On 13 August 2009 at 21:53, Dirk Eddelbuettel wrote:
| I would like to simulate the effect of the command-line option --quiet from
| user-level scripts and startup code. From src/main/CommandLineArgs.c I learn
| that Rp->R_Quiet is set, and I see how that is used in main/main.c.
|
| I would use this from code in Rprofile.site. In other words, I want to be
| silent when --quiet is used (as e.g. by littler or Rscript) but not by R
| itself in normal interactive mode or from ESS.
|
| But it seems that I cannot get to this variable outside of the main
| interpreter. Could this symbol be exported?
Apparently one cannot from user-space at the R level. But by poking into the
not-exported-and-susceptible-to-changes R_ext/RStartup.h header, one can. So
here is a quick littler script using Oleg's inline package:
#!/usr/bin/r
suppressMessages(library(inline))
fn <- cfunction(signature(x="integer"), # can't we have
void functions?
body="structRstart rp;
Rstart Rp = &rp;
R_DefParams(Rp);
if (Rp->R_Quiet) Rprintf(\"(quiet) Hello,
world!\\n\");
if (!Rp->R_Quiet) Rprintf(\"(not quiet) Hello,
world!\\n\"); ",
includes="#include <R_ext/RStartup.h>",
convention=".C")
fn(1)
which runs as expected:
~/R/misc$ ./inline_Rprintf.r
(not quiet) Hello, world!
~/R/misc$
I still see use for a variant of cat() or warning() or something that could
this test from userspace. If anyone at R Core agrees, I could submit a
modest patch
Dirk
--
Three out of two people have difficulties with fractions.