/*
 * Compile:	cc -ansi -pedantic -o mcp mcp.c
 * Run:		mcp /path/to/filename > filename.copy
*/

#include <fcntl.h>
#include <stdio.h>
#include <sys/mman.h>
#include <sys/stat.h>

int main(int argc, char* argv[])
{
  struct stat st;
  int fd;
  int flags = MAP_PRIVATE | MAP_NOCORE | MAP_NOSYNC | MAP_PREFAULT_READ;
  char *buffer, *fname;

  if (argc < 1)
    errx(1, "Usage: %s filename", argv[0]);

  fname = argv[1];
  fd = open(fname, O_RDONLY);
  if (fd == -1)
    err("open %s", fname);

  if (fstat(fd, &st) == -1 || !S_ISREG(st.st_mode))
    err("stat %s", fname);
  
  buffer = mmap(NULL, st.st_size, PROT_READ, flags, fd, (off_t)0);
  if (buffer == MAP_FAILED)
    err("mmap %s", fname);

  madvise(buffer, st.st_size, MADV_SEQUENTIAL);
  if (write(1, buffer, st.st_size) == -1)
    err("write");

  return (0);
}