#include <sys/param.h>
#include <unistd.h>
#include <stdlib.h>
#include <string.h>
#include <stdio.h>

/*
 * For reason I do not understand, getopt() and friends are not
 * declared in unistd.h under cygwin.
 */
#ifdef __CYGWIN__
int getopt(int argc, char* const argv[], const char* optstring);
extern char *optarg;
extern int optind;
extern int opterr;
extern int optopt;
#endif

static const char* basename(const char* fullpath)
{
  const char* rv = strrchr(fullpath, (int)'/');
  if( rv == NULL ) {
    rv = fullpath;
  } else {
    ++rv;
  }
  return rv;
}

static void usage(FILE* f, const char* execname)
{
  int rv = 0;
  fprintf(f, "Usage: %s [-h|-v] <path> ...\n", basename(execname));
  if( f == stderr ) {
    rv = 1;
  }
  exit(rv);
}

int main(int argc, char* argv[])
{
  int rv = 0;
  int verbose = 0;
  int ch = -1;
  char** fptr = NULL;
  char* default_argv[] = {
    ".",
    NULL
  };

  /* Process command-line parameters. */
  opterr = 0;
  while( (ch = getopt(argc, argv, "hv")) != -1 ) {
    switch( ch ) {
    case 'h':
      usage(stdout, argv[0]);
      break;
    case 'v':
      verbose = 1;
      break;
    case '?':
      /* fall through */
    default:
      usage(stderr, argv[0]);
    }
  }

  /* Adjust argc. */
  argc -= optind - 1;

  /* Adjust argv. */
  {
    char** src = argv + optind;
    char** dst = argv + 1;
    for( ; *src != NULL ; ++src, ++dst ) {
      *dst = *src;
    }
    *dst = NULL;
  }

  fptr = default_argv;
  if( argc > 1 ) {
    fptr = argv + 1;
  }

  for( ; *fptr != NULL ; ++fptr ) {
    char buf[MAXPATHLEN + 1] = "";
    if( realpath(*fptr, buf) == NULL ) {
      fprintf(stderr, "Warning: failed to resolve \"%s\"\n", *fptr);
      rv = 1;
    } else {
      if( verbose ) {
        printf("%s --> ", *fptr);
      }
      printf("%s\n", buf);
    }
  }

  return rv;
}