How do I add all the files in the current directory to an array from a thread in c?

Question

#include <pthread.h>
#include <stdio.h>
#include <stdlib.h>
#include <dirent.h>

pthread_mutex_t mut1 = PTHREAD_MUTEX_INITIALIZER,
            mut2 = PTHREAD_MUTEX_INITIALIZER,
            mut3 = PTHREAD_MUTEX_INITIALIZER,
            mut4 = PTHREAD_MUTEX_INITIALIZER;
char *buff1, *buff2, *buff3, *buff4;

void *stage1(void *arg)
{
    DIR *dir = (DIR*)arg
    struct dirent *ent;
    if (dir != NULL)
    {
  while ((ent = readdir (dir)) != NULL)
  {
    printf ("%s\n", ent->d_name);
  }
  closedir (dir);
  } else
{
    printf("FAILURE");
}
}

int main(int argc, char *argv[])
{
    if(argc != 6)
{
  printf("Usage: %s <buffsize> <filesize> <uid> <gid> <string>\n", argv[0]);
  return(-1);
}

int buffsize, filesize, uid, gid;
sscanf(argv[1],"%d",&buffsize);
sscanf(argv[2],"%d",&filesize);
sscanf(argv[3],"%d",&uid);
sscanf(argv[4],"%d",&gid);

char *string = argv[5];

buff1 = malloc(buffsize * sizeof(*buff1));
buff2 = malloc(buffsize * sizeof(*buff2));
buff3 = malloc(buffsize * sizeof(*buff3));
buff4 = malloc(buffsize * sizeof(*buff4));

pthread_t th1,th2,th3,th4,th5;

    DIR *dir = opendir(".");

pthread_create(&th1,NULL,stage1,dir);

if(filesize != -1) pthread_create(&th2,NULL,stage2,buff2);

return 0;
}

This seems to work fine in the debugger but when I run it nothing is displayed on the terminal. I will be replacing the printf line in the stage1 method with:

buff1[i] = ent;
i++;

I will add more code to make sure that i always points to the right location but this is what i'm working with now. I would like it to print the files so I know that it works.

Answer 1

Your main thread is exiting, ending the process, before your worker thread has time to do anything. Add a call to pthread_join() at the end of main():

    pthread_t th1,th2,th3,th4,th5;
    DIR *dir = opendir(".");

    pthread_create(&th1, NULL, stage1, dir);

    if (filesize != -1)
        pthread_create(&th2, NULL, stage2, buff2);

    pthread_join(th1, NULL);

    if (filesize != -1)
        pthread_join(th2, NULL);

    return 0;
}