main.c fixed

#include <dirent.h>
#include <stdbool.h>
#include <stddef.h>
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>

typedef struct fileDir {
  char *src;
  char *dst;
  char *op;
} fileDir;

int main(int argc, char *argv[]) {
  void help();
  fileDir cli(int argc, char *argv[]);
  void process(fileDir d);

  if (argc <= 2) {
    fprintf(stderr, "Please type a name for csv file.\n");
    help();
  }

  fileDir dir = cli(argc, argv);

  process(dir);

  return 0;
}

void process(fileDir d) {
  bool isAudioFiles(char const *name);
  char *getTime(const char *s, char *n);

  DIR *dir;
  struct dirent *entry;

  FILE *file;
  char *path = (char *)malloc(100 * sizeof(char));

  strcat(path, d.dst);
  strcat(path, "/");
  strcat(path, d.op);
  file = fopen(path, "w+");

  if ((dir = opendir(d.src)) == NULL)
    fprintf(stderr, "could't open %s\n", d.src), exit(1);
  else {
    fprintf(file, "NOME,DURAÇÃO\n");
    while ((entry = readdir(dir)) != NULL) {
      if (isAudioFiles(entry->d_name) == true) {
        fprintf(file, "%s,%s", entry->d_name, getTime(d.src, entry->d_name));
      }
    }
    fclose(file);
    closedir(dir);
  }
}

char *getTime(const char *s, char *n) {
  FILE *fp;

  char time[15];

  char *result = (char *)malloc(sizeof(size_t));

  char cmd[100] = "soxi -D";
  strcat(cmd, " ");
  strcat(cmd, s);
  strcat(cmd, "/");
  strcat(cmd, n);

  fp = popen(cmd, "r");

  if (fp == NULL)
    fprintf(stderr, "soxi command failed\n");

  if (fgets(time, 15, fp) != NULL)
    result = time;
  else
    fprintf(stderr, "fgets error\n");

  pclose(fp);
  return result;
}

bool isAudioFiles(char const *name) {
  size_t len = strlen(name);
  if (len > 4 &&
      (strcmp(name + len - 4, ".mp3") && strcmp(name + len - 4, ".mp4") &&
       strcmp(name + len - 4, ".wav")) == 0)
    return true;
  else
    return false;
}

fileDir cli(int argc, char *argv[]) {
  void help();
  int opt;
  fileDir dir = {".", ".", ""};

  while ((opt = getopt(argc, argv, "s:d:n:")) != -1) {
    switch (opt) {
    case 's':
      dir.src = optarg;
      break;
    case 'd':
      dir.dst = optarg;
      break;
    case 'n':
      dir.op = optarg;
      break;
    default:
      printf("Unknown option: %c\n", optopt);
      help();
      exit(1);
    }
  }

  return dir;
}

void help() {
  fprintf(stderr, "\nUSAGE: audio_length [OPTIOMS] -n <FILENAME.csv>\n"
                  "Options:\n"
                  "       -s <path for source directory>\n"
                  "       -d <path for destination file>\n\n");
}