title: Increase the command window in R
body: <p>I would like to see the results in console and R_HISTSIZE controls the number of lines that are saved (default 512). </p>
  
  <p>Claim that sys.setenv(R_HISTSIZE=Max) solve the history size is not correct and here is the explanation about sys.setenv.</p>
  
  <p>Description</p>
  
  <p>Sys.setenv sets environment variables (for other processes called from within R or future calls to Sys.getenv from this R process).</p>
  
  <p>Sys.unsetenv removes environment variables.
  Usage</p>
  
  <pre><code>  Sys.setenv(...)
  
    Sys.unsetenv(x)
  </code></pre>
  
  <p>Arguments</p>
  
  <p>...
      named arguments with values coercible to a character string.
  x
      a character vector, or an object coercible to character.</p>
  
  <p>Details</p>
  
  <p>Non-standard R names must be quoted in Sys.setenv: see the examples. Most platforms (and POSIX) do not allow names containing "=". Windows does, but the facilities provided by R may not handle these correctly so they should be avoided. Most platforms allow setting an environment variable to "", but Windows does not, and there Sys.setenv(FOO = "") unsets FOO.</p>
  
  <p>There may be system-specific limits on the maximum length of the values of individual environment variables or of all environment variables.
  Values</p>
  
  <p>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.)
  See Also</p>
  
  <p>Sys.getenv, Startup for ways to set environment variables for the R session.</p>
  
  <p>setwd for the working directory.</p>
  
  <p>The help for ‘environment variables’ lists many of the environment variables used by R.
  Examples</p>
  
  <pre><code>  print(Sys.setenv(R_TEST = "testit", "A+C" = 123))  # `A+C` could also be used
    Sys.getenv("R_TEST")
    Sys.unsetenv("R_TEST")
    Sys.unsetenv("R_TEST")  # may warn and not succeed
  </code></pre>
  
  <p>Sys.getenv("R_TEST", unset = NA)</p>