#include <unistd.h>
#include <errno.h>
#include <limits.h>
#include <string.h>
#include "syscall.h"

char* getcwd(char* buf, size_t size) {
  char tmp[PATH_MAX];
  if (!buf) {
    buf = tmp;
    size = PATH_MAX;
  } else if (!size) {
    errno = EINVAL;
    return 0;
  }
  if (syscall(SYS_getcwd, buf, size) < 0)
    return 0;
  return buf == tmp ? strdup(buf) : buf;
}