使用 .Call 接口从 C 调用 R 函数并不难.因此，编写一个输入数据的 R 函数，并从 C 中调用它.当您完成一个文件时，UNPROTECT() 将您读入的数据.如下所示

It is not too hard to call R functions from C, using the .Call interface. So write an R function that inputs the data, and invoke that from C. When you're done with one file, UNPROTECT() the data you've read in. This is illustrated in the following

## function that reads my data in from a single file
fun <- function(fl)
    readLines(fl)

library(inline)  ## party trick -- compile C code from within R
doit <- cfunction(signature(fun="CLOSXP", filename="STRSXP", env="ENVSXP"), '
    SEXP lng = PROTECT(lang2(fun, filename)); // create R language expression
    SEXP ans = PROTECT(eval(lng, env));       // evaluate the expression
    // do things with the ans, e.g., ...
    int len = length(ans);
    UNPROTECT(2);                     // release for garbage collection
    return ScalarInteger(len);        // return something
')

doit(fun, "call.R", environment())

一个更简单的方法是反转问题 - 读取两个数据文件，然后用数据调用 C.

A simpler approach is to invert the problem -- read two data files in, then call C with the data.