| Sys.setenv {base} | R Documentation |
Sys.setenv sets environment variables (for other processes
called from within R or future calls to Sys.getenv from
this R process).
Sys.unsetenv removes environment variables.
Sys.setenv(...) Sys.unsetenv(x)
... |
named arguments with values coercible to a character string. |
x |
a character vector, or an object coercible to character. |
The names setenv and putenv come from different Unix
traditions: R also has Sys.putenv, but this is now deprecated.
The internal code uses setenv if available, otherwise putenv.
Non-standard R names must be quoted in Sys.setenv:
see the examples. Most platforms (and POSIX) do not allow names
containing "=".
There may be system-specific limits on the maximum length of the values of individual environment variables or of all environment variables.
A logical vector, with elements being true if (un)setting the
corresponding variable succeeded. (For Sys.unsetenv this
includes attempting to remove a non-existent variable.)
Not all systems need support Sys.setenv (although all known
current platforms do) nor Sys.unsetenv.
If Sys.unsetenv is not supported, it will at least try to
set the value of the environment variable to "", with a
warning.
Sys.getenv, Startup for ways to set environment
variables for the R session.
setwd for the working directory.
The help for ‘environment variables’ lists many of the environment variables used by R.
print(Sys.setenv(R_TEST="testit", "A+C"=123)) # `A+C` could also be used
Sys.getenv("R_TEST")
Sys.unsetenv("R_TEST") # may warn and not succeed
Sys.getenv("R_TEST", unset=NA)