Startup {base} | R Documentation |
In R, the startup mechanism is as follows. If a file
`.Renviron', or a file pointed to by R\_ENVIRON
or
`~/.Renviron', exists, it is processed to set
environmental variables. (This is suppressed by the flag
--no-environ
.) See Details for how the file is read.
Then R searches for the site-wide startup profile unless the command
line option --no-site-file
was given. The name of this file is
taken from the value of the R\_PROFILE
environment variable.
If this variable is unset, the default is `$R_HOME/etc/Rprofile'.
This code is loaded into package base
.
Then, unless --no-init-file
was given, R searches for a file
called `.Rprofile' in the current directory or in the user's
home directory (in that order) and sources it into the user
workspace.
It then loads a saved image of the user workspace from `.RData'
if there is one (unless --no-restore-data
was specified, or
--no-restore
).
Finally, if a function .First
exists, it is executed as
.First()
.
The functions .First
and .Last
can be defined
in the appropriate startup profiles or reside in `.RData'.
The commands history is read from the file specified by the
environment variable R_HISTFILE
(default .Rhistory
)
unless --no-restore-history
was specified (or
--no-restore
).
The command-line flag --vanilla
implies --no-init-file
,
--no-restore
and --no-environ
.
.First <- function() { ...... } .Rprofile <startup file>
Lines in a `.Renviron' file should be either comment lines
starting with #
, or lines of the form name=value
.
The latter sets the environmental variable name
to
value
, overriding an existing value. If value
is of the
form ${foo-bar}
, the value is that of the environmental
variable foo
if that exists and is set to a non-empty value,
otherwise bar
. This construction can be nested, so
bar
can be of the same form (as in ${foo-${bar-blah}}
).
Leading and trailing white space in value
are stripped.
No other interpretation of value
is performed. In particular,
if it is enclosed in quotes, the quotes form part of the value.
Prior to R version 1.2.1, `.Rprofile' was sourced after `.RData' was loaded, although the documented order was as here.
The format for `.Renviron' files was changed in version 1.2.0.
Older files are quite likely to work but may generate warnings on
startup if they contained unnecessary export
statements.
.Last
for final actions before termination.