default types of documentation to be searched by ` [ help.search
](/link/help.search?package=base&version=3.6.2) ` and ` [ ??
](/link/%3F%3F?package=base&version=3.6.2) ` .

` help.try.all.packages ` :

    

default for an argument of ` [ help ](/link/help?package=base&version=3.6.2) `
.

` help_type ` :

    

default for an argument of ` [ help ](/link/help?package=base&version=3.6.2) `
, used also as the help type by ` [ ? ](/link/%3F?package=base&version=3.6.2)
` .

` HTTPUserAgent ` :

    

string used as the ‘user agent’ in HTTP(S) requests by ` [ download.file
](/link/download.file?package=base&version=3.6.2) ` , ` [ url
](/link/url?package=base&version=3.6.2) ` and ` [ curlGetHeaders
](/link/curlGetHeaders?package=base&version=3.6.2) ` , or ` NULL ` when
requests will be made without a user agent header. The default is ` R
(<version> <platform> <arch> <os>) ` except when  libcurl  is used when it is
` libcurl/7.<xx>.<y> ` for the  libcurl  version in use.

` install.lock ` :

    

logical: should per-directory package locking be used by ` [ install.packages
](/link/install.packages?package=base&version=3.6.2) ` ? Most useful for
binary installs on macOS and Windows, but can be used in a startup file for
source installs _via_ ` R CMD [ INSTALL
](/link/INSTALL?package=base&version=3.6.2) ` . For binary installs, can also
be the character string ` "pkglock" ` .

` internet.info ` :

    

The minimum level of information to be printed on URL downloads etc, using the
` "internal" ` and ` "libcurl" ` methods. Default is 2, for failure causes.
Set to 1 or 0 to get more detailed information (for the ` "internal" ` method
0 provides more information than 1).

` install.packages.check.source ` :

    

Used by ` [ install.packages
](/link/install.packages?package=base&version=3.6.2) ` (and indirectly ` [
update.packages ](/link/update.packages?package=base&version=3.6.2) ` ) on
platforms which support binary packages. Possible values ` "yes" ` and ` "no"
` , with unset being equivalent to ` "yes" ` .

` install.packages.compile.from.source ` :

    

Used by ` [ install.packages
](/link/install.packages?package=base&version=3.6.2) (type = "both") ` (and
indirectly ` [ update.packages
](/link/update.packages?package=base&version=3.6.2) ` ) on platforms which
support binary packages. Possible values are ` "never" ` , ` "interactive" `
(which means ask in interactive use and ` "never" ` in batch use) and `
"always" ` . The default is taken from environment variable `
R_COMPILE_AND_INSTALL_PACKAGES ` , with default ` "interactive" ` if unset.
However, ` install.packages ` uses ` "never" ` unless a ` make ` program is
found, consulting the environment variable ` MAKE ` .

` mailer ` :

    

default emailing method used by ` [ create.post
](/link/create.post?package=base&version=3.6.2) ` and hence ` [ bug.report
](/link/bug.report?package=base&version=3.6.2) ` and ` [ help.request
](/link/help.request?package=base&version=3.6.2) ` .

` menu.graphics ` :

    

Logical: should graphical menus be used if available?. Defaults to ` TRUE ` .
Currently applies to ` [ select.list
](/link/select.list?package=base&version=3.6.2) ` , ` [ chooseCRANmirror
](/link/chooseCRANmirror?package=base&version=3.6.2) ` , ` [ setRepositories
](/link/s