#include <stdio.h>
#include <stdlib.h>
#include <dirent.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <unistd.h>
#include <assert.h>


/* search for filename in the dirname directory */
void find_file(const char*filename, const char* dirname) {
#if DEBUG
  printf("Searching for file %s in directory %s\n", filename, dirname);
#endif

  DIR* dir = opendir(dirname);
  if(dir == NULL) {
    fprintf(stderr, "cannot open directory %s\n", dir);
    return ;
  }

  struct dirent* cur_dirent = readdir(dir);

  /* browse the entries in the directory */
  while(cur_dirent != NULL) {
    if(strcmp(cur_dirent->d_name, filename) == 0) {
      printf("Found %s/%s\n", dirname, filename);
    }

    if(strcmp(".", cur_dirent->d_name) != 0 &&
       strcmp("..", cur_dirent->d_name) != 0) {
      char pathname[1024];
      sprintf(pathname, "%s/%s", dirname, cur_dirent->d_name);
      struct stat s;
      int ret = stat(pathname, &s);
      assert(ret == 0);
      if(S_ISDIR(s.st_mode)) {
	/* pathname is a directory. call find_file recursively */
	find_file(filename, pathname);
      }
    }

    /* get the next entry */
    cur_dirent = readdir(dir);
  }
}

int main(int argc, char**argv) {

  if(argc != 3) {
    fprintf(stderr, "Usage: %s file dirname\n", argv[0]);
    return EXIT_FAILURE;
  }
  char* filename = argv[1];
  char* dirname = argv[2];

  find_file(filename, dirname);

  return EXIT_SUCCESS;
}