♻ Move utility functions into separate directory

src/utils/fileUtilities.c

@@ -0,0 +1,40 @@
+#include <errno.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include "fileUtilities.h"
+#include "../fileReader.h"
+
+
+//Reads the given amount of bytes from the currently open file into the given buffer.
+void readBytesIntoBuffer(char* buffer, long numBytes) {
+  const size_t result = fread(buffer, 1, numBytes, file.filePointer);
+  file.offset += result;
+
+  if (result != numBytes) {
+    fprintf(stderr, "Could not read %lu bytes from file: %s\n", numBytes, strerror(errno));
+    exit(1);
+  }
+}
+
+
+//Closes the currently opened file and opens the next file at its beginning.
+void openNextFile() {
+  const int closeResult = fclose(file.filePointer);
+  if (closeResult != 0) {
+    fprintf(stderr, "Could not close file: %s\n", strerror(errno));
+    exit(1);
+  }
+
+  //Open next file
+  const size_t fileNameLength = strlen(file.name);
+  //We need to transfer carry if necessary (e.g. .z09 to .z10), otherwise just increase last digit
+  if (file.name[fileNameLength - 1] == '9') {
+    file.name[fileNameLength - 2] += 1;
+    file.name[fileNameLength - 1] = 0;
+  } else {
+    file.name[fileNameLength - 1] += 1;
+  }
+  initFileReader(file.name, 0UL);
+}

src/utils/fileUtilities.h

@@ -0,0 +1,19 @@
+#pragma once
+
+//A structure to store various information needed when reading from a file.
+struct FILE_INFO {
+  char* name;
+  unsigned long size;
+  FILE* filePointer;
+  unsigned long offset;
+};
+
+struct FILE_INFO file;
+
+
+//Reads the given amount of bytes from the currently open file into the given buffer.
+void readBytesIntoBuffer(char* buffer, long numBytes);
+
+
+//Closes the currently opened file and opens the next file at its beginning.
+void openNextFile();

src/utils/min.h

@@ -0,0 +1,5 @@
+//minimum of two integers
+#define min(a,b) \
+  ({ __typeof__ (a) _a = (a); \
+    __typeof__ (b) _b = (b); \
+  _a < _b ? _a : _b; })