Написать(дополнить) программу на Си под Linux

#include <stdio.h>   
#include <dirent.h>    
#include <ctype.h>   
#include <limits.h>  
#include <string.h>  
  
struct search_result  
{  
    char name[PATH_MAX];  
    size_t digits;  
};  
  
static size_t count_digit(const char *str)  
{  
    size_t cnt = 0;  
  
    for (; *str; str++) {  
        cnt += isdigit(*str);  
    }  
  
    return cnt;  
}  
  
static void search_file(struct search_result *result)  
{  
    DIR *cwd;   
    struct dirent *entry;  
    char cwd_path[PATH_MAX];  
    size_t tmp;  
  
    if (!getcwd(cwd_path, PATH_MAX)) {   
        perror("getcwd error");   
        return;  
    }  
  
    if (cwd = opendir(cwd_path)) {   
   
        while ((entry = readdir(cwd))) {  
              
            switch (entry->d_type)  
            {  
            case DT_DIR:  
                if (*(entry->d_name) == '.') {  
                    continue;  
                }  
  
                chdir(entry->d_name);  
                search_file(result);  
                chdir("..");  
                break;  
              
            default:  
                tmp = count_digit(entry->d_name);  
  
                if (tmp > 0) {  
                    if (result->digits == 0 || tmp < result->digits) {  
                        strncpy(result->name, entry->d_name, PATH_MAX);  
                        result->digits = tmp;  
                    }  
                }  
                  
                break;  
            }  
        }   
           
        closedir(cwd);   
    }   
    else {   
        perror("opendir error");   
    }   
}  
  
int main(void)   
{   
    struct search_result result = {0};  
  
    search_file(&result);  
    puts(result.name);  
    return 0;   
}