rec.c

#include <dirent.h>
#include <stdio.h>
#include <stdlib.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <time.h>
#include <string.h>

#define MAX_PATH_LEN 1024

static int n_files = 0;

static void emit(const char *full_path) {
  struct stat filestat;
  if(stat(full_path, &filestat)) {
    fprintf(stderr, "Failed statting %s\n", full_path);
    return;
  }

  printf("%zd\t%zd\t%s\n", filestat.st_size, filestat.st_mtime, full_path);
  n_files ++;
}

static void recurse_into(const char *path) {
  struct stat dirstat;
  struct dirent *ent, *entp;

  if(stat(path, &dirstat)) {
    fprintf(stderr, "failure while dir-statting %s\n", path);
    return;
  }

  if(!S_ISDIR(dirstat.st_mode)) {
    fprintf(stderr, "trying to recurse into non-directory %s\n", path);
    return;
  }

  DIR *dh = opendir(path);
  if(!dh) {
    fprintf(stderr, "unable to open directory %s\n", path);
    return;
  }

  char *full_path = malloc(MAX_PATH_LEN);
  ent = (struct dirent *)malloc(sizeof(struct dirent) + MAX_PATH_LEN);

  for(;;) {
    if(readdir_r(dh, ent, &entp)) {
      fprintf(stderr, "readdir_r error in %s\n", path);
      break;
    }
    if(!entp) break;
    if(ent->d_type == DT_UNKNOWN) {
      fprintf(stderr, "Skipping DT_UNKNOWN entry %s\n", ent->d_name);
      continue;
    }
    if(strcmp(ent->d_name, ".") == 0 || strcmp(ent->d_name, "..") == 0) continue;
    int p_len = snprintf(full_path, MAX_PATH_LEN - 1, "%s/%s", path, ent->d_name);
    if(p_len >= MAX_PATH_LEN - 1) {
      fprintf(stderr, "Reached MAX_PATH_LEN of %d with %s in %s\n", MAX_PATH_LEN, ent->d_name, path);
      continue;
    }
    if(strchr(ent->d_name, '\n') || strchr(ent->d_name, '\t')) {
      fprintf(stderr, "Detected filename containing newline or tab, skipping.");
      continue;
    }


    if(ent->d_type == DT_DIR) {
      recurse_into(full_path);
    } else if(ent->d_type == DT_REG) {
      emit(full_path);
    }
  }
  closedir(dh);
  free(ent);
  free(full_path);


}

int main(int argc, char *argv[])
{
  for(int i = 1; i < argc; i++) {
    recurse_into(realpath(argv[i], NULL));
  }
  fprintf(stderr, "%d valid files.\n", n_files);
}