R help - Aug 2009 - Calling C funtion from R help Needed

Hello Forum,

I'm calling C function from R.It is a small sample trial program. The C
function will accept a character and a integer and print them.
It is printing some special character instead of input character. Below are the
C function, Wrapper code ,R code and R output.
Please help me in this issue
Thank you in advance

C function (Name : checkstr.c)
#include<stdio.h>
 int n_char(char n,int m)
{
   int result;
   result = 3;
   //result = strlen(n);
   printf("the string is %c\n",n);
   printf("the silly number is %d\n",m);
  return result;

}

Wrapper Code  (wrapcheckstr.c)
#include <stdio.h>
#include<string.h>

int n_char(char ,int );
void checkstr_R_wrapper(char *n,int *m, int *result)
{ *result = n_char(*n,*m); }

R code (checkstr.c)

checkstr <- function(n,m) {
if (!is.loaded(symbol.C('checkstr_R_wrapper'))) {
dyn.load('checkstr.so') }
 returned_data = .C('checkstr_R_wrapper',
n=as.character(n),m=as.integer(m), result=integer(1))
return(returned_data$result) }

result in R
> source('checkstr.R')
> checkstr('a',3)
Warning in symbol.C("checkstr_R_wrapper") :
  'symbol.C' is not needed: please remove it
the string is ?
the silly number is 3
[1] 3

Hello Forum,

 I'm calling C function from R.It is a 
          small sample trial 
 program. The C function will accept a string and a integer 
 and print them.
 It is giving error segmentation fault. 
          Below are the C function, Wrapper code ,R code and 
 R 
          output.
 Please help me in this issue
 Thank you in 
          advance

Error:

 *** caught segfault ***
address 0x68, cause 'memory not mapped'

Traceback:
 1: .C("checkstr_R_wrapper", n = as.character(n), m =
as.integer(m),     NAOK = TRUE, DUP = TRUE, result = integer(1))
 2: checkstr("hi", 2)

Possible actions:
1: abort (with core dump, if enabled)
2: normal R exit
3: exit R without saving workspace
4: exit R saving workspace
Selection: 1
aborting ...
Segmentation fault



C FUNCTION (Name : checkstr.c)
#include<stdio.h>
#include<string.h>
 int n_char(char n[10],int m)
{
   int result;
   result = 3;
   result = strlen(n);
   printf("the string is %s\n",n);
   printf("the silly number is %d\n",m);
  return result;

}

WRAPPER CODE  
          (wrapcheckstr.c)
#include <stdio.h>
#include<string.h>

int n_char(char,int);
void checkstr_R_wrapper(char **n,int *m, int *result)
{ *result = n_char(**n,*m); }
[proddun@venus myrpackages]$

R CODE(checkstr.R)

source('checkstr.R')
checkstr <- function(n,m) {
if (!is.loaded(symbol.C('checkstr_R_wrapper'))) {
dyn.load('checkstr.so') }
 returned_data = .C('checkstr_R_wrapper',
n=as.character(n),m=as.integer(m), result=integer(1))
return(returned_data$result) }

Thanks and Regards
Naresh P




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