Recursive listing

Question

I've been having problems trying to implement something like ls -R on C, The thing is that I need list recursively list everything starting from a given directory and then do stuff with those regular files I get from the list. This is what I have so far:

 void ls(char* path){
    DIR *directory;
    struct dirent *filei;
    struct stat stats;
    directory = opendir(path);
    if (directory != NULL)  
    {
        while ((filei=readdir(directory))!=NULL){
            stat(filei->d_name, &stats);    
            printf(" %s\n", filei->d_name); 
            if (S_ISDIR(stats.st_mode)){
                char *buf = malloc(strlen(path)+strlen(filei->d_name)+2);
                strcpy(buf,path);
                strcat(buf,"/");
                strcat(buf,filei->d_name);
                ls(buf);
            }
        }
        closedir(directory);
    }
    else{
        printf("Error.\n");     
    }
}

It doesn't work at all, it shows files that are not even in the folder I'm working with. Any thoughts? Thanks.

Answer 1

The following rework of your code calls stat() on the full file path, skips over the "." and ".." directories, fixes the memory leak and adds just a touch of error handling:

#define SEPARATOR "/"

void ls(const char *path)
{
    DIR *directory = opendir(path);

    if (directory != NULL)  
    {
        struct dirent *filei;

        while ((filei = readdir(directory)) != NULL)
        {
            if (strcmp(filei->d_name, ".") == 0 || strcmp(filei->d_name, "..") == 0)
            {
                continue;
            }

            char *buffer = malloc(strlen(path) + strlen(filei->d_name) + strlen(SEPARATOR) + 1);
            strcat(strcat(strcpy(buffer, path), SEPARATOR), filei->d_name);

            struct stat stat_buffer;

            if (stat(buffer, &stat_buffer) == 0)
            {   
                printf("%s\n", buffer); 

                if (S_ISDIR(stat_buffer.st_mode))
                {
                    ls(buffer);
                }
            }
            else
            {
                perror(NULL);
            }

            free(buffer);
        }

        closedir(directory);
    }
    else
    {
        perror(NULL);     
    }
}

See if it works any better for you.